Conversion of a circumferentially cracked pipe into a beam and prediction of fatigue crack propagation in a beam using FRANC 2D

Abstract

When pipes are subjected to different types of loading like compression, tension, internal pressure, bending or any combination of these may initiate and propagate a crack. This becomes more important if the pipes carry hazardous fluid. To predict fatigue crack propagation in circumferentially cracked pipe using its three dimensional data becomes cumbersome. In the first part of this project the pipe is converted into a beam using conformal transform. After the pipe was converted to beam it was found that the crack in the beam is not through. Hence the fatigue crack propagation cannot be simulated using FRANC2D as it is finite element based two dimensional crack propagation simulator software. In the second part of the project, the fatigue crack growth tests were carried out on an EN8 steel specimen in Instron 8800 machine. The crack propagation in EN8 steel beam was also simulated using FRANC 2D. Then the results obtained experimentally and from FRANC 2D were compared.