Plastic limit loads of defective pipes under combined internal pressure and axial tension

In this paper, a finite element mathematical programming formulation is presented for the statical limit analysis of 3-D perfectly plastic structures. A direct iterative algorithm is employed in solving the above optimization formulation. The numerical procedure has been applied to carry out the plastic collapse analysis of defective pipes under combined internal pressure and axial tension. The engineering situation considered has a practical importance in the pipeline industry. The effects of four kinds of typical part-through slots on the collapse loads of pipes are investigated and evaluated.