典型PBX基于Boltzmann函数的准静态单轴拉压非线性本构模型（英文）

A Uniaxial Nonlinear Tension-Compression Constitutive Model Based on Boltzmann Function for Typical PBXs under Quasi-Static Loading

准静态载荷下的拉伸压缩试验中,几乎所有高聚物粘结炸药(PBX)都体现出了明显的非线性本构行为,现常用的本构模型在描述这种非线性时适应性不甚理想。针对五种典型PBX炸药(PBX-X,PBX-9502,LX-17,PBX-9501,EDC-37)应力应变曲线的非线性及非对称性,基于Boltzmann函数推导了一种拉伸和压缩一起考虑的准静态单轴非线性四参数本构模型。在讨论模型待定参数物理意义的基础上,基于文中提出的待定参数初值确定方法,采用该本构模型对五种典型PBX的应力应变曲线进行了拟合。结果表明,该本构模型可较好地描述五种典型PBX炸药不同温度和应变率下的本构行为。基于Boltzmann函数的拉压非线性本构模型,有望作为一种适用于不同PBX的通用准静态本构模型广泛运用。

Abstract： In the tension and compression tests under quasi-static loading, almost all polymer bonded explosives （PBXs） reflect obviously nonlinear constitutive behavior, now commonly used constitutive model in the description of the nonlinear adaptability is not ideal. Aimming at the nonlineari- ty and asymmetry of stress-strain curves for five typical PBXs （PBX-X, PBX-9502, LX-17, PBX-9501, and EDC-37）, a quasi-static constitutive model with four parameters that considers both tension and compression was deduced based on Bo[tzmann function. Based on the discussion of the physical meaning of undetermined parameters for the model, on account of determined method of undetermined parameters proposed in this paper, the stress- strain curves for five kinds of typpical PBXs were fitted by the constitutive model. Results show that the constitutive model can well describe the con- stitutive behavior at different temperatures and strain rates for typpical PBXs. The constitutive model of tension and compression based on the Boltz- mann function is expected to be widely used as a universal quasi-static constitutive model for different PBX materials.