A mechanical model for the onset of damage in rubber modified amorphous polymers
A mechanical model for the onset of damage in rubber modified amorphous polymers
复制标题
橡胶改性无定形聚合物损伤开始的力学模型
DOI：
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发表时间：
1996
期刊：
影响因子：
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通讯作者：
R. Schirrer
中科院分区：
文献类型：
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作者：
C. Fond;R. Schirrer
在中等加载速率下，在橡胶增韧聚合物颗粒周围的基体中，孔隙的形成通常先于塑性。许多作者提出了橡胶表面能、体积应变能和空隙生长之间关系的模型。在本文中，由于所有这些模型都不允许粒子-基质界面处的退聚，因此还必须满足另一个体积准则。采用断裂力学方法，假设基体和橡胶颗粒分别具有线性和非线性弹性，根据橡胶断裂表面能定义孔隙形成准则。在孔隙形成后，考虑基体与颗粒之间的体积守恒以及孔隙尺寸很小时由于表面张力而产生的应力，对孔隙的稳定性进行检验。观察到尺寸效应，表明在小颗粒中不能产生空洞。在微观尺度上讨论了颗粒断裂能的要求值。
At medium loading rates, void formation usually precedes plasticity in the matrix around the particles in rubber toughened polymers. Many authors have proposed models for the relationship between rubber surface energy, volume strain energy and void growth. In this paper, it is shown that another volume criterion must also be satisfied, arising from the fact that in all these models, no decohesion is allowed at the particle-matrix interface. A fracture mechanics approach, where linear and non linear elasticity are assumed for the matrix and the rubber particle respectively, is used to define a void formation criterion depending on the rubber fracture surface energy. After formation, the stability of the void is examined, taking into account the volume conservation between matrix and particle and the stress due to surface tension when the void size is very small. A size effect is observed, indicating that voids cannot grow in small particles. The required value of fracture energy in a particle on a microscopic scale is discussed.