摘要
采用2种本构行为对聚甲基丙烯酸甲酯(PMMA)刮擦变形进行有限元模拟。结果表明,对PMMA而言,在模拟过程中若忽略屈服点后的热软化现象,则会导致刮擦模拟结果与实验结果产生较大偏差。但同时也发现,若在模拟时采用高速压缩测试获得的结果对PMMA刮擦过程中屈服点后的热软化进行描述,会导致刮擦模拟结果与实验结果产生更大的偏差。进一步分析表明,这是由于常规高速压缩测试过程中的温度上升幅度远大于刮擦形变所导致的。高速压缩测试需要采用厚度为0.06~0.10 mm的PMMA样品,其获得的结果才能实现更为准确的刮擦模拟。但当前的高速压缩测试技术只能使用较厚的样品(毫米级)进行测试,使用更薄的样品尚不具有可行性。
Two constitutive behaviors were used to simulate the scratch deformation of polymethyl methacrylate(PMMA)in finite element modeling.It is demonstrated that ignoring post-yield heat softening in simulation can result in a considerable discrepancy between scratch modeling results and experimental results for amorphous polymers with relative low Tg,e.g.,polymethyl methacrylate(PMMA).However,it is also discovered that an even larger discrepancy between scratch modeling results and experimental results occurs if the post-yield heat softening behavior during scratch modeling is described by constitutive behaviors obtained through the high speed compression test.A deeper analysis reveal that this unexpected result is caused by a much larger temperature rise during the high speed compression test than that during scratch-induced deformation.To realize more accurate scratch modeling on PMMA,the thickness of samples used in the high speed compression test should be between 0.06 mm to 0.10 mm.However,currently high speed compression tests can only be conducted with thicker samples due to technical limitations,and it is not feasible to use thinner samples.
出处
《高分子材料科学与工程》
EI
CAS
CSCD
北大核心
2021年第2期89-95,共7页
Polymer Materials Science & Engineering
基金
国家自然科学基金资助项目(51420105004,51721091)
四川省市场监督管理局科技计划(高分子材料刮擦性能测试技术及标准化研究)。
关键词
聚甲基丙烯酸甲酯
表面
刮擦
塑性形变
有限元模拟
polymethyl methacrylate
surface
scratch
plastic deformation
finite element modelling
