Keywords: aluminium foam, alporas, polystyrene, modeling, finite element method, impact test, energy absorption, high strain rate..

This paper focuses on modeling and simulation of deformation behavior of a sandwich structure composed of closed-cell metal foam, expanded polystyrene and plastic foil. Such a structure is intended to be used for energy absorbing applications such as motorcycle helmets. First, individual materials as well as sandwich panels were tested in a drop tower for different impact velocities to generate high strain rate conditions. The digital image correlation method was employed to use stress-strain curves at three impact speeds. Second, virtual experiments with selected strain rate sensitive constitutive models were performed to best fit the experimental results. Good correlation between experimental and numerical results was achieved with Chang's continuum material model for low density foams. Parameters of the model were identified directly from the experimental stress-strain curves. Finally, continuum finite element simulations of a sandwich structure were performed and compared with experimental results. The results show the same deformation mechanism where the polystyrene layer deforms prior to alporas foam core. However, the overall response exhibits significantly higher stresses compared to experimental results.

purchase the full-text of this paper (price £20)

go to the previous paper
go to the next paper
return to the table of contents
return to the book description
purchase this book (price £65 +P&P)