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

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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