Effects of Load and Displacement Controlled Bending on Plastic Collapse of Pressurized Pipes

AbstractAn accurate determination of the pressure to cause plastic collapse of a pipe is important when considering its structural integrity. This paper explores the way in which initial stresses, induced by either load or displacement controlled bending, influence plastic collapse as a result of internal pressure. Both open ended and closed ended pipes are considered. The effect of initial bending stresses created by far-field displacement is often considered to be similar to load controlled stresses. Using three dimensional finite element analysis it is demonstrated that global collapse pressures for load and displacement controlled conditions may be significantly different. For both pipe end conditions load controlled bending affects the plastic collapse pressure. However, displacement controlled bending has little influence