Identification by genetic algorithm of a constitutive law taking into account the effects of hydrostatic pressure and speeds

Meeting technical specifications requires the improvement of polymeric material behaviour used in the conception of structural parts notably in the automotive sector. It is in this context that Apollor in collaboration with several industrial groups including Basell, Renault S.A., Renault Truck, Solvay and Visteon coordinated a research and development study on the problematic of polymer behaviour at high strain speeds. The methodology of characterization adopted includes an experimental tool backed up by numeric tools to identify by inverse methods the mechanical parameters of a literature model used in computation software. Thus, effects of hydrostatic pressure and speed on different parameters have been introduced in the model. Then, an identification protocol of the model parameters has been developed. It is based on a genetic algorithm that confers high efficiency.