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TABLE OF CONTENTS
HOW TO ACHIEVE YOUR GOALS ........................................................................................................... 6
WELDING DISTORTION ENGINEERING .................................................................................................................................. 6
WELD QUALITY ENGINEERING ............................................................................................................................................. 8
AVAILABLE WELDING SIMULATION PACKAGES .................................................................................. 11
WELD PLANNER PROFESSIONAL PACKAGE ........................................................................................................................ 12
WELDING ASSEMBLY PACKAGE ......................................................................................................................................... 12
WELDING PACKAGE ............................................................................................................................................................ 12
THE WELDING SIMULATION SOLUTION ............................................................................................................................. 12
WELDING - UNIVERSITY EDUCATION ................................................................................................................................. 12
PREPARATION OF THE CAD MODEL ................................................................................................... 13
DISTORTION ENGINEERING - QUICK EVALUATION ............................................................................. 14
IMPORT FROM VISUAL MESH .............................................................................................................................................. 14
LOOKING INTO JOINT DETAILS ........................................................................................................................................... 15
GENERATE NEW JOINTS ...................................................................................................................................................... 15
DISPLAY / INVERSE THE RUNNING DIRECTION OF JOINTS ................................................................................................. 16
SPLIT JOINTS IN DISCONTINUOUS SECTIONS ...................................................................................................................... 16
MODEL THE PROGRESSION OF WELDING FABRICATION .................................................................................................... 17
DETERMINE THE LENGTH OF WELDING JOINTS ................................................................................................................. 17
CHECK THE JOINT SIZE THAT WILL SHRINK ....................................................................................................................... 17
DEFINE / CHECK PROPERTIES OF CLAMPS .......................................................................................................................... 18
DEFINE / CHECK PROPERTIES OF OBJECTS ......................................................................................................................... 18
DEFINE THE WELD PLAN..................................................................................................................................................... 19
SOLUTION ............................................................................................................................................................................ 20
Generate the Input for the Solution .............................................................................................................................. 20
Generate the Input for a Transient Solution in VISUAL WELD ..................................................................................... 20
Solve the Project ............................................................................................................................................................ 20
POST-PROCESSING ............................................................................................................................................................... 21
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Load the Result File ....................................................................................................................................................... 21
Display Results............................................................................................................................................................... 22
Tolerance Evaluation .................................................................................................................................................... 23
Stresses and Plastic Strains .......................................................................................................................................... 23
COMPENSATION - EXPORT OF THE DEFORMED GEOMETRY .............................................................................................. 24
Modification of the Mesh Coordinates with Computed Results.................................................................................. 24
DISTORTION ENGINEERING - PROCESS SECURITY .............................................................................. 25
SECURE THE WELDING FABRICATION ................................................................................................................................ 25
SET UP AND RUN THE SIMULATION IN 9 EASY STEPS ........................................................................................................ 25
Step 1 Project Description ....................................................................................................................................... 25
Step 2 Definition of the Global Parameters ............................................................................................................ 26
Step 3 Definition of Component Properties ............................................................................................................ 27
Step 4 Definition of the Welding Process ................................................................................................................ 27
Step 5 Definition of Cooling Conditions ................................................................................................................. 28
Step 6 Definition of Clamping Conditions .............................................................................................................. 28
Step 7 Definition of Loads and Deformations ........................................................................................................ 29
Step 8 and 9 Definition of Solver Parameters and Solution Launch ..................................................................... 29
POSTPROCESSING................................................................................................................................................................. 30
PRECISION DISTORTION ENGINEERING FOR HUGE MODELS .............................................................. 33
GLOBAL MODEL SIMULATION PAM-ASSEMBLY ...................................................................................................... 34
WELD PARAMETERS AND VIRTUAL MATERIAL DATA GENERATION / MANAGEMENT ....................... 41
WELDWARE ..................................................................................................................................................................... 41
WELDING PARAMETERS ........................................................................................................................................... 42
DETAILS OF THE WELDING PARAMETERS ........................................................................................................... 43
VALIDATION OF THE COOLING TIME ................................................................................................................... 44
PRE-HEATING .............................................................................................................................................................. 45
WELD GEOMETRY PARAMETERS ............................................................................................................................ 46
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POST-WELD PARAMETERS ....................................................................................................................................... 47
MATERIAL DATA GENERATION AND MANAGEMENT ....................................................................................... 48
WELDING CCT DIAGRAMS........................................................................................................................................ 48
MECHANCIAL PROPERTIES DEPENDING ON COOLING RATES ..................................................................... 50
Calibration of Yield Stress and Strain Hardening ....................................................................................................... 51
Calibration of PHase Transformations ........................................................................................................................ 52
Material Data Manager ................................................................................................................................................ 53
WELD QUALITY FABRICATION DETAILS ........................................................................................... 54
SINGLE-PASS AND MULTI-PASS WELDING WITH A COUPLE OF PASSES ........................................................................... 54
WORKFLOW ......................................................................................................................................................................... 56
SELECTED EXAMPLES AND COMPUTED RESULTS .............................................................................................................. 56
MULTI-PASS WELDING FOR THICK MATERIAL WITH MANY PASSES ............................................................................... 64
SPOT WELDING .................................................................................................................................. 66
DISTINCTIVE COMPETENCE ................................................................................................................ 68
GENERAL FEATURES ........................................................................................................................................................... 68
WELDING DEDICATED GENERAL CAPABILITIES ................................................................................................................ 68
WELDING DEDICATED MESHING ........................................................................................................................................ 68
GENERAL SOLVER CAPABILITIES ....................................................................................................................................... 69
WELDING DEDICATED SOLVER CAPABILITIES ................................................................................................................... 69
WELDING DEDICATED POST PROCESSING FOR TRANSIENT WELDING ............................................................................. 71
FAST SHRINKAGE METHODS ............................................................................................................................................... 71
LOCAL GLOBAL DEDICATED GRAPHIC USER INTERFACE AND SOLVER CAPABILITIES ................................................... 71
WELDING DEDICATED GRAPHIC USER INTERFACES ......................................................................................................... 72
CHAINING WITH SHEET METAL FORMING .......................................................................................................................... 72
CHAINING WITH HEAT TREATMENT FOR POWER TRAIN APPLICATIONS .......................................................................... 73
GETTING VALUE ................................................................................................................................. 73
GENERAL OBJECTIVES ........................................................................................................................................................ 73
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INDUSTRIAL BENEFITS ........................................................................................................................................................ 74
IMPROVEMENT OF THE PERFORMANCE AND QUALITY OF THE PRODUCT ......................................................................... 75
DISTORTION ENGINEERING COST REDUCTION.............................................................................................................. 76
POSITION IN THE PRODUCT CY CLE ..................................................................................................................................... 76
GETTING DETAILED INFORMATION FOR R&D .................................................................................... 78
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HOW TO ACHIEVE YOUR GOALS
WELDING DISTORTION ENGINEERING
Your goal is to get a stress minimized welding assembly within tolerances at minimum cost, keeping the specs and
securing the production.
