Abstract:

In order to further reduce the mass of vehicle control arm， a multi?material topology optimization method for shell/filler structure is proposed. Two groups of design variables are adopted to establish the material interpolation model， in which a two?step filtering is conducted on the first group of design variables and the normalized density gradient norms are used to separate shell region and filler region， while the second group of design variables are used for the assignment of multi?material in filler region. To avoid over aggregation of infill material， the local volume constraint is extended to the issue of multi?material filling by implicit mapping function. The results of calculation example of control arm optimization indicate that the material interpolation model can effectively identify the feature of shell and achieve local volume constraints， the mass of the main part of control arm is 13.2% less than the original steel counterpart， and the stress levels in steering and braking conditions are reduced by 55.0% and 39.7%， respectively， getting a better result of lightweighting.

Key words: automotive control arm, lightweight design, multi?material topology optimization, shell/filler structure, local volume constraint