PP-R材料在准静态加载下的断口形貌研究

Fracture Morphology of PP-R Material Under Quasi-static Loading

利用扫描电子显微镜(SEM)及宏观断口形貌法观察无规共聚聚丙烯(PP-R)试件在高周期疲劳以及准静态载荷作用下的Ⅰ型试件断面与复合型试件断面的显微组织形貌与宏观断口组织,对PP-R材料的断裂机理进行研究。结果表明:PP-R材料在准静态Ⅰ型与复合型两种准静态加载方式下,裂纹在稳定扩展区域属于韧性断裂;裂纹在高速扩展区域属于脆性断裂;疲劳裂纹预制阶段属于韧性断裂。

I-mode and mixed-mode fracture surface morphology of polypropylene random （PP-R） materials under high-cycle fatigue load and quasi-static load were observed by using SEM and macroscopic fracture morphology. The fracture mechanism of PP-R was studied. The results show that the crack of PP-R material belongs to ductile fracture in the stable expansion of the region, and belongs to brittle fracture in the high-speed extension area, and belongs to ductile fracture in prefabricated stage of fatigue crack under quasi-static loading and mixed-mode loading.