Optimisation study of a vehicle bumper subsystem with fuzzy parameters

This paper deals with the design and optimisation for crashworthiness of a vehicle bumper subsystem, which is a key scenario for vehicle component design. The automotive manufacturers and suppliers have to find optimal design solutions for such subsystems that comply with the conflicting requirements of the regulatory bodies regarding functional performance (safety and repairability) and regarding the environmental impact (mass). For the bumper design challenge, an integrated methodology for multi-attribute design engineering of mechanical structures is set up. The integrated process captures the various tasks that are usually performed manually, this way facilitating the automated design iterations for optimisation. Subsequently, an optimisation process is applied that takes the effect of parametric uncertainties into account, such that the system level of failure possibility is acceptable. This optimisation process is referred to as possibility-based design optimisation and integrates the fuzzy FE analysis applied for the uncertainty treatment in crash simulations. This process is the counterpart of the reliability-based design optimisation used in a probabilistic context with statistically defined parameters (variabilities).

► Possibility-based design optimisation process that implies fuzzy FE analysis applied in the design for crashworthiness.
► Approach allows the designer to include the effect of non-deterministic model properties in the design performance optimisation.
► Product performance is guaranteed in the presence of uncertainties already from the early design stages.
► Two optimisation scenarios are compared: classical crisp optimisation vs. optimisation with uncertainties.