Composite energy-absorbing structures combining thin-walled metal and honeycomb structures

Abstract

The energy-absorbing structure of a crashworthy railway vehicle was designed by combining the characteristics of thin-walled metal structures and aluminum honeycomb structures: finite element models of collisions involving energy-absorbing structures were built in ANSYS/LS-DYNA. In these models, the thin-walled metal structure was modeled as a plastic kinematic hardening material, and the honeycomb structure was modeled as an equivalent solid model with orthotropic–anisotropic mechanical properties. The analysis showed that the safe velocity standard for rail vehicle collisions was improved from 25 km/h to 45 km/h by using a combined energy-absorbing structure; its energy absorption exceeded the sum of the energy absorbed by the thin-walled metal structure and honeycomb structure when loaded separately, because of the interaction effects of thin-walled metal structure and aluminum honeycomb structure. For an aluminum honeycomb to the same specification, the composite structure showed the highest SEA when using a thin-walled metal structure composed of bi-grooved tubes, followed by that using single-groove tubes: that with a straight-walled structure had the lowest SEA.