蠕变载荷下有机玻璃银纹萌生及损伤研究

摘要

A series of creep experiments are carried out for MDYB-3 PMMA under different stresses at the room temperature. The whole process from the crazing initiation and growth lo specimens fracture under creep is researched, finding out that the crazing in PMMA present the alternating distribution of sparse and dense ,which is perpendicular to the load. Based on the experimental data and a-nalysis, a relationship between stress and the time of the crazing initiation is given, which quantifies the crazing initiation time shortened non-linear as the stress increases. And a model is built to describe the crazing damage density with stress and time for MDYB-3 PMMA using of non-linear fitting based on hyperbolic function.%对MDYB-3航空有机玻璃开展了常温蠕变实验,研究了在蠕变载荷作用下有机玻璃银纹萌生、扩展及蠕变失效过程,发现了有机玻璃银纹沿垂直于载荷方向呈现稀疏稠密交替分布的特征.基于实验数据和图像处理与分析,提出了银纹萌生的应力-时间准则,量化了随着应力水平提高,银纹萌生时间的非线性缩短;通过研究银纹损伤密度变化,运用双曲线函数进行非线性拟合,建立了MDYB -3有机玻璃蠕变载荷下银纹损伤随时间和应力的演化规律.