Research Of Uncertainty Optimization Method And Its Application In Crashworthiness Optimization Design Of Vehicle Body Structure

The uncertainty-based optimization method is crucial in promoting the quality ofthe products. As plenty of deep researches on the uncertainty-based optimizationmethod recently, the surrogate-based uncertainty optimization method is graduallybecoming popular and is favored by more and more designers due to its simplity andhigh efficiency. Nevertheless, relative researches on investigating this method arequite insufficient; therefore, to conduct such researches is meaningful and valuable.The crashworthiness optimization design of Car body is one of the key derections ofvehicle crashing safety research areas, which is a combination of the optimizationmethod and the crashworthiness design engineering problem. However, the everpublished researches mainly focus on improving the crashworthiness behavioursthrough a determined optimization process; thus, the introduction of uncertaintyoptimization method in this area is of crucial meaningful. Based on the abovementioned statements, the main research is listed as the follow three sections.Sec.1. Based on the logic analysis, the defects of the conventional surrogatebased uncertainty optimization method are figured out and the extremal mappingmethod is originated to solve this problem. On basis of this, the DOE reconstructionbased surrogate reconstruction method is originated, which is applied to construct allthe needed functions in the newly originated uncertainty optimization process.Furthermore, the statistical theory is employed here to investigate the precisionfeature of the reconstructed DOE. Additionally, the benchmarks are employed tovalidate the resonableness of the new method and to study and compare the precisioncharacteristics of4kind sorrogates in the uncertainty optimization process, which isaimed to provide desiners with a reference in selection surrogate type.Sec.2. To validate the practicalabilty of the newly originated method, afoam-filled tapered thinwalled structures is employed herein, and both the determisticoptimization method and uncertainty optimization method is applied to maximize itscrashworthiness indicators. The result indicates that the uncertainty basedoptimization has worse crashworthiness behaviours but more reliable constraints andmore robust objective. Besides, the newly originated method can attribute to attainmore reliable result than the conventional uncertainty optimization method, whichfurther indicates the practicalabilty and of superiority the newly originated uncertainty optimization method.Sec.3. Since the uncertainty optimization method is proved to be useful inrealizing crashworthiness optimization purpose, it is employed into thecrashworthiness and lightweight design of the major components of a Rhomboic newconcept car. The results suggest that the optimized design has largely improved thenormal crashing safety of the objective vehicle and maximumly decrease the totalweight of the objective car body structures.