高聚物粘结炸药蠕变行为的近场动力学模拟方法

摘要

近场动力学是一种新的无网格方法,发展了其对材料粘弹性力学行为的分析能力.采用Burgers粘弹性模型,结合非线性粘弹体的时间-应力等效原理,推导出非线性粘弹体在不同应力下的蠕变柔度的表达式和近场动力学蠕变本构力函数,建立起可应用于高聚物粘结炸药的近场动力学蠕变模拟方法.模拟了PBX9502的蠕变行为,并通过实验验证.建立的方法可用于高聚物粘结炸药在温度和应力共同作用下的蠕变行为分析.%Peridynamics is a recently developed meshfree method with many aspects needing to be further studied, such as viscoelasticity, plasticity and the coupling of elasticity, plasticity and viscosity.The analytical ability for considering viscoelastic behavior of peridynamics is developed.The theoretical basis, modeling procedure and numerical scheme of peridynamics are first reviewed.Then the expressions of creep compliance under different stresses and the peridynamic creep response functions are deduced combing time-stress equivalence principle of nonlinear viscoelastic materials and utilizing Burgers viscoelastic model.In this manner, the peridynamic creep simulation method which can be applied to polymer bonded explosives is established.The creep behavior of PBX9502 is then simulated using this method, which indicates a good conformity with experiment results.The established method can be applied to analyze creep behavior of polymer bonded explosives under different temperatures and different stresses.