| 摘要 |
PROBLEM TO BE SOLVED: To provide a simple and accurate stress evaluation method of a piping structure for a so-called station piping which branches from a main pipe laid underground and has a plurality of inflection points on the ground. SOLUTION: Assuming that a vertical directional displacementδat an end of a branch pipe 9c is sum of a displacementδ1 caused by in-vertical-plane moment acting on the branch pipe 9c, a displacementδ2 caused by torsional deformation of a branch pipe 9b, and a displacementδ3 caused by bending moment of a branch pipe 9a toward the branch pipe 9b, a stress evaluation method of a piping structure evaluates a maximum stressσarising in a piping structure using a following expression (10): the expression (10) is as follows:σ=ä3EGd<SB>o</SB>(2a+2b+c)δ}/äcG(12a<SP>2</SP>+12ab+4bc+10ca+c<SP>2</SP>)+3bc<SP>2</SP>E}, where a, b, c are length of the branch pipes 9a, 9b, 9c respectively, E is a vertical elastic coefficient, G is a horizontal elastic coefficient, d<SB>o</SB>is an outer diameter of the branch pipe,δis a vertical directional displacement relative to the main pipe at a support part. COPYRIGHT: (C)2011,JPO&INPIT |
