岩土各向同性损伤本构模型

Constitutive model for isotropic damage of geomaterial

基于连续介质力学基本概念得出岩土损伤复合体理论的应力–应变合成一般模式,简化得出岩土各向同性损伤复合体理论的应力–应变合成模式,建立了岩土各向同性损伤本构模型。提出了岩土各向同性损伤本构模型的数值求解法。通过对一个算例分析,加深了对岩土损伤机理的认识。计算分析认为:串联假设不适用于岩土体;严格意义上,并联假设不适用于岩土体;当应力较小时混合体的应力–应变关系与理想原状岩土类似,与重塑土差异较大,应力较大时,应力–应变关系特点与应力路径有关。

The reasonable synthetic mode of stress and strain for complex theory of geomateriai damage was obtained based on the basic concept of continuum mechanics. The simplified formulas of synthetic mode of stress and strain for isotropic damage was provided. A constitutive model for isotropic damage of geomateriais was put forward, and its numerical computation procedure was also given. The calculated results for a simple example could highlight our understanding about the mechanism of geomateriai damage, and several useful conclusions could be drawn： The series assumption could not be used to the synthetic mode of stress and strain for complex theory of geomateriai damage; strictly speaking, the parallel assumption could not be used to the synthetic mode of stress and strain even under small strain; the complex stress-strain behavior was similar to that of ideal natural geomateriais under small stress, and varied with stress path under large stress.