PERHITUNGAN FAKTOR INTENSITAS TEGANGAN RETAK PERMUKAAN PADA DINDING LUAR PIPA PROFIL SCHEDULE 30 DAN 100 AKIBAT TEKANAN EKSTERNAL

Abstract

Devanka Adib Baihaqi. 102217067. Calculation of the Intensity Factor of Surface Cracking Stress on the Outer Wall of the Pipe Schedule 30 and 100 Profile Due to External Pressure Using Finite Element Method. Pipes are used in the oil and gas industry as a substitute for conventional fluid transportation to become more efficient. One of the factors that cause pipe failure is external pressure which can cause cracks in the pipe. This study is about calculating the stress intensity factor as a parameter for crack propagation on the outer wall of the pipe due to external loads. The aims of this study were (1) to determine the effect of variations in the a/c value on the stress intensity factor on the outer wall crack of the pipe due to external pressure loads. (2) Determine the effect of the Inclination Angle (α) on the stress intensity factor on the outer wall crack of the pipe due to external pressure loads. (3) Determine the effect of pipe wall thickness (t) on the stress intensity factor on the outer wall crack of the pipe due to external pressure loads. (4) Determine which variation has the most influence on the surface crack stress intensity factor on the outer wall of the pipe due to external pressure. In this study, the ANSYS® Workbench 2020 software using the Finite Element Method was used. The pipe specimen used is a 14 in pipe with 2 thickness profiles and pipe diameters based on the API 5L standard. The results showed that the largest SIF occurred in pipes with a sch 30 profile with a/t= 0.2 and a/c=0.5. Meanwhile, the smallest SIF value occurs in pipes with a sch 100 profile with a/t=0.1 and a/c=1. So besides the pipe wall thickness, the a/c value affects the SIFs results obtained. Where when the a/c value gets smaller, the SIF value obtained will be even greater. With a percentage of 0.8 to 1% between the variations. The crack angle also affects the value of the resulting opening, shear and tear modes. Keywords : Pipe, Crack, Stress Intensity Factor, External Pressure, Finite Element Method.