高应变率下弹道明胶的本构模型研究

为了更好地进行枪弹和破片终点效应的数值模拟工作，综述了弹道明胶物理性质的实验研究现状；分析了应变率相关超弹性本构模型和流体弹塑性本构模型的特点，结合相关实验数据推导得到了弹道明胶的状态方程系数；进行了球形杀伤元高速侵彻弹道明胶的实验，并建立了对应的有限元模型；两种不同本构模型得到的数值结果与实验数据的对比表明，在高应变率下流体弹塑性本构模型能更好地模拟弹道明胶响应。弹道明胶虽然是一种应变率敏感材料，但在高应变率下由高压导致的材料可压缩性占主导，其物理响应可以用一定形式的动载本构关系（流体弹塑性本构）予以近似。

Study of Constitutive Model of Ballistic Gelatin at High Strain Rate

In order to numerically simulate the terminal effect of bullet and fragment, the research status of ballistic gelatin physical properties is summarized firstly. The features of rate-dependent hyperelastic model and elastic-plastic hydrodynamic model are studied, respectively. The coefficients of equation of state of ballistic gelatin are concluded based on related experiments. The penetration of a steel sphere into a block of ballistic gelatin is studied experimentally, and is modeled using the finite element method. The comparison of the computed and experimental results shows that the elastic-plastic hydrodynamic model can simulate the experiment more accurately at high velocity impact. Ballistic gelatin is known as a rate-dependent sensitively material, but the thermal softening is dominant at high strain rate, the physical behavior can be modeled with a dynamical constitutive.