基于连续介质力学有限变形理论,采用完全拉格朗日描述法导出压缩试验本构关系的大变形法表述形式.首先根据压缩试验特点建立大、小变形法应力张量和应变张量之间的转换式,得到一般意义上的大变形法压缩本构关系.然后在小变形法双曲线模型基础上,得到其对应的大变形法本构方程,并提出简化形式的大变形法双曲线模型.工程实例和参数分析的结果均表明,大变形法双曲线模型可较好地模拟土体的大变形压缩试验本构关系.大、小变形法的双曲线参数在定义和数值上均不相同,但两者服从一定的变化规律.
Based on the large-deformation theory of continuum mechanics,a novel method for describing the large-deformation constitutive relations of geomaterials based on compression test was proposed using total Lagrangian description technique.According to the characteristics of compression test,the transformation formulae of stress tensors and strain tensors between the large-deformation method and the corresponding small-deformation method were firstly derived;and the large-deformation constitutive relation(LDCR) of compression was presented with a general meaning.Then the LDCR equation for the case of a small-deformation hyperbolic model,as well as its corresponding simplified large-deformation hyperbolic model,are obtained.The results of case studies and a parametric analysis show that the proposed large-deformation hyperbolic model can well simulate the constitutive-relations of geomaterials under the large-deformation compression condition.From the viewpoint of both the physical definition and the numerical magnitude,the parameters of hyperbolic models for the large-deformation method and the small-deformation method are different but regularly obey a certain function of variation.