Estimation of maximum torsional moment for multicorner tubes

In this paper, the estimation of maximum torsional moment for multicorner tubes under torsional loading was investigated using nonlinear FE analysis. The effects of tube geometries and strain-hardening coefficient on the torsional behaviour were discussed. The maximum torsional moment was due to the occurrence of sectional collapse of the tubes, and the mechanism of sectional collapse could be classified into three physical phenomena, elastic buckling, plastic yielding and plastic flattening of the cross section. Moreover, based on our numerical results, analytical solution for estimating the maximum torsional moment for each phenomenon was proposed.