SHAPE AND SIZE OPTIMIZATION OF ENERGY ABSORBING (EA) FOAMS FOR ROBUST UPPER INTERIOR HEAD IMPACT PROTECTION

摘要

Foams have found predominant application in automotive industry for its Energy Absorption (EA) characteristic and ease of manufacturability. To meet the stringent and evolving Safety regulatory/Consumer metrics requirements (vehicle crashworthiness and occupant protection), automotive industries have used Computer Aided Engineering (CAE) tools extensively during vehicle development to design, iterate and optimize the EA (Energy Absorber) foams, which is often a time-consuming process. Effort here is to integrate an optimization tool that would explore design space and help compute optimal design based on defined constraints. LS-OPT (Optimization tool from Livermore software Technology Corporation) and ANSA (Pre-Processing tool) is used for parameterized morphing to generate various morphing blocks, and the data is fed to Ls-Dyna through LS-OPT interface. A Multi-stage sequential domain reduction technique was adopted for this optimization study which evaluates the DOE based response surface at every design stage and converge the domain towards the optimal solution and LS-OPT verifies the response surface solution with Ls-Dyna evaluation. It is observed that LS-OPT has a seamless interface with tools such as ANSA and LS-DYNA. The Meta-models obtained from LS-OPT can be utilized to predict the objectives by varying the design variables in three dimensional (3D) space. The approach demonstrated good competency and confirms that this procedure is a viable approach that enables engineers to not only optimize design, but also reduce considerable manual effort and time savings.