Distortion needs to be kept within tolerances.
Tell me the stress level in the structure and I tell you how good the design is is often heard. Residual stresses can
cause a change of shape in cases of painting or assembly changes when the assembled body is modified to fit design
variants. Residual stresses have a negative impact on fatigue.
You want to
Keep distortion within given tolerances
Develop a weld plan
Identify distortion directions and magnitude
Minimize gap fit up forces
Minimize deviation from fixture forces
Minimize the amount of weld consumables needed
Minimize clamp tooling
Reduce the amount of prototyping and distortion repair work
You want to manage all those aspects at their best, at minimum cost, in the minimum time.
Using the Welding Simulation Solution from ESI you will achieve this goal. You can reduce 3-6 months needed for the
design and fabrication planning of complex assemblies by 20% to 50%.
How does it work? First, a quick evaluation of the welded assembly is done using the WELD PLANNER. With simulations
in weld blocks, it takes only minutes to indentify the welds that cause the majority of the distortion. Once identified,
clamping conditions and weld sequences can be optimized for the identified joints. This takes again only minutes for
each variant. The optimization of the clamping tools without simulation is a difficult task the more clamped, the
more stresses will be conserved in the structure, which is completely the contrary of the goal. The less clamped, the
more distortion develops, but the tolerances need to be kept. The WELD PLANNER will help you to quickly find the best
compromise, in less than a day. At the end of the evaluation, a complete sequence can be performed to confirm the
global picture.
Once the evaluation is carried out which should not take more than half a day to one day based on an existing
mesh the fine tuning of the assembly can be performed with PAM-ASSEMBLY. Focusing on the critical joints, variants
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in energy / unit length of weld, welding process, material variants, etc. can be investigated. At this step, you will add
precision to your decision.
In order to validate and secure the production, you can simulate microstructure, distortion, residual stresses and
plastic strains on the full structure, including all the physics of material and all process details.
The WELD PLANNER writes directly an input deck for VISUAL WELD. The rest is done by the computer. It is done pretty
fast, even for huge welded assemblies the SYSWELD solver is today available in DMP and solves huge problems in
less than a day.
For advanced users today, it is possible to chain the Welding Assembly simulation with sheet metal forming
simulations carried out in PAMSTAMP 2G.
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WELD QUALITY ENGINEERING
Your goal is to get the best possible welded design. You want to secure virtually - your welding manufacturing
processes, including all fabrication details. You want to avoid failure of critical welded designs knowing that even
the failure of a simple weld causes the failure of the design.
You want to
Investigate in detail the distortion, microstructure and residual stress consequences of variants in the
welding fabrication process.
Check the feasibility of welded designs but with high precision.
Avoid backside temperature problems (overheating of critical areas in a weld repair process).
Avoid failure due to a wrong microstructure.
Control and minimize distortion with the highest possible precision.
Control distortion that can cause failure by buckling if the welded member is subjected to compressive
stresses.
Avoid stress corrosion cracking (SCC, unexpected sudden failure of normally ductile metals subjected to a
tensile stress in a corrosive environment).
Avoid failure by producing uniform stress distribution and avoiding stress concentrations.
Uncover residual stress spots all over the design due to the welding fabrication process, and avoid
fatigue problems.
Avoid crack initiation due to tensile stresses at the wrong place
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Minimize the overall residual stress level to avoid problems when painting at high temperatures or
modifying the initial design.
Despite the complex physics of material involved, the tool should be easy and straight forward to use.
You expect nothing but the best possible result quality.
VISUAL-WELD gives you the answers. VISUAL-WELD has been designed with the objective to give you an easy access to
more than 100 man-years of experience in welding simulation. Running the SYSWELD solver, VISUAL-WELD offers the
best possible combination of user-friendliness and result quality. The new DMP version allows you to treat even
huge welding cases in a short time frame.
VISUAL WELD
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Speed up with the DMP version as a function of the processors with the DMP version
0
2
4
6
8
10
0 4 8 12 16 20 24 28 32 36
Nbr Processors
Sp
ee
d U
p
CPU SYSWELD
ELAPSE SYSWELD
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AVAILABLE WELDING SIMULATION PACKAGES
The product offer from ESI GROUP in the field of welding simulation distinguishes between distortion engineering
and weld quality. In order to provide the maximum efficiency, three simulation methods exist. For each method (and
thus for each engineering domain), a dedicated package is available.
