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Dr. Reinold Hagen Stiftung
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ENGINEERING für die Blasformtechnik
The simulation and optimization workflow for extrusion blow
molded parts and how it benefits from the VMAP Interface
Standard
1) Dr. Reinold Hagen Stiftung, Bonn
2) TREE-Institut Hochschule Bonn-Rhein-Sieg, Sankt Augustin
Dr. Olaf Bruch1,2
Patrick Michels1
Dirk Grommes1
Dr. Reinold Hagen Stiftung Kautexstraße 53
53229 Bonn www.hagen-stiftung.de
3DEXPERIENCE® Conference
Darmstadt, 19.-21. November 2019
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Content
1. Introduction
2. CAE-Workflow of blow molded plastic parts
3. The demand for interfaces
• Process dependent material properties
• Local surface film coefficients
• Deformed structure and residual stresses
4. The VMAP interface standard
5. Summary and outlook
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1. Introduction Extrusion Blow Molding
Consumer packaging
Industrial packaging
Technical parts and automotive
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1. Introduction The Extrusion Blow Molding Process
1. extrusion of the parison
2. closing of the mold
3. inflation of the parison
4. opening of the mold / article removal
5. post-machining / deflashing
Wall thickness is a process dependent factor!
Picture source: Thielen, Michael; Hartwig, Klaus; Gust, Peter,
Blasformen von Kunststoff-Hohlkörpern Carl Hanser Verlag, Munich,
2006
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2. CAE-Workflow of blow molded plastic parts Blow molding
simulation
Blow Molding Simulation
Cooling Simulation
Shrinkage and Warpage
Process Simulation Product Simulation Material Modelling and
Interfaces
Drop Test (crash)
Top Load Test (short-term)
Stacking Test (long-term)
Model Calibration
Spannungs - Dehnungs - Kurve des Gsell Materialmodells
0
10
20
30
40
50
60
70
80
90
100
0 0.2 0.4 0.6 0.8 1 1.2
Dehnung
Sp
an
nu
ng
in
N/m
m²
Dehnrate = 1/s
Dehnrate = 10 /s
Dehnrate = 100 /s
Dehnrate = 1000 /s
Blow Molding Simulation Mapping
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2. CAE-Workflow of blow molded plastic parts Blow molding
simulation
Feasibility studies and prediction of wall thickness
distribution
Guide Wall in Dual Cavity
Automotive fuel tank
Optimization of wall thickness distribution
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2. CAE-Workflow of blow molded plastic parts Shrinkage and
Warpage
Blow Molding Simulation
Cooling Simulation
Shrinkage and Warpage
Process Simulation Product Simulation Material Modelling and
Interfaces
Drop Test (crash)
Top Load Test (short-term) Model Calibration
Mapping
Spannungs - Dehnungs - Kurve des Gsell Materialmodells
0
10
20
30
40
50
60
70
80
90
100
0 0.2 0.4 0.6 0.8 1 1.2
Dehnung
Sp
an
nu
ng
in
N/m
m²
Dehnrate = 1/s
Dehnrate = 10 /s
Dehnrate = 100 /s
Dehnrate = 1000 /s
Cooling Simulation
Shrinkage and Warpage
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2. CAE-Workflow of blow molded plastic parts Shrinkage and
Warpage
Process simulation Cooling Simulation Shrinkage &
Warpage
Wall thickness distribution
Local strain and stresses
Temperatures
Residual stresses Displacements
fu
lly o
r se
qu
en
tial
ly c
ou
ple
d
CFD-Simulation of the cooling
channels
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2. CAE-Workflow of blow molded plastic parts Virtual product
testing
Blow Molding Simulation
Cooling Simulation
Shrinkage and Warpage
Process Simulation Product Simulation Material Modelling and
Interfaces
Drop Test (crash)
Top Load Test (short-term)
Stacking Test (long-term)
Model Calibration
Mapping
Spannungs - Dehnungs - Kurve des Gsell Materialmodells
0
10
20
30
40
50
60
70
80
90
100
0 0.2 0.4 0.6 0.8 1 1.2
Dehnung
Sp
an
nu
ng
in
N/m
m²
Dehnrate = 1/s
Dehnrate = 10 /s
Dehnrate = 100 /s
Dehnrate = 1000 /s
Drop Test (crash)
Top Load Test (short-term)
Stacking Test (long-term)
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2. CAE-Workflow of blow molded plastic parts Virtual product
testing
Top-Load-Test Internal pressure test
Drop test
Short term
Crash
Creep/Relaxation
Long term
Jerry can
Fuel tank
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3. The demand for interfaces
Blow Molding Simulation
Cooling Simulation
Shrinkage and Warpage
Process Simulation Product Simulation Material Modelling and
Interfaces
Drop Test (crash)
Top Load Test (short-term)
Stacking Test (long-term)
Model Calibration
Mapping
Spannungs - Dehnungs - Kurve des Gsell Materialmodells
0
10
20
30
40
50
60
70
80
90
100
0 0.2 0.4 0.6 0.8 1 1.2
Dehnung
Sp
an
nu
ng
in
N/m
m²
Dehnrate = 1/s
Dehnrate = 10 /s
Dehnrate = 100 /s
Dehnrate = 1000 /s
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3. The demand for interfaces Process dependent material
