Author : Amol S. Bhanage, Reshma Jawanjal, Sahil Bhamer, Prabjot Kaur Ture and Manish C Gharti

Dent resistance is one of the major requirements for automotive body panel design. It depends on material strength, thickness, panel geometry/shape and outer and inner panel assembling. A detailed DOE study investigates effects of work hardening, thickness; bake hardening on the denting simulation results. Important parameter affecting CAE denting results are identified which in turn provides guidelines for production application. An FEM simulation method was investigated in order to predict a dent resistance and stiffness performance of automotive exterior body panels. The dent simulation was carried out with material models taking forming effects, such as work hardening and thickness variation into account. Acceleration compensation methodology for dynamic dent testing was successfully applied to calculate dent loads and applied energy in dynamic dent testing. The impact of strain rate on material binding and hardening in high speed dynamic dent resistance testing was studied. A finite element methodology, based on implicit numerical integration procedure, force simulating oil canning test on door assembly is presented. The sensitivity studies are conducted on three different grades of steel for the outer panel. Further studies are conducted to understand the effect of manufacturing (forming operation) on the oil-canning behavior of door assembly. Two finite element methodologies force simulating oil-canning test on closure assemblies are presented. Further reinforcement of the predictability of the methodology is demonstrated by an oil-canning simulation, using the implicit code, of a door assembly.

Keywords: Automotive panels, Dent resistance, FEA, Oil canning, Stiffness