Torsional collapse of thin-walled prismatic columns is studied analytically
and numerically. Simple torsional collapse models are developed to predict
the collapse behavior of square columns under large plastic rotation using
energy method. By considering the combined effect of geometry and material
, the onset of the sectional plastic buckling is predicted and the critical
twisting rotation for sectional buckling is obtained. Next, an analytical
expression is derived for the moment-rotation relation valid for rotation u
p to 180 degrees. The analytical solution is shown to compare well with the
numerical results. The solutions are then extended for rectangular and hex
agonal thin-walled columns. Numerical simulations for rectangular and hexag
onal columns are also carried out and the results are presented in this pap
er for the purpose of comparison. (C) 2000 Elsevier Science Ltd. All rights
reserved.