Optimization strategies for Tailor Rolled Parts in car bodys
Design space restrictions and complex requirements of modern modern car body structures lead to sheet metal parts which are rarely fully stressed. The use of flexible rolled material enables light weighting by decreasing the sheet thickness in areas, which are less loaded. The production of such material is characterized by technological constraints and economical specifics. Because of the increased design freedom as well as the complex relationship between function, cost and manufacturability the design of tailor rolled parts is time demanding and thus cost intensive. This thesis presents strategies for the design and optimization of flexible rolled parts that make it possible to incorporate function, cost and manufacturability assessment into a multidisciplinary optimization process. The underlying calculation procedure allows the formability evaluation based on a technology specific finite-element-modelling and enables to carry over the influences of the forming process to the functional evaluation. A cost model is presented, which respects the economic specifics of the tailored rolling process chain. The integrity of the passenger cabin must be guaranteed in the case of an accident, which is why crash load cases have to be taken into account in the design phase. Since their calculation is time consuming, they determine the turnaround time of the optimization. The formulation of the degrees of freedom or rather the parametrization of the thickness run has significant influence on the number of calculations needed. A clever parametrization enables an efficient optimization, respecting the technological constraints as well. Based on the optimization scheme a strategy is developed, which enables the selection of those parts, whose production from tailor rolled material guarantees cost-efficient light weighting.
Shaker Verlag, ISBN: 978-3-8440-7936-4