Methods, engineering domains and available packages
Distortion Engineering Early design and fabrication planning phase - Shrinkage method Weld Planner
Package
Distortion Engineering Get precision in your decision - Local-global method Welding Assembly
Package
Weld Quality and Residual Stress Engineering - Process security and fabrication details - Transient method
Welding Package
The Welding Simulation Solution includes amongst others single pass welding, multi-pass welding, and spot welding.
The heat effects of arbitrary welding processes can be predicted, allowing distortion engineering, and weld quality
and residual stress control. The Welding Simulation Solution is being successfully applied in the Commercial Vehicle
and Automotive Industry, Heavy Industry, the Energy Industry, Nuclear Industry, and the Shipbuilding Industry. A
significant simulation engineering knowledge base is provided with the software and extensive in-depth training
courses are available on all aspects of welding simulation engineering. The following program packages are available
starting from March 2010.
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WELD PLANNER PROFESSIONAL PACKAGE
This package is dedicated to supporting distortion engineering for large-scale welded assemblies, making use of a
shrinkage method.
Engineers use it to identify, in the shortest possible time range, distortion critical weld joints, clamping conditions
and weld sequences to minimize distortion, and the distortion magnitude.
It includes VISUAL MESH, VISUAL VIEWER, and the WELD PLANNER, which has been developed under the guidance of
INPRO, Daimler, VW and Thyssen. It offers a fast shrinkage method and allows distortion engineering within one day.
WELDING ASSEMBLY PACKAGE
This package is dedicated to supporting distortion engineering for large-scale welded assemblies, making use of the
local-global method.
Engineers use it to compute distortion with precision, including all physics.
It includes VISUAL MESH, VISUAL WELD and PAM-ASSEMBLY. It offers a fast local-global method that allows distortion
engineering for large scale structures including all physics.
WELDING PACKAGE
This package is dedicated to supporting weld quality and structural stress engineering.
It includes VISUAL MESH, VISUAL WELD and VISUAL VIEWER. It offers a transient method with a temperature field that
moves in time on the global structure. It helps you to simulate distortion, weld quality and residual stresses for
single-pass welding, multi-pass welding, spot welding and other welding processes. It is dedicated in particular to
give answers on questions related to temperature field, changes in microstructure, hardening, stresses and material
exposure.
THE WELDING SIMULATION SOLUTION
The Welding Simulation Solution includes all packages.
WELDING - UNIVERSITY EDUCATION
This package is concordant with the Welding Package, but node limited.
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PREPARATION OF THE CAD MODEL
The Welding Simulation Solution is based on the method of Finite Elements. The mesh is generated based
on a CAD model, using VISUAL MESH. All commonly used CAD interfaces are available.
With the Welding Simulation Solution of ESI, you can treat shell, shell-solid and solid structures.
Meshing of the CAD model in VISUAL MESH
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DISTORTION ENGINEERING - QUICK EVALUATION
The WELD PLANNER is used in this first engineering step.
IMPORT FROM VISUAL MESH
In the object tree on the right side, you will find components, welds and clamps. As defined in VISUAL MESH.
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LOOKING INTO JOINT DETAILS
Mark joints in the object tree and look into joint details.
GENERATE NEW JOINTS
Via Weld Seams Weld Detection Find all Welds, new welds are detected wherever components
have nodes in common. You have several options to guide this process.
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You can generate welds in the Menu Weld Seams either under Weld Detection or Weld Definition.
Many options allow you to generate weld joints as you wish.
DISPLAY / INVERSE THE RUNNING DIRECTION OF JOINTS
Click with the right mouse button on a weld joint. You can see animated arrows that show the running
direction. Click on , then display the running direction again. The running direction has been
reversed.
SPLIT JOINTS IN DISCONTINUOUS SECTIONS
In order to be able to simulate a weld joint that is fabricated in discontinuous sections, you can split welds.
The split weld will be automatically deleted, and only the subsets will be kept. You can re-join the subsets
into welds again if required.
Below, the joint has been split in two parts.
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MODEL THE PROGRESSION OF WELDING FABRICATION
In order to simulate the progression of the fabrication of a weld, you do not need to split it. You can rather
define in Process Definition how many fabrication steps you want to simulate along a weld joint.
DETERMINE THE LENGTH OF WELDING JOINTS
The length of welds can be displayed at any time.
CHECK THE JOINT SIZE THAT WILL SHRINK
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Click on Visual Effects Generate Tubes or Generate Spheres. All what is inside the tubes or spheres
will shrink in the simulation.
DEFINE / CHECK PROPERTIES OF CLAMPS
Click on a clamp in the object tree. In the right bottom corner of software window, the properties related
to the marked object are listed and can be defined / modified / checked.
DEFINE / CHECK PROPERTIES OF OBJECTS
Click on any object in the object tree. In the right bottom corner of software window, the properties
related to the marked object are listed and can be defined / modified / checked.
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DEFINE THE WELD PLAN
Display all objects that should be included in the weld plan.
Then click on Process Definition .
Definition of the Welding Sequence
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SOLUTION
GENERATE THE INPUT FOR THE SOLUTION
Click on Input Deck and generate the input files
for the solution. Make sure to choose the computation option (non-linear or linear) prior to generating the
input files. Now you can directly solve using the shrinkage method
GENERATE THE INPUT FOR A TRANSIENT SOLUTION IN VISUAL WELD
A file is written, that contains all groups for a transient analysis as needed by VISUAL WELD. You can load the
file in VISUAL MESH and inspect all generated groups.
SOLVE THE PROJECT
Click on Calculation and solve the project. The
progress is shown in a progress window.
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POST-PROCESSING
LOAD THE RESULT FILE
Click on Result Analysis and load the result file.
Distortion of a car chassis with 2.7m length of weld joints. The sequential simulation takes about 10
minutes.
