Abstract
This paper discusses a multidisciplinary optimisation technique applied to a car front end. The loading conditions considered in this optimisation refer to frontal crash and NVH.
Shape and size variables have been considered in the problem.
To reduce the number of design variables in the complete F.E. model, a preliminary case study on the crash member alone was completed and the best triggers design to maximise energy absorption defined ; this lead to a base design for the car front end.
The following outputs have been considered for the multi-disciplinary optimisation problem :
· energy absorption for crash behaviour
· local inertance for NVH behaviour
Each response has been evaluated by mean of numerical FE analysis : Mecalog Radioss and
MSC Nastran were used.
Response surface methods have been used to manage objective and constraint functions in the optimisation problem ; the Interpolating models have been emphasised with respect to the
Regressive ones. A new SW for optimisation CE
2(Computer Experiments for Concurrent
Engineering) has been introduced.
Optimisation tools have been finally used to weight Response Surfaces from crash and dynamic to find a global compromise, with an improved behaviour with respect to all the requirements.