Impulsive loading of simply supported lattice truss core sandwich beams with axial restraints

The dynamic response of a simply supported lattice truss core sandwich beam with axial restraints subjected to uniform transverse impulsive loadings was studied through rigid-plastic analytical model and elastic-plastic finite element (FE) calculation. Firstly, the maximum deflections of the sandwich beam predicted by both circumscribing and inscribing yield loci were given and compared with those predicted by finite element method. It is found that the FE predictions of the maximum deflections are between those predicted by the circumscribing and inscribing yield loci. The FE predictions of the maximum angle of rotation at the simply supported ends approach the analytical model employing the circumscribing yield locus. Then the shock resistance and energy-absorbing capability of the sandwich beam were studied. According to the FE analysis, it is indicated that the maximum deflection and plastic energy absorption of the sandwich beam are sensitive to the relative density and inclination angle of the sandwich core member, and the properly designed sandwich beams have superior energy-absorbing capability and shock resistance.