THE STUDY OF TOUGHNESS FOR FIBER COMPOSITE PE PIPES

Since new fiber composite polyethylene (PE) materials are contemplated for use by gas industry, a major challenge is to perform a computational analysis for the cracked and uncracked pipes. This is accomplished using a unique finite element code PFRAC. The initial development of the PFRAC model was for isotropic pipe materials. The modifications described here detail a recent enhancement to consider the anisotropic pipe material, to simulate and analyze the dynamic and laminate situations for the fiber composite PE material gas pipelines. According to the test data of material constituents, several numerical examples are given to illustrate the performance of the fiber PE pipes. Compared with pure PE pipe, the hoop displacements are decreased from 53% for pipes with random short fibers to 5% for pipes with fibres wound at 80 degrees to the pipe axes; the crack driving forces are also decreased from 50% to 17%, respectively.