基于粗粒珠簧模型,采用分子动力学模拟了玻璃态高聚物在不同应变率下微空洞的产生、扩展及断裂演化过程,表明银纹产生的微空洞会引起周围的应力集中,微空洞迅速扩展并伴有少量合并;结合临界应力判据,给出了银纹萌生的微观构型;通过引入非仿射位移场并结合应力-应变响应关系,计算了参与率随应变的演化,证实了聚合物在银纹化破坏过程中具有应变率相关敏感性的线性粘弹性特征。与实验现象吻合较好。
By use of coarse-grained bead-spring models and molecular dynamic simulations, the initialization,propagation of voids and crazing,and fracture of fibres in glassy polymers were modeled under different strain rates,Which confirmed that the micro-voids produced by crazing can cause the stress concentration,and the micro-voids was expanded rapidly and accompany with a small amount of combination.The initiation of micro-crazing configuration was given according to critical stress criterion.By introducing a non-affine displacements and combined with the response relation of stress-strain,we had calculated the evolution of participation rates with the strain,the linear viscoelasticity of polymers with strain rate sensitivity was confirmed by our modeling.
参考文献
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