scope:

This Bulletin contains two reports covering 3D finite element analysis of 45° lateral branch pipe models. Publication of this report - WRC Bulletin No. 344 was sponsored by the Joint Task Group on Laterals of the Subcommittee on Piping, Pumps and Valves and the Subcommittee on Reinforced Openings of the Pressure Vessel Research Committee of the Welding Research Council. This report presents the results of a three-dimensional finite element analysis of a 45 degree lateral (Model 4 of an earlier Phase I Program with geometric parameters d/D =0.5 and DIT = 40, and a stress ratio s/S = 1.0). A half symmetry model generated earlier under Phase I of the PVRC Long Range Program on Laterals was used in the present analysis. In the Phase I model, the finite element mesh consisted of 2208 eight node isoparametric solid elements. Except for the branch pipe, three or more layers of finite elements were used through the thickness of the entire model. Critical zones of the crotch regions were modeled using five elements through the thickness in the acute region and six elements in the obtuse region. As a logical extension to Phase I, an out-of-plane moment loading on the branch pipe was selected for the current evaluation. The stress indices based on the extrapolated Gaussian point stress values on the inside and outside surfaces of the selected locations are presented and compared with the results of the in-plane moment loading.