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Distortion of a bridge segment spanning over several meters. The one step simulation takes around one
minute.
DISPLAY RESULTS
Values of computed displacements can be displayed in an information window. Generate the window
(mark Show / Hide with a hook) and then define the size of the information window with the scroll bar.
Next, select the value you want to display under Label. Zoom into the part and move the nodes you want
to measure inside the information window. You need to click once in the information window before the
display of values is activated.
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Distortion Values
TOLERANCE EVALUATION
With a tool based on Microsoft Excel, you can evaluate tolerances.
Computed distortion (blue) against tolerances (red)
STRESSES AND PLASTIC STRAINS
Stresses and plastic strains are as well computed and can be reviewed with VISUAL VIEWER. The shrinkage
method gives you an idea of the stress level in the structure. You could do a quick evaluation of the fatigue
life at this stage.
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V. Mises stresses as computed with the WELD PLANNER
COMPENSATION - EXPORT OF THE DEFORMED GEOMETRY
MODIFICATION OF THE MESH COORDINATES WITH COMPUTED RESULTS
Load the assembly, load the result and click on Tools Apply Displacements. The mesh coordinates will
be modified with a scaling factor of 1. Then you can export the deformed mesh.
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DISTORTION ENGINEERING - PROCESS SECURITY
SECURE THE WELDING FABRICATION
When you export the mesh with joints and clamps in SYSWELD format, all necessary groups to set up a
transient welding simulation are generated, and you can directly start to define the transient welding
fabrication simulation using VISUAL WELD.
Welding Fabrication Simulation in VISUAL WELD
It will take only 30 minutes to define all the details of the transient welding process, for example energy /
unit length of weld and others. Then you can directly start a transient analysis, including all the physics of
welding, like temperature field, phase transformation, transformation plasticity and so on.
SET UP AND RUN THE SIMULATION IN 9 EASY STEPS
In the following, you get a quick overview on 9 simple steps to set up and run a simulation.
STEP 1 PROJECT DESCRIPTION
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In this first step, the title of the project and the working directory are set. There is the possibility to enter a
description of the project, and the used material.
Project description
STEP 2 DEFINITION OF THE GLOBAL PARAMETERS
Now the global model parameters are set. From the mesh loaded, it usually determines these parameters
automatically. The mesh is prepared with VISUAL MESH.
Global parameters in VISUAL MESH
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STEP 3 DEFINITION OF COMPONENT PROPERTIES
The components are identified in the object tree and in a list of components. Now the material assignment
happens. In case of shell-meshed component, the thickness of the components needs to be entered
additionally.
STEP 4 DEFINITION OF THE WELDING PROCESS
The welding process is defined in this step. Based on an energy / unit length of weld approach, the
definition is simple and safe. In case you want to define or use your own heat source, you can do this at
this stage.
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STEP 5 DEFINITION OF COOLING CONDITIONS
Now the cooling conditions are defined. You can define several different cooling conditions to manage all
kind of natural and forced cooling conditions.
STEP 6 DEFINITION OF CLAMPING CONDITIONS
The clamping conditions are another important factor. You can define rigid and elastic clamping conditions
to match all fabrication situations.
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STEP 7 DEFINITION OF LOADS AND DEFORMATIONS
External loads and deformations are defined to model compensation due to fixture or external loads to
apply for fatigue conditions.
STEP 8 AND 9 DEFINITION OF SOLVER PARAMETERS AND SOLUTION LAUNCH
Only the minimum information is needed at this stage.
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POSTPROCESSING
Temperature field of the transient welding process as computed with VISUAL WELD, taking into account all
the physics of material and welding process details.
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Activation of control boxes via double - click
Animation of the results
Animation of the results
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Comparison of model variants, synchronizaiton of the display, display of the model differences in a new
window and step by step animation
Comparison of the distortion of two variants, display of the difference in a new window
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PRECISION DISTORTION ENGINEERING FOR HUGE MODELS
Welding assembly design and fabrication simulation for large-scale assemblies, using a temperature field
on the global structure, is not fast enough to keep the pace of engineers and designers in the early product
phase. The time-consuming part of such a welding fabrication simulation is the mechanical simulation.
However, what is a large-scale assembly? On a reasonable single processor PC, using a mesh with around
50,000 nodes, around 200 mechanical time steps can be performed in a few hours. One mechanical time
step covers the maximum time needed to cross half of the typical length of the molten zone (the heat
source is moving stepwise) or 1/10th of the time needed to deposit a bead instantaneously. If the total
length of the simulated joints exceeds approximately 100 times the typical length of the molten zone or 20
instantaneous welds, a welding simulation with a temperature field on the global structure starts to be
time consuming.
To overcome this limitation, and to avoid the necessity that designers need to deal with nonlinear Finite
Element simulations on the full structure, the local-global approach has been developed.
First, inner residual forces due to the heat effects of welding are computed remote from the global
structure, on a local model. Then, the residual inner forces are extracted and transferred to the global
model, and the distortion of the global structure is computed.
To be consistent with t8/5 (steel) or t4/1.5 (aluminum) guidelines, various technologies are included to
ensure that the computed internal forces in the local models are representative of the internal forces
actually generated in the global structure.
One advantage of this method against others is the fact that no physics is suppressed and the residual
forces are computed using a sufficient mesh density, which is not possible for large-scale structures.
Another advantage is the fact that all distortion modes are well treated there is no simplification in the
local model. Consequently, precise results can be achieved.
Distortion Engineering is also included in weld quality and stress engineering. The computation time is
however longer, and the maximum feasible part size is determined by the available time and computer
configuration.
