Limit analysis based on elastic compensation method of branch pipe tee connection under internal pressure and out-of-plane moment loading

A new method of calculating the limit load of a structure via a sequence of incompressible elastic finite element calculations with variable Young's m oduli converging to the rigid perfectly plastic problem is used to study th e limit load of branch pipe tee connections. Several models of branch pipe tee connection are meshed with shell elements and submitted to internal pre ssure with end axial load effect or out-of-plane moment. Results are compar ed with lower and upper bound analytical solutions and experimental results reported in the literature. Computations with 20 noded cubic elements are also proposed to validate shell studies. The J integral is also calculated by a simplified method with the limit load, using an example of a defective branch pipe tee connection. (C) 1998 Elsevier Science Ltd. AU rights reser ved.