Robust och Multidisciplinär Optimering av Fordonsstrukturer 2009-00314 Fordons- och Trafiksäkerhet Resultatkonferens - 2014 Project Partners Principal applicant: Volvo Car Corporation Project partners: Combitech AB Altair Engineering EnginSoft Nordic AB Dynamore Nordic AB Academic partner: Linköpings Tekniska Högskola Overall Project Objective Find suitable methods for implementing robust and multidisciplinary design optimization in automotive product development process Sandeeep Shetty Robust design optimization Scope Develop efficient methodologies to perform multiobjective robust and reliabilitybased design optimization of large-scale vehicle structures Investigation of approximate modelling techniques to reduce the computational effort of the optimization process Implementation of developed methodologies into the existing product development process Sandeeep Shetty Overall accomplishments Different approaches to evaluate robustness and to perform non-deterministic optimisation have been studied An approach to perform multiobjective reliability-based optimization and robust design optimization is presented and verified using a vehicle side impact crashworthiness application An efficient reliability-based optimization using a combined metamodel and FEbased strategy is proposed and illustrated using industrial examples Comparison between FE-based and metamodel-based robustness analysis has been performed An approach to handle the discrete responses using metamodels is also presented PhD courses – 60hp Sandeeep Shetty Robust design procedure Define problem • • • Inputs and outputs Select Objectives Uncertainties quantification Optimisation strategy Design evaluation Estimation of the mean and standard deviation Select a optimum design Meta model Verification DOE strategy • Design of experiments Verification ‘ Sandeeep Shetty Articles Article -1 Article -2 Article -3 Robustness-analysis Non-deterministic optimization Efficient Reliability-based optimization approach Comparison between FE-based and metamodel-based robustness analysis Comparative study of deterministic and nondeterministic optimization Validation of metamodels New metamodelling approach to handle discrete responses is proposed An approach to perform optimization of large- scale vehicle structural application is presented Conclusion Computational effort is minimised significantly by using meta models Meta-model approach had acceptable accuracy compared to FE-based approach. Conclusion Presented metamodel-based approach was found to be suitable for large-scale deterministic optimization Further improvement in the presented approach is required in the case of non-deterministic optimization Sandeeep Shetty An efficient reliability-based optimization method is proposed and validated using industrial examples Conclusion Proposed method has better accuracy and the method is computationally efficient Documented Results Licentiate thesis S.shetty: Optimization of Vehicle Structures under Uncertainties, Licentiate thesis, Linköping university, Thesis No. 1643 Journal Papers S. Shetty and L. Nilsson: Multiobjective reliability-based and robust design optimisation for crashworthiness of a vehicle side impact, accepted for publication in the international journal of vehicle design. S. Shetty and L. Nilsson: Robustness study of a hat profile beam made of boron steel subjected to three point bending, Submitted for publication. Conference Paper S.shetty: Efficient reliability-based optimization using a combined metamodel and FE-based strategy. published in proceedings of 4th International Conference on engineering optimization (EngOpt2014) Sandeeep Shetty Multidisciplinary design optimization of automotive structures Scope Find an efficient MDO process for large-scale applications that takes the special characteristics of automotive structural applications into account considers aspects related to implementation within an organization and product development process Outcome Description and demonstration of an MDO process that is simpler than multi-level methods fits existing organizations better than sequential response surface methods (SRSM) and direct optimization often more computationally efficient than direct optimization, SRSM and multi-level methods Ann-Britt Ryberg Work performed Literature survey • MDO methods • metamodel-based optimization MDO process Technical report Comparison of MDO methods PhD courses • single-level methods • multi-level methods • optimization courses • solid mechanics courses • etc Conclusion: 75.5 hp A single-level method + metamodels is often the best choice MDO studies Article 1 • different software • different sizes • different methods • description • demonstration on a simple example Conclusion: The process is efficient, flexible, and suitable for common automotive structural MDO applications. The process fits existing organizations and product development processes. etc. Article 2 Experience Ann-Britt Ryberg Licentiate thesis MDO process Application example Front impact Initiation v load case n load case 1 Setup Setup … Design of experiments Metamodel creation Screening 25 15, 7, 11, 12 variables Design of experiments Step 3 Define DOE, run simulations, and extract results. DOE Acceptable accuracy 90, 42, 55, 48 simulations Metamodel creation Step 4 Build, check, and compare metamodels. Metamodels RBF neural networks + Feedforward neural networks Optimization Verification Verification Setup Minimize mass without degrading the disciplinary performances. Step 2 Find important design variables. Variable screening Variable screening Step 1 Define problem (load cases, objectives, constraints, and design variables). Step 5 Find optimum solutions. Step 6 Check results with detailed model. tx05_mid_front intr_mid_front Side impact v intr_upper_side intr_lower_side Roof crush Optimization Adaptive simulated annealing Verification RBFNN: 8% mass red. (1 constr. viol.) FFNN: 12% mass red. d forc_3_roof forc_max_roof Modal analysis Decision freq_m1_modal freq_m2_modal Ann-Britt Ryberg Publications Licentiate thesis LIU-TEK-LIC-2013:1 Metamodel-based design optimization – A multidisciplinary approach for automotive structures by A-B Ryberg http://liu.diva-portal.org/smash/record.jsf;jsessionid=d0d8422fc5bf97e6f729a89c0b32?searchId=1&pid=diva2:601789 Technical report LIU-IEI-R-12/003 Metamodel-based multi-disciplinary design optimization for automotive applications by A-B Ryberg, R D Bäckryd, L Nilsson http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-84701 Article 1 Multidisciplinary design optimization methods for automotive structures by R D Bäckryd, A-B Ryberg, L Nilsson Submitted Article 2 A metamodel-based multi-disciplinary design optimization process for automotive structures by A-B Ryberg, R D Bäckryd, L Nilsson Under revision Ann-Britt Ryberg Futured work Phase II accepted and started Project number: 2014-01340 Aim: • Take researcher from licentiate to PhD. • Continue development of models for industrial problems. • Industrial implementation of the result from earlier project. • Couple the two areas in a combined study and paper..