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GLOBAL MODEL SIMULATION PAM-ASSEMBLY
Representative Objects that have been treated with Pam-Assembly
After more than five years validation by many industrial partners, PAM-ASSEMBLY is addressed to designers,
planners and manufacturing practitioners to help them quickly simulate distortion due to the heat effects
of welding. PAM-ASSEMBLY computes the displacements after each step of an assembly sequence and after
unclamping. The user is able to optimize, compare and finally select the best possible welding sequence
and choice of clamping tools. PAM-ASSEMBLY does not require any advanced knowledge in simulating the
highly nonlinear physics of welding as it is based on an intuitive process building solution.
In PAM-ASSEMBLY, the local-global method is applied to simulate the effects of welding assembly. It is the
most efficient method for large-scale assembly designs. PAM-ASSEMBLY serves as an easy-to-use front end to
perform welding assembly simulations. The physics of welding is fully treated in the local models, which are
simulated with the VISUAL LOCAL MODEL ADVISOR. The basic idea behind the local-global method
implemented in PAM-ASSEMBLY is to provide precision in Advanced Manufacturing simulation without
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simplification of the physics of welding, whilst remaining user-friendly and efficient with respect to
computation time, even for large-scale assemblies.
PAM-ASSEMBLY includes the following benefits that reduce time needed for simulation engineering to a
minimum.
Local model results are stored in a library, which can be filled offline from the global
simulation. Once generated, the library is available for other simulations as well
Automatic detection of components, welding paths and components to be welded
Graphically guided positioning of cross sections of local models
Fully automatic embedding and mesh linking between local models and the global structure.
This will save more than 90% of the time needed against conventional meshing methods. It
takes into account CAD imperfections
Fully automatic extraction of inner forces from the local model and generation of loads for the
global model
The meshing workflow is illustrated hereafter. It saves 90% of the time against usual methodologies
Positioning of a welding cross section along a weld path
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Insertion of solid elements along the trajectory, taking into account all CAD imperfections
Automatic re-meshing to guarantee a compatible mesh
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Further usage also as shell-only application
Auto-Meshing Application Example
Automatic insertion of welding joints in shell meshed components - Courtesy Automobilarbeitskreis
(German Automotive Industry)
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Positioning of cross sections
Extrusion of cross-sections, taking into account CAD imperfections in the components
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Re-meshing of components for FEM compatibility The mesh is also usable for a shell-solid analysis
Mesh usable for Welding Macro Element or shell analysis
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Details
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WELD PARAMETERS AND VIRTUAL MATERIAL DATA GENERATION / MANAGEMENT
WELDWARE
WeldWare is a modular welding advisory system which serves for the calculation of heat procedures in welding. The output is taken as input for distortion, weld quality and residual stress analysis on complex
structures.
WeldWare is a product from SLV M-V GmbH Rostock / Germany. It works well together with the ESI
Welding Suite.
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WELDING PARAMETERS
WeldWare allows the determination of heat input and pre-heat temperature for the best weld quality.
The heat input module works not only for unalloyed steels but for high alloyed steels as well as aluminium,
titanium or nickel alloys, too.
The cooling time given above depends on the material behaviour during welding (module CCT diagram,
microstructure, and Heat Affected Zone properties). If WeldWare determinates a too high heat input due
to the chosen process to achieve the cooling time the user gets this information, otherwise the calculated
value.
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DETAILS OF THE WELDING PARAMETERS
Based on the computed heat input current, voltage and speed can be determined.
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VALIDATION OF THE COOLING TIME
The cooling time for best weld quality can be determined using idealized geometries.
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PRE-HEATING
In case needed a preheating temperature also can be determined via additional formulas.
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WELD GEOMETRY PARAMETERS
Weld geometry parameters like weld cross section and number of layers can be determined.
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POST-WELD PARAMETERS
In case post-weld heat treatment is needed the best possible parameters can be computed.
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MATERIAL DATA GENERATION AND MANAGEMENT
WELDING CCT DIAGRAMS
Based on the chemical composition a welding CCT diagram can be computed.
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MICROSTRUCTURE DEPENDING ON COOLING RATES
Based on the chemical composition the microstructure can be computed for typical cooling rates.
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MECHANCIAL PROPERTIES DEPENDING ON COOLING RATES
Based on the chemical composition mechanical properties can be computed for typical cooling rates. The
mixture of base and wire material can be computed for carbon or low alloyed steels. Based on the new
chemical composition further analysis can be performed.
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CALIBRATION OF YIELD STRESS AND STRAIN HARDENING
Based on WeldWare or measured data, the yield stress and the strain hardening of phases can be
calibrated depending on the temperature. The data of austenite is hard wired.
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CALIBRATION OF PHASE TRANSFORMATIONS
Based on WeldWare or measured data, the phase transformations can be calibrated for usage in
SYSWELD.
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MATERIAL DATA MANAGER
The material data manager allows gathering all calibrated material data. Thermo-physical properties of all
steel classes are hard-wired. A material database in SYSWELD format can be exported and imported.
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WELD QUALITY FABRICATION DETAILS
In a transient welding simulation, the heat source is applied to the global structure. This method is applied
in case engineers need to investigate the details of the welding fabrication. The temperature field, changes
in microstructure, hardening, distortion, stresses, and the yield stress depending on the microstructure and
material exposure is computed for the complete structure and available for any stored time step.
SINGLE-PASS AND MULTI-PASS WELDING WITH A COUPLE OF PASSES
To validate the process security of welded designs with contiguous welds of thin- and thick-walled
structures, VISUAL WELD is available. The simulation solution of the welding fabrication task is performed by
SYSWELD in black box mode.
