Stress analysis with combined mechanical and thermal effects for pipe tees using the finite element method (Thermoelastic)

The stress state for various pipe tees under combined thermal and mechanical loading is analyzed using a Finite Element Analysis (FEA).; The state of stress of piping components is of great importance in the applications of piping systems necessary in the processing and transport of fluids. Failure in these systems often occurs at tee branches due to the stress intensification in these areas. The various piping codes address this problem by using stress intensification factors (SIF). The SIFs are calculated by dividing the peak stress in the tee by the nominal axial stress in the wall of the pipe tee caused by the applied bending moment. These SIN used in the piping codes were experimentally determined in the 1950's for a 4 x 4 Schedule 40 tee. These empirical results were extrapolated for use on all sizes of tees.; The research presented here investigates the stress states produced for loaded branch tees at various temperatures using Finite Element Analysis. Tees of different geometries are analyzed. The temperature dependent material properties and method of loading of the pipe tee is addressed. The stress intensification factor is calculated and compared to the code values and previous experimental data.; Although the in-plane SIF determined by the FEA were found to be consistent with the experimental and ANSI B31 code formulations, the out of plane SIF determined by FEA were higher. The results indicate that the SIF is only minimally dependent on thermal loading with various geometries.