国产航空有机玻璃(PMMA)的压缩应力-应变行为研究——Ⅱ.力学性能特征参数分析

A STUDY OF UNIAXIAL-COMPRESSIVE STRESS-STRAIN BEHAVIOUR OF POLYMER PMMA Ⅱ. Analyses on the Characteristic Parameters of Mechanic Properties

讨论从加卸载循环的应力-应变表征曲线提取得到的各材料力学性能,尤其是关于屈服和塑性变形的特征参数。包括加卸载弹性模量E_L^T,E_u^T;屈服点的表征参数:屈服应力σ_s^T,屈服应变ε_s^N,屈服应变能U_s;热激活塑性变形的表征参数:活化体积V_τ和活化能ΔH。讨论这些参数对温度和应变率的依赖关系,寻求由这些特征参数作表述,或是存在于这些参数之间的经验关系或规律。

Discusses the characteristic parameters of material mechanical properties, especially for the yielding and plastic deformation, which can be obtained from more than 40 group's stress-strain curves of loading-and-unloading circulating presented in our works. The detailed contents include the elastic moduli of loading and unloading E_L^T, E_u^T, the characteristic parameters of yielding point: yielding stress σ_s^T, yielding strain ε_s^N and yielding strain energy U_s, and the characteristic parameters of thermalactivated plastic deformation: activation volume V_τ and activation energy ΔH. Discusses the relations of these parameters to the temperature T and strain rate lg ε_l^N, analyse the empirical relationships and rules described by these parameters in order to establish the corresponding model of constitutive theory