VISUAL WELD Multi-Pass Welding
VISUAL WELD helps to plan and set up transient welding simulations of the heat effects of welding, based on
the method of Finite Elements. It performs a task planning and set up for the SYSWELD multi physics solver
and is applicable in all kind of Industries: Commercial Vehicle and Automotive Industry, Ship Building,
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Aerospace and Energy / Nuclear. The major benefits are virtual control of distortion, stresses, hardening,
and microstructure and material exposure.
VISUAL WELD in combination with the SYSWELD solver allows addressing MIG, MAG, TIG, Submerged Arc, and
Electrode, Laser, and Electron Beam Welding processes. All types of metallic material can be treated, as
aluminum alloys series 2000 to 7000, standard and high-strength car body steel, structural steels, high-
strength quenched and tempered structural steels, high-alloy ferritic and pearlitic-martensitic steels, high-
alloy austenitic steels, quenched and tempered steels, case hardening steels, titanium alloys and others.
The welding sequence, the weld time or weld velocity and the energy per unit length of weld can be
manipulated. Complex heat sources can be used on demand. Rigid and elastic clamping conditions help to
model the fabrication conditions based on the real stiffness of the clamping tools.
There is no limitation in the simulation of the physics of the heat effects of welding. The user does not deal
with numerical details the solution process is fully automatic and the necessary material behavior to be
simulated is recognized.
The following fabrication conditions can be included in a simulation:
Pre-heating
Welding with Multiple Sources
Hybrid-Welding
Contiguous joints fabricated in sections
Post heat treatment of joints
Tack welds
Simulation of contact between components
Elastic distortion compensation when clamping
Unclamping and re-clamping
One-directional stops
External loads (gap closing, compensation distortion)
Self weight
It is important to understand that the generic capabilities of SYSWELD offer all capabilities for welding
simulation, also for very advanced analysis, for example chaining with heat treatment simulation, turning,
press fitting, etc. Some of those operations will require an advanced usage of the generic SYSWELD program
and are not available through the shop floor dedicated process definition interface.
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WORKFLOW
Please refer to chapter Distortion Engineering - Process Security. A typical object is displayed below.
SELECTED EXAMPLES AND COMPUTED RESULTS
There is no particular limitation in the possibilities to simulate welding fabrication of welded designs.
Typical examples are components of frames and suspension systems in transportation industry, exhaust
systems, power train components or weld specimen for arbitrary purpose.
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Courtesy SKODA Power Steam Turbine Assembly
Comparison of computed results and measurements
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Specimen - ITER
Comparison of computed results and measurements
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Courtesy Automobilarbeitskreis Chassis component
BMW 1-series, cross tube of front axle carrier, Courtesy BMW
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BMW 1-series, cross tube of front axle carrier, Courtesy BMW Temperature field validation
Generation of geometry and mesh in VISUAL MESH
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Geometry and mesh are done in VISUAL MESH
VISUAL MESH is a state of the art product for meshing CAD geometry
VISUAL MESH includes particular features to support welding simulation
Post-processing in Visual Viewer - Temperature field
Retained martensite
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Distortion after unclamping
Residual stresses in welding direction the effect of phase transformations
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Accumulated plastic strains generated in the austenite phase
Yield stress at the end
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MULTI-PASS WELDING FOR THICK MATERIAL WITH MANY PASSES
Multi-pass welding joints are a very important part of thick walled designs with many passes (50 to 500, to
give an idea). Defects occur very often in such joints. Tensile stresses at the surface have negative influence
on the structure lifetime and the brittle fracture resistance. This is in particular a problem for stress
corrosion cracking at the roots of the welds. Residual stresses create a balanced system of inner forces,
which exists even under no external loading. The welding joints have to be designed and produced with
care.
ESI group has developed a MULTI-PASS WELDING WIZARD for designs with hundreds of passes that helps the
user to manage multi-pass welding. It simplifies significantly the workload of the user. All welds involved in
the multi-pass process are computed according to the scheme initially defined in the Standard Welding
Wizard. When the project is stored the mesh is checked, updated and all input data for the multi-pass
welding simulation is automatically created.
Tools for multi-pass welding
There is no particular limitation in the possibilities to simulate multi-pass welding fabrication of welded
designs. Most examples are from energy and nuclear industry.
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Multi-pass welding Courtesy SERCO
Multi-pass Welding Courtesy AREVA NP (Former FRAMATOME)
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SPOT WELDING
Resistance spot welding is an efficient process to join vehicle body parts. This process involves strong
interactions between electrical, thermal, metallurgical, and mechanical phenomena. With the coupling
between electromagnetism, heat transfer, metallurgy, and mechanics, this process is accurately simulated
with SYSWELD.
This numerical approach makes it also possible to account for the evolutions of the contact surfaces. The
electro-thermal contact conditions are affected on a macroscopic scale by the evolution of the contact
surfaces but also on a microscopic scale in the evolution of electro thermal contact resistances.
Comparison between numerical (Blue and Red line) and experimental nugget size at the end of
heating
It is important to note that this simulation can be considered as a local model and repeated several times
on a global model by using local global approach. The main interest is to analyze and optimize, with very
short computation time, the welding sequences in order to reduce on the global distortion.
A Spot Welding Wizard has been developed to simplify the set up of spot welding simulations.
Workflow of the Spot Welding Wizard
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There is no particular limitation in the possibilities to simulate spot-welding fabrication of welded designs.
Most applications are from Automotive Industry.
