Combined effect of imperfections on ultimate strength of cracked plates under uniaxial compression

A series of nonlinear finite element analyses were carried out for varying levels of initial deflections, welding residual stresses as well as the length and location of cracks to investigate their combined effects on the ultimate strength of intact and cracked steel plates. The effects of plate slenderness are also considered. Based on numerical results, it is found out that when the three factors are included in the plate together, they will have combined effect on the ultimate strength of the plate rather than a simple superposition of their influences. The meaningful phenomenon is revealed that cracks will change the effect of residual stress on the ultimate strength, depending on the crack's location and length. The crack's breaking effect on residual stress are discussed for three typical crack locations and different crack lengths in the paper. The breaking effect will reduce the effect of residual stress where crack is located.