Change search
CiteExportLink to record
Permanent link

Direct link
Cite
Citation style
  • apa
  • harvard1
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf
A directional surrogate model tailored for efficient reliability based design optimization
KTH, School of Engineering Sciences (SCI), Solid Mechanics (Dept.), Solid Mechanics (Div.).
KTH, School of Engineering Sciences (SCI), Solid Mechanics (Dept.), Solid Mechanics (Div.).ORCID iD: 0000-0001-8068-2360
2012 (English)Report (Other academic)
Abstract [en]

Reliability based design optimization (RBDO) aims at minimizing an objective while constraining the failure probability of structural components. Due to the iterative nature of both the minimization and the failure probability validation, there is considerable computational effort associated with it. In this paper, a computationally inexpensive approach for RBDO is presented. The key contribution is the directional surrogate model and its associated advantages; a sound balance between accuracy and computational cost, including the possibility to fit model coefficients based on an optimal experiment design, high fidelity modeling of representative structural responses, treatment of multiple constraints without added computational cost, and straightforward sequential linear programming implementation. The directional surrogate model is of power type with nonlinear behaviour only in the gradient direction, thus balancing accuracy and computational cost. Moreover, information from prior iterations are used in every iteration in a weighted least squares optimization. When benchmarked against existing approaches from the literature using a well known reference problem, it is shown to be highly efficient. It also shows promising stability and convergence rate for additional challenging problems to which it has been applied.

Place, publisher, year, edition, pages
2012. , 15 p.
Series
Trita-HFL, ISSN 1104-6813 ; 518
Keyword [en]
FORM, Surrogate Model, Design of Experiments, Multiple Constraints
National Category
Engineering and Technology
Identifiers
URN: urn:nbn:se:kth:diva-90799OAI: oai:DiVA.org:kth-90799DiVA: diva2:506558
Note
QC 20120229Available from: 2012-02-29 Created: 2012-02-29 Last updated: 2012-03-01Bibliographically approved
In thesis
1. Methods for reliability based design optimization of structural components
Open this publication in new window or tab >>Methods for reliability based design optimization of structural components
2012 (English)Doctoral thesis, comprehensive summary (Other academic)
Abstract [en]

Cost and quality are key properties of a product, possibly even the two most important. Onedefinition of quality is fitness for purpose. Load-bearing products, i.e. structural components,loose their fitness for purpose if they fail. Thus, the ability to withstand failure is a fundamentalmeasure of quality for structural components. Reliability based design optimization(RBDO) is an approach for development of structural components which aims to minimizethe cost while constraining the probability of failure. However, the computational effort ofan RBDO applied to large-scale engineering problems has prohibited it from employment inindustrial applications. This thesis presents methods for computationally efficient RBDO.A review of the work presented on RBDO algorithms reveals that three constituentsof an RBDO algorithm has rendered significant attention; i ) the solution strategy for andnumerical treatment of the probabilistic constraints, ii ) the surrogate model, and iii) theexperiment design. A surrogate model is ”a model of a model”, i.e. a computationally cheapapproximation of a physics-based but computationally expensive computer model. It is fittedto responses from the physics-motivated model obtained via a thought-through combinationof experiments called an experiment design.In Paper A, the general algorithm for RBDO employed in this work, including the sequentialapproximation procedure used to treat the probabilistic constraints, is laid out. A singleconstraint approximation point (CAP) is used to save computational effort with acceptablelosses in accuracy. The approach is used to optimize a truck component and incorporatesthe effect that production related design variables like machining and shot peening have onfatigue life.The focus in Paper B is on experiment design. An algorithm employed to construct anovel experiment design for problems with multiple constraints is presented. It is based onan initial screening and uses the specific problem structure to combine one-factor-at-a-timeexperiments to a several-factors-at-a-time experiment design which reduces computationaleffort.In Paper C, a surrogate model tailored for RBDO is introduced. It is motivated by appliedsolid mechanics considerations and the use of the first order reliability method to evaluate theprobabilistic constraint. An optimal CAP is furthermore deduced from the surrogate model.In Paper D, the paradigm to use sets of experiments rather than one experiment at atime is challenged. A new procedure called experiments on demand (EoD) is presented. TheEoD procedure utilizes the core of RBDO to quantify the demand for new experiments andaugments it by a D-optimality criterion for added robustness and numerical stability.

Place, publisher, year, edition, pages
Stockholm: KTH Royal Institute of Technology, 2012. 86 p.
Series
Trita-HFL. Report / Royal Institute of Technology, Solid mechanics, ISSN 1654-1472 ; 0520
Keyword
Reliability
National Category
Applied Mechanics
Identifiers
urn:nbn:se:kth:diva-90753 (URN)
Public defence
2012-03-12, F3, Linstedtsvägen 26, KTH, Stockholm, 10:00 (English)
Opponent
Supervisors
Note

QC 20120229

Available from: 2012-02-29 Created: 2012-02-28 Last updated: 2013-01-14Bibliographically approved

Open Access in DiVA

fulltext(252 kB)245 downloads
File information
File name FULLTEXT01.pdfFile size 252 kBChecksum SHA-512
0c2fb45a1750017f66db63d5c99699b1d8fcebed20efe12bfd9cb8fbce6e43c273e2377ac8dcbf6500f95cdc807c665edf5f1acf82be0186614e6869f2fa5ef0
Type fulltextMimetype application/pdf

Search in DiVA

By author/editor
Dersjö, TomasOlsson, Mårten
By organisation
Solid Mechanics (Div.)
Engineering and Technology

Search outside of DiVA

GoogleGoogle Scholar
Total: 245 downloads
The number of downloads is the sum of all downloads of full texts. It may include eg previous versions that are now no longer available

urn-nbn

Altmetric score

urn-nbn
Total: 270 hits
CiteExportLink to record
Permanent link

Direct link
Cite
Citation style
  • apa
  • harvard1
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf