UK ATC 2015: Automated Post Processing of Multimodel Optimisation Data

AUTOMATED POST PROCESSING OF MULTIMODEL OPTIMISATION DATA

Markus Schemat, BMW Group

9TH ALTAIR UK TECHNOLOGY CONFERENCE STRATFORD MANOR 2015

9th UK ATC, 16.06.2015 Page 2

POST PROCESSING OF MMO DATA OPTIMISATION IN THE PRODUCT DESIGN PHASE

Development Change Cost

Product Knowledge

Product Development Timeline

Architecture Phase

Concept Phase

Series Phase

SOP

Design freedom

−What is an optimal solution for an architecture?

−What is an optimal solution for multiple CAE models?

−How to approach an optimal solution in best time?

−Is there a better (global) optimum? Optimisation Potential

To answer this questions the presentation is covering a method which is combining two major approaches

−Multi Model Optimisations (MMO) −Solution Spaces

Both methods are applied to gradient based optimisations

9th UK ATC, 16.06.2015 Page 3

POST PROCESSING OF MMO DATA RESPONSE DATA QUERY INFORMATION GAIN Method Time User

Activity Information

Density Optimum

Global/Local

Discrete ++ -- - --

Stochastic -- + +

Optimisation (Gradient based) + ++ +

Solution Space + ++ ++

Distribution Correlation Postprocessing

Datamining

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POST PROCESSING OF MMO DATA DEFINITION OF SOLUTION SPACE

− The solution space is representing the feasible region of the current design. − It is based on the performed CAE simulations. − The real physical solution space is continuous vs. the linear ones derived from the simulation. − The solution space is limited by design boundaries and response constraints.

Change of Solution Space

Number of CAE Models

Constraint 1

Design variable 1

Architecture 2…N

MDO 2…N

Multimodel (MMO)

Feasible Solution Space

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POST PROCESSING OF MMO GENERATING THE SOLUTION SPACE

Method Pro Con

Stochastic −Equal sample distribution −Parallel job submission −No local optima

−Large # samples −No optimal solution

Optimisation (from Baseline) −Small # of samples −Parallel job submission −Minor chance of local optima

−Unequal sample distribution

Optimisation (Sequential) −Minimal # of samples −Only local samples −Sequential job submission −Potential for local optima

Constraint ≤ 0.28 Constraint

≤ 0.0 Constraint ≤ -0.04

Constraint ≤ -0.13

Constraint ≤ -0.185

Constraint ≤ -0.28

Model #n Approximate

Model

F06

DESVAR #n

PCH

OP2

External Parser

Post processing

Structural Analysis

Sensitivity Analysis

Approximate Optimisation

Improve Design

Optistruct / Nastran - SOL200

H3D

OUT

Model #1 Approximate

Model

F06

DESVAR #1

PCH

OP2

External Parser

Post processing

Structural Analysis

Sensitivity Analysis

Approximate Optimisation

Improve Design

Optistruct / Nastran - SOL200

H3D

OUT

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POST PROCESSING OF MMO OPTIMISATION SETUP – SINGLE MODEL

DESVAR #1

DESVAR #n ≠

Independent solution for each model

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POST PROCESSING OF MMO OPTIMISATION SETUP – MULTIMODEL

DESVAR #1

DESVAR #n =

Linked solution for all models

Model #1 DESVAR

#1

Output External Parser

Post processing

Structural Analysis

Sensitivity Analysis

Approximate Optimisation

Improve Design

Optistruct / Nastran - SOL200

Approximate Model

Model #n

DESVAR #n

Output External Parser

Post processing

Structural Analysis

Sensitivity Analysis

Component Target

Global Stiffness Eigen Modes Energy Absorption Weight

Eigen Modes Dynamic Stiffness Vibration (FR)