Spot welding simulation and validation
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DISTINCTIVE COMPETENCE
GENERAL FEATURES
A complete welding simulation solution
Development team with more than 100 years of experience in welding simulation
All available welding simulation methods widely validated by Science and Industry, also for large
structures (see The Welding Simulation Solution)
Shrinkage, local-global and transient methods
State of the art meshing (VISUAL MESH) with all usual CAD interfaces
State of the art post-processing
WELDING DEDICATED GENERAL CAPABILITIES
Welding material database, definition of properties in Microsoft Excel
Welding heat source database for ARC, Laser and Electron Beam Welding
Dedicated Graphic User Interfaces to set up all available welding simulation methods
Five different methods to simulate the heat effects of welding: Transient, steady state, macro
step, local-global and shrinkage
Chaining with sheet metal forming and crash simulation
Toolbox CD with tutorials covering all welding methods and meshing
Engineering guide covering all aspects of weld modeling
Extended Welding User Guides, including expert knowledge (how to model welding, frequently
asked questions, quick checklist of welding simulation projects etc.)
Dedicated welding training courses
WELDING DEDICATED MESHING
Automatic generation of local models
Solid and / or Welding Macro Element insertion along weld paths based on shell meshed
components and 1D meshed trajectories
Automatic detection of to be welded components
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Automatic detection of the link between trajectories and components
GUI driven comfortable positioning of the cross section of the to-be-inserted 3D welding joints
Automatic extrusion or block methods to insert the 3D welding joints along the weld path
Automatic re-meshing of shell meshed components in order to generate a compatible mesh
between 3D joints and components
Export of shell- or shell-solid meshes for transient, macro step or WME based analysis.
GENERAL SOLVER CAPABILITIES
All options of nonlinear heat transfer, including melting, solidification and phase transformation
enthalpy
All options of nonlinear mechanics, including contact
Birth and death of elements
All options of programming (solver command language, simplified Fortran, Fortran, SYSTUS
interface language)
Many programmable user functions for arbitrary purposes
User defined subroutines, for user defined material laws, element formulations, and many other
purposes
WELDING DEDICATED SOLVER CAPABILITIES
All hereafter-listed capabilities are available for 2D Generalized Plain Strain, Axial-Symmetric, 3D
Solid, Shell, and Shell-Solid computation options, both for thermal-metallurgical and
mechanical-metallurgical computations, including chemistry. Available are linear and parabolic
element shape functions.
Welding and heat treatment dedicated macro language for the generation of welding project
files. It allows a quick integration of the solver in any graphic or data management environment
(for example MS Excel ). This language is one level more general as the usual command
language.
Power input managed through moving heat sources
Predefined heat sources for standard welding tasks
Programmable heat sources
Movement of heat sources along arbitrary paths in space
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Orientation of heat sources in space with reference lines
Automatic management of the heat source movement through start time, end time or velocity
Intensity function along weld-lines, to guarantee a mesh independent and constant power input
GUI supported check of the heat source operation and all heat source parameters
Variable stiffness definitions for surface elements in local reference frames, to simulate realistic
properties of clamping tools
Management of time stepping through practical welding process parameters
Automatic management of the linear system of equation solver and iterative technique (BFGS,
etc.)
All material properties depending on temperature, phases and chemistry
Direct coupling of temperature field and phase transformations in the element formulations
Many different phase transformation kinetics laws
Erase of material history above a user defined temperature, when heating
Birth of material history below a user defined temperature, when cooling
Management of yet to be deposited material through material law or birth and death
Automatic and mesh independent detection of the molten zone shape depending on the power
input
Possibility to mix different materials (laser welding of cast iron and low alloyed carbon steel
using an FeNi wire, to name an example)
Mesh independent management of melting and solidification, by material law.
Mesh independent application of temperature and phase dependent properties
Ideal plasticity, isotropic, kinematic and mixed hardening including phase transformations and
phase dependent material properties.
Dedicated Viscous-Plastic material formulation including phase transformations
Consistent tangent material matrix for isotropic, kinematic and mixed hardening, including
phase transformations
Transformation plasticity
Non-linear mixture of phase dependent mechanical properties
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Non linear geometry
Restoring of strain hardening during phase transformations
Particular linear tetrahedral element formulation to reflect best complex plasticity
Fully automatic solution process
Axial symmetric and 3D resistance welding (Coupling of Electrokinetics, Heat Transfer,
Metallurgy), mechanics including contact
DMP (Distributed Memory Parallel)
WELDING DEDICATED POST PROCESSING FOR TRANSIENT WELDING
Tracking of the evolution of the resulting yield stress of material
Tracking of the evolution of thermal strains (current position in the dilatometer)
Tracking of loads (temperature, thermal strains and phases) in the mechanical result file, to be
able to compare loads and results at the same time in multi-window displays
Comparison of variants
Separation between accumulated plastic strains of alpha and gamma phases
Tracking of the evolution of accumulated plastic strains in the alpha phases after transformation
FAST SHRINKAGE METHODS
The WELD PLANNER offers in a dedicated graphic user interface a fast shrinkage method that
allows shop-floor engineers, designers and planners distortion engineering of large and complex
components within one day
Validated with major German OEMs and suppliers
LOCAL GLOBAL DEDICATED GRAPHIC USER INTERFACE AND SOLVER CAPABILITIES
Local-global method packaged in a GUI usable by practitioners (PAM-ASSEMBLY)
Local Model generation packaged in a GUI usable by practitioners (VISUAL LOCAL MODEL ADVISOR)
Welding Macro Element technology to simulate the local-global approach (unique technology to
transfer inner forces between local and global models, shell behavior (6 DOF) in the Welding
Macro Element area).
Fast local-global method for huge structures
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Local model database including data base management
2D and 3D local models
Local models including multi-passes
Extrusion and block method for the transfer of inner forces between local and global models
Fully automatic transfer of inner forces between local and global model
Sequence and clamping manager
Tacking modeling
Sub-assembly modeling (taking into account an initial defect)
WELDING DEDICATED GRAPHIC USER INTERFACES
VISUAL WELD and WELDING ADVISOR to set up classic transient, macro step and steady state
welding projects
Enhanced WELDING PROJECT CHECKING TOOL
HEAT SOURCE FITTING TOOL to calibrate the heat source
VISUAL WELD for shop floor and planning. Dedicated to applications of contiguous welding in
Commercial Vehicle, Automotive and Aerospace Industry. Enables a complete welding task
definition. Meshing, post-processing and solver run.
