A modelling and simulation on failure prediction of ductile polymer based on craze evolution and annihilation
A modelling and simulation on failure prediction of ductile polymer based on craze evolution and annihilation
复制标题
基于银纹演化和湮灭的韧性聚合物失效预测建模与仿真
DOI：
10.1299/kikaia.70.810
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发表时间：
2004
期刊：
影响因子：
--
通讯作者：
K. Shizawa
中科院分区：
文献类型：
--
作者：
Seiichi Kobayashi;Daisuke Tomii;K. Shizawa
由于裂纹扩展导致的聚合物板的延性断裂的特征是传播颈前部的失效。在本文中，严格推导了明确表示银纹效应的弹粘塑性本构方程。通过对银纹速率函数参数的热力学讨论，提出了一种新的银纹演化方程，以银纹产生的静水应力准则来表达取向分子区与玻璃态分子边界上的银纹浓度以及取向区的银纹湮灭。此外，对于具有一些圆孔的聚合物块，对影响银纹生长的平均塑性应变的演化规律进行了数值确定。为了验证该模型，进行了有限元模拟。裂纹扩展和消失被可视化，并讨论了基于该模型进行失效预测的可能性。
Ductile fracture of a polymer plate due to craze growth is characterized by a failure in the front of propagating neck. In this paper, the elastoviscoplastic constitutive equation, that explicitly represents the effect of craze, is rigorously derived. Through a thermodynamic discussion about arguments of craze rate function, a new craze evolution equation is proposed so as to express the craze concentration on the boundary between the oriented molecular region and the glassy one, and the craze annihilation in the oriented region, with a hydrostatic stress criterion of craze generation. Additionally, an evolution law of mean plastic strain affecting the craze growth is numerically identified for a polymer block with some circular holes. A finite element simulation is carried out in order to verify this model. The craze propagation and annihilation are visualized, and the possibility of failure prediction based on this model is also discussed.