Stiffness Eigen Modes Cost

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POST PROCESSING OF MMO DATA EXAMPLE- REQUIREMENT MANAGEMENT

Requirement management

Car Positioning

Dis

cret

isat

ion

of D

evel

opm

ent

Targ

ets

Customer related Functions and Properties

Car

Arc

hite

ctur

e

BIS, TOP3 …

Responsible Department

Function

EG Active Safety Ergonmics Driver Assistance System Fatigue Strength …

EK Comfort Interior BIW Functions Corrosion Protection …

TI Manufacturing Technology Producibility …

EF Driving Dynamics …

… … Ta

rget

Tra

nsla

tion

into

Eng

inee

ring

9th UK ATC, 16.06.2015

Question: Do the component targets (eigen frequency of the steering column on its own) correlate with the global target (vibration at the steering column in the BIW)?

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POST PROCESSING OF MMO DATA GUI - HYPERVIEW CUSTOMIZATION

The MMO postprocessing is implemented as a user customization via the preferences file in the Hyperview GUI.

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POST PROCESSING OF MMO DATA GUI – DATA IMPORT AND CONVERSION

− The import of data is defined via a directory selection

− Folders could be selected individually or by scanning of subfolders.

− All supported output files will be recognized automatic and loaded into a database (Conversion)

− Currently Supported Formats −Optistruct (*.out, *.hgdata) −Nastran SOL200 (*.f06)

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POST PROCESSING OF MMO DATA GUI - CONFIGURATION OF PLOT DATA

−Response selection is performed via the curve labels −Plotting could be done for:

−Response versus response −Response versus desvar/desprop −Responses/desvars of different MMO models

−A filter to preselect the responses/desvars could be applied −An internal constraint is available to reduce the database values and predict influences of design changes

model2_LS+TR:

model1_LS :

model3_LS+TR+RK:

Found MMO Results

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POST PROCESSING OF MMO DATA GUI – DATA ANALYSIS PLOTTING

− The prior configured responses are plotted in a 2D plotting client and shown in a tabular format − The solution space is created automatically for the plotted data − For additional information notes with the response values could be attached to desired points of interest

−Multiple notes could be generated −Filtering of notes is implemented

− Intermediate Points could be interpolated based on the neighboring points and exported as new designvariables

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POST PROCESSING OF MMO DATA GUI – DATA ANALYSIS ANIMATION

− Each design iteration could be visualized into the animation client − The postprocessing is available for

−Individual Optimisations −Solution space

− To review the design changes an animation mode is available − Final or in between results could be exported to an PPT report.

Non Feasible Designspace

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POST PROCESSING OF MMO DATA EXAMPLE- REQUIREMENT MANAGEMENT

Example Summary a. Even without fulfilling local

constraints (eigen frequency

targets) the overall vibration target

could be achieved.

b. The baseline is not weight optimal

c. 3mm/s is the physical limit of the

Response

d. Fixing the cross member is limiting

the weight potential drastically

(blue region)

Maxval = 3 mm/s

Maxval = 12 mm/s

Base

Thickness

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POST PROCESSING OF MMO DATA DATA HANDLING AND PROZESS FLOW

External Parser

(Convert)

Plotting Animation

Export

Model #1

DESVAR

Output Structural Optimiser

Model #n Output

MMO #1

DCONST #1

Model #1

DESVAR

Output Structural Optimiser

Model #n Output

MMO #n

DCONST #2

Scripted

Plotting DB

Animation DB

Preprocessing Solving Postprocessing

Solution Space GUI in Hyperview

Filter Data

Constrain Data

Add new design loops

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POST PROCESSING OF MMO DATA CONCLUSION / Q&A

Conclusion

−The described method is showing great potential in combining Optimisation techniques.

−Multi model Optimisations are extremely helpful for architectural decisions

−The data handling is working well with the Hyperview customization

Outlook

−Currently only gauge is supported in the postprocessing

−Integration of further CAE disciplines

−Export and import of Excel datasheet

−Interpolation of DESVAR Export with gradient based information instead of interpolations

−Postprocessing of Hyperstudy

−Postprocessing of GSO Results