HARDNESS COMPUTATION WIZARD
PHASE TRANSFORMATION CALIBRATION TOOL to adjust CCT and IT diagrams
MULTI-PASS WELDING ADVISOR to manage automatically the welding of hundreds of passes
SPOT WELDING ADVISOR to manage automatically the resistance welding of up to 9 sheets with
different material and sheet thickness
MS Excel based WELDING MATERIAL DATA MANAGER
VISUAL LOCAL MODEL ADVISOR, to manage the computation of local models
PAM-ASSEMBLY to manage welding assembly simulations based on the local-global method
VISUAL MESH, state of the art meshing tool with all usual CAD interfaces.
CHAINING WITH SHEET METAL FORMING
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Automated transfer of quantities between sheet metal forming and welding, in both directions
Transfer of quantities managed between different material laws, shell element formulations and
incompatible meshes
Mapping of quantities between different mesh shapes and mesh types
Transfer of component shape, sheet thickness, accumulated plastic strains and stresses
Particular methodology to manage the transfer of quantities between shell and solid elements,
for the purpose of tailored blank welding and stamping
CHAINING WITH HEAT TREATMENT FOR POWER TRAIN APPLICATIONS
All kinds of power train heat treatment, like surface heat treatment, through hardening and
case hardening
Turning of heat treated parts
Mounting of heat treated parts with press fitting
Welding of mounted and heat treated parts
In-service behavior simulation (maximum rpm, external loads etc.)
GETTING VALUE
GENERAL OBJECTIVES
The general objectives that can be achieved with The Welding Simulation Solution are
Market effectively
Reduce costs
Shorten time to market
Reduce downtime
Improve productivity
Increase efficiency
Improve profitability
Gain access to new, global markets
Enhance product quality and reliability
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Introduce innovation
Reduce weight
Reduce scrap and rework
Avoid failure
The Welding Simulation Solution has been designed to get value with respect to the listed
objectives, though computer modeling.
INDUSTRIAL BENEFITS
Using The Welding Simulation Solution, you will be able to
Minimize production cost
Minimize structural weight
Keep distortion within tolerances (distortion engineering)
Develop a weld plan
Minimize product risk in the earliest stage of the product development cycle
Master assembly problems
Ascertain the level & distribution of stresses
Control and minimize hardness and grain size in the fusion- and heat affected zone
Avoid cold cracks
The Welding Simulation Solution helps you to
Improve the product design
Identify better processes or materials
Meet procedure approvals
Meet product acceptance standards
Implement new production methodologies
Meet contract quality requirements
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Your objective to provide the best product possible is achieved by simulation-based process design through
Improved understanding of the effects that lead to distortions and stresses
Subsequent optimization of the product design and the manufacturing processes
A key feature of The Welding Simulation Solution is the sensitivity analysis. The sensitivity parameters
studied are
Welding process itself
Welding process parameters
Process stability (gap)
Welding sequence
Number and length of welding joints
Position of welding joints
Clamping conditions
Design
Material properties
Material combinations
Weld Quality
IMPROVEMENT OF THE PERFORMANCE AND QUALITY OF THE PRODUCT
Controlling material characteristics via the computer can significantly enhance the
performance and quality of a product. Controlling stresses via the computer can
significantly enhance the quality and structures service life.
Stresses control via modeling can:
Reduce weight
Maximize fatigue performance
Lead to quality enhancements
Minimize costly service problems
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The Welding Simulation Solution was specifically developed for this purpose. It offers all existing Finite
Element based methodologies to control material exposure, microstructure and stresses via the computer.
DISTORTION ENGINEERING COST REDUCTION
Designing the welding fabrication via the computer to minimize or control distortion can significantly
reduce fabrication costs.
Fabrication design via modeling can:
Eliminate the need for expensive distortion corrections
Reduce machining requirements
Minimize capital equipment cost
Improve quality
Permit pre-machining concepts to be used
The Welding Simulation Solution was specifically developed for this purpose. It offers all existing Finite
Element based methodologies to control welding fabrication via the computer.
POSITION IN THE PRODUCT CYCLE
The Welding Simulation Solution is placed at the earliest stage of the product cycle to
Study distortion influencing parameters in material, process and design
Take preventive measures for low-distortion welding constructions
Avoid over-dimensioning
The Welding Simulation Solution is placed at the earliest stage of the product cycle to choose the best
Welding process
Type of welding joint
Number and length of welding joints
Sequence and welding direction
Clamping conditions
The Welding Simulation Solution is placed at the earliest stage of the product cycle to
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Choose the best design dimensions regarding cost and weight
Make the design decisions taken more safer
Minimize post-design costs by avoiding failure or repair at a late stage of the product
cycle
Understand the physics which lead to distortions, stresses, material exposure and
failure during in-service behavior
Derive or improve design rules from sensitivity analysis
Understand the differences between adjustment-specimen and real parts
Improve established production processes
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GETTING DETAILED INFORMATION FOR R&D
The Welding Simulation Solution Booklet
This document contains extended information on the simulation of the heat effects of welding and the
coupling with other simulation disciplines, for example:
Applications (on more then 30 pages)
Scientific Work (on more then 20 pages)
Available Software Tools
Available Engineering Tools
Documentation
Key Technology
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Chaining with Stamping and Crash Simulation
Chaining with Fatigue and Structural Analysis
Joining of Large-Scale Structures
Available Simulation Methodologies
Training Courses
And much more