Time-space damage analysis of the short fiber reinforced thermoplastics during creep and fatigue loading

有效地设计和制造用于工程应用的塑料的能力需要大量关于材料的长期性能的知识。疲劳寿命是一种典型的长期特性，应在经历循环载荷的部件和结构中进行表征。人们对塑料疲劳的基本机理进行了大量的研究，但对许多塑料的疲劳机理还不是很清楚。本研究采用声发射(AE)、超声测量和光学显微镜(OM)技术对玻璃纤维增强尼龙66的疲劳断裂机理进行了研究。循环加载使试件边缘的声速降低。这种行为与试件边缘的基质裂纹和纤维断裂有关。

The ability to effectively design and manufacture plastics for engineering applications requires a large body of knowledge on long-term performance of the materials. The fatigue life is a typical long-term property that should be characterized in components and structures where cyclic loads are experienced. There has been considerable research into the basic mechanism that cause fatigue of plastics, but still there is not a clear understanding of the mechanism in many plastics. In this study, the mechanism of the fatigue fracture of glass fiber reinforced nylon66 has been identified using acoustic emission (AE), ultrasonic measurement and optical microscopy (OM) techniques. The acoustic velocity of the edge of specimens decreased by the cyclic loading. This behavior was correlated to matrix cracks and fiber breakages at the edge of the specimens.