INELASTIC TORSIONAL BUCKLING STRENGTHS OF CRUCIFORM COLUMNS

A theoretical study of the torsional buckling strengths of cruciform c olumns is presented. The influences of both initial geometric imperfec tions and residual stresses are investigated. A nonlinear elastic tors ion theory based on simple beam-column theory is presented and used to predict the torsional behaviour up to first yield. For the behaviour beyond the first yield, a nonlinear finite element model is developed which is able to make a complete inelastic load-twist analysis. it is found that both initial twists and residual stresses can significantly reduce the ultimate torsional buckling strengths of cruciform columns .