On the effect of anisotropy on the performance and simulation of shrinking tubes used as energy absorbers for railway vehicles

The standard BS EN 15227 requires accurate numerical modelling of railway vehicle energy absorbers that must be correlated against experimental data. Although thin-walled tubes can exhibit anisotropy, such models have traditionally included isotropic material properties. Thus, this work investigates whether anisotropic may increase the accuracy shrinking tube absorbers. Tensile testing extruded AW-6082 aluminium alloy showed yield strength was 10% lower in hoop direction than longitudinal direction. Further, to assess effect incorporating behaviour model, were compressed under quasi-static conditions. Numerical tubes, including (von Mises function) and (Hill’s quadratic properties, compared overestimated steady-state reaction force, even without inclusion friction, indicating do not fulfil requirements standard. Conversely, predicted a force enabled dissipation by means coefficient friction μ ​= ​0.03. these results demonstrate need include anisotropy simulation, value expected due methodology characterization model implemented.