Finding the Best Thickness Run Parameterization for Optimization of Tailor Rolled Blanks

Tailor Rolled Blanks (TRB ) are an established lightweight application for highly stressed structural parts in automotive industry. By varying the rolling nip parts with load adapted thickness profiles and continuous transitions are manufactured. The rolling process is subjected several manufacturing constraints like the maximal thickness reduction or the maximal slope. Typical benefits of using TRB are weight reduction, part integration or fine tuning of performance. Different to other tailored blank technologies the number of thicknesses does not drive the part cost. In order to design the thickness run and efficiently find lightweight potentials optimization techniques are used. There are some publications on this field (Chuang 2007; Duan 2016) using different parametrization approaches. The question is: How to find a good or the best thickness run parameterization for a given problem? In this contribution, we compare different parametrization approaches. The optimization problem is formulated for the use in typical automotive development processes. LS-OPT is used for metamodel-based optimization of a hotformed sheet metal profile subjected to different loadcases coming from static and crash requirements. Radial Basis Functions (RBF) are used as metamodels in conjunction with adaptive simulated annealing (ASA) as optimization algorithm. Results are compared on behalf of performance, mass and function calls. As a result we present recommendations for the best thickness run parametrization subject to the given loadcases or optimization problem formulation. Literature Chuang, C. H.; Yang, R. J.; Li, G.; Mallela, K.; Pothuraju, P. (2007): Multidisciplinary design optimization on vehicle tailor rolled blank design. In: Struct Multidisc Optim 35 (6), S. 551–560. DOI: 10.1007/s00158-007-0152-0. Duan, Libin; Sun, Guangyong; Cui, Junjia; Chen, Tao; Cheng, Aiguo; Li, Guangyao (2016): Crashworthiness design of vehicle structure with tailor rolled blank. In: Struct Multidisc Optim 53 (2), S. 321–338. DOI: 10.1007/s00158-015-1315-z.