透明聚碳酸酯材料疲劳断裂行为

发布时间：2018-01-12 00:12

本文关键词：透明聚碳酸酯材料疲劳断裂行为　出处：《材料工程》2017年11期 　论文类型：期刊论文

【摘要】：研究不同应力比(R)以及退火处理对透明聚碳酸酯(PC)板材疲劳性能的影响规律与机理,并对聚碳酸酯疲劳裂纹扩展过程与机理进行分析。结果表明:退火后聚碳酸酯试样的残余应力明显变小,疲劳性能明显提高,这是由于机加工造成PC试样残余拉应力,而消除残余拉应力能够明显改善PC的疲劳性能;正应力比(拉拉疲劳)情况下,随着应力幅值变大,PC的疲劳性能明显下降,而负应力比(拉压疲劳)对PC的疲劳性能影响较为复杂。断口形貌分析表明,PC疲劳裂纹断口存在明显的裂纹源区、稳定扩展区与失稳区,而PC的疲劳裂纹扩展机理是首先在应力作用下产生银纹,当应力超过银纹中微纤维强度或在多次循环应力作用下疲劳而造成微纤维破坏时,银纹便发展为裂纹。
[Abstract]:The effects of different stress ratios (R) and annealing treatment on fatigue properties of transparent polycarbonate (PC) sheets were studied. The process and mechanism of fatigue crack growth of polycarbonate were analyzed. The results showed that the residual stress of the sample was obviously smaller and the fatigue property was improved obviously after annealing. This is due to the residual tensile stress of PC specimen caused by machining, but eliminating residual tensile stress can obviously improve the fatigue performance of PC. In the case of normal stress ratio (Lara fatigue), the fatigue performance of PC decreases obviously with the increase of stress amplitude, but the influence of negative stress ratio (tensile / compressive fatigue) on the fatigue performance of PC is more complex. The fracture morphology analysis shows that the fatigue performance of PC decreases with the increase of stress amplitude. There are obvious crack source region, stable growth zone and unstable zone on the fracture surface of PC fatigue crack, and the fatigue crack growth mechanism of PC is to produce craze at first under the action of stress. When the stress exceeds the strength of the microfiber in the craze or fatigue caused by repeated cyclic stress, the craze will develop into a crack.
【作者单位】：中国航发北京航空材料研究院;
【基金】：益材基金(YF53130808)
【分类号】：TB324
【正文快照】： ZHANG Xiao-wen,WU Nan,ZHANG Xuan,MA Li-ting,LI Lei(AECC Beijing Institute of Aeronautical Materials,Beijing 100095,China)聚碳酸酯(PC)具有很好的光学性能(2mm厚板材的透光率可达90%以上),较高的弹性模量,突出的耐冲击性能,冲击强度比聚酰胺、聚甲醛等高出3~10倍,另

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