【摘要】 研究了颗粒增强聚合物复合材料的力学行为,研究得知:材料屈服、裂纹形核、扩展与贯通直至最终断裂是一逐渐劣化过程,而损伤理论正是这一劣化过程的良好描述.通过假设自由能和耗散势函数,导出了损伤演化规律,与实验比较,模型和试验结果基本符合.进一步采用改进的Dugdale模型,重点研究损伤对GB/PPO复合材料宏观裂纹起裂的影响,通过建立损伤模型来描述材料的劣化行为和裂纹扩展,结果表明,损伤区域严重影响裂尖的性能,材料损伤对宏观裂纹起裂影响不可忽略.更多还原

【Abstract】 Damage mechanism plays an important role in governing the post yielding mechanical properties of these materials.Mechanical behaviour of micro-particle reinforced polymer composites(MPRPC) was investigated.The damage evolution rule was derived after the free energy and dissipating potential were hypothesized.The numerical prediction and the experiment measurement are in good agreement with the damage development.Furthermore,a damage modelling technique,in which the effect of damage and predicting the cracking phenomenon of a glass-bead-filled polyphenylene oxide(GB/PPO) composite are characterized,is presented using update Dugdale model.The results demonstrate that the damage zone has a considerable effect on the behaviour of crack tip zone.更多还原