纤维增强PE材料增韧效果的研究

以聚乙烯(PE)材料为基体，应用玻璃纤维随机或定向分布，增加材料的强度、刚度和断裂韧性，是发展高压大口径复合材料天然气管道的需要。本文基于PFRAC程序的动态断裂分析能力1]，增加了各向异性材料的本构条件，发展了对纤维增强复合材料未开裂和开裂管道的计算功能。由力学性能的试验结果，提供了材料的本构关系，对未开裂和开裂的管道进行了计算分析。结果表明，PE管道经纤维增强之后，与纯PE材料的管道相比，其环向位移下降到53%(纤维随机分布)~5%(纤维沿管道轴向80度分布)；裂纹驱动力相应下降到50%~17%，充分反映了纤维对PE材料的增强和增韧效果。

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.