properties
Varying wall thicknesses and stretching ratios result in
varying local material properties
780790800810820830840850860870
1 1,5 2 2,5 3 3,5 4Ela
stic M
od
ulu
s [N
/mm
² ]
Degree of stretching λ / stretching ratio Φ [ - ]
E1(Φ) E2(Φ)
experimentally
confirmed
a) b) c)
d)
Distribution of elastic modulus in a typical blow molded bottle
a) Stretching ratio b) Local elastic moduli in principal directions
c) Regression function
F[-] E1 [N/mm²] E2 [N/mm²]
Process simulation of a handle bottle
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3. The demand for interfaces Process dependent material
properties
Interface Dr. Reinold Hagen Stiftung:
Identification of the degree of stretching and
the orientation
Mapping of: • Local wall thickness • Local strain and stress •
Local orientation • Local temperatures
Input Data (Struct. FEA) • Local wall thickness • Local elastic
moduli • Local orientation • Local temperatures
ABAQUS Simulation Model
Material Data: Calculation of the
process-dependent elastic modulus
Loads, boundary conditions etc.
Process Mesh
Structural Analysis
Mesh
Process Simulation B-SIM (Accuform)
Data Exchange Interface
Model alignment
Data transfer
Interface Dr. Reinold Hagen Stiftung
Procedure:
• Deformation state
• Deformation gradient
• Polar decomposition
• Main axes transformation
Undistorted mesh (parison)
Distorted mesh (blown part)
Fraunhofer SCAI MpCCI Mapper
Interface between Acuform/BSIM and Simulia/Abaqus
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3. The demand for interfaces Process dependent material
properties
Principal Direction 1 (max. stretch)
Principal Direction 2 (min. stretch)
Orientation of maximum and minimum stretch in principal
directions Mapped onto structural mesh of an typical blow molded
bottle
Import into Abaqus: e.g. *Elastic in combination with
*Distribution
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Deformed shape after the shrinkage and
warpage simulation
3. The demand for interfaces Deformed structure and residual
stresses
Transfer of • deformation state • residual stresses
Top-Load-Test Internal pressure
Drop test
Short term
Crash
Creep/Relaxation
Long term
Import into Abaqus: *Import or *Initial conditions in
combination with SIGINI User Subroutine
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3. The demand for interfaces Local surface film coefficients
Cooling simulation
Determination of local heat transfer coefficients
Mapping
CFD simulation Flow of cooling water
inside of mold
Altair/AcuSolve
Abaqus
Import into Abaqus: *CFILM
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4. The VMAP interface standard
Interoperability of Engineering Data within Integrated CAE
Workflows
• defined international standard
• integrated import/export and translation tools
• supported by leading software vendors
The VMAP standard and import/export interface tools will provide
users with a vendor-neutral methodology of transferring material
and engineering data between different CAE software along the whole
simulation process chain.
http://vmap.eu.com/
• hybrid modelling of consumer products (Philips) • composite
component in aerospace (Convergent) • additive manufacturing
(Bosch)
29 Partners from 6 countries The VMAP project will be
demonstrated by different manufacturing use cases:
• extrusion blow molding (Rikutec, Hagen Stiftung) • composite
light weight vehicles (AUDI, KIT) • injection molding (Bosch)
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4. The VMAP interface standard CAE-Workflow Extrusion blow
molding
Process Simulation Process dependent
material Cooling
Warpage
Structural Analysis
Top-Load Test/ Internal Pressure Test (short-term)
Drop Test (crash)
Creep Test (long term)
B-SIM Custom
Tool CFD simulation
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o Better simulation results through integrative modelling of
blow molded parts and utilizing of specialized CAE-Tools
o High demand for data transfer between different simulation
tools
o Deformations o Stretches and Strain o (Residual) stresses o
Temperatures o Surface heat coefficients o …
o Interface development especially between different CAE-Tools
can be very time consuming
o Reduced development time through utilization of standard
interfaces like VMAP
o VMAP interface standard offers enhanced flexibility to use
different simulations tools
Outlook
o Further support of VMAP through leading ISVs is desirable and
needed
o Simulia/Abaqus currently supported through external Wrapper
tool
o Extension of VMAP standard to other domains (machine and
sensor data, particle and molecular dynamics, multiscale modelling
New proposal: VMAP analytics
5. Summary and outlook
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Thank you for your Attention!