论文部分内容阅读
基于临界状态土力学框架,建立了一个适用于往返循环荷载作用的砂土次加载面本构模型。模型采用无弹性域假设,认为土体受到反向荷载的瞬时就产生塑性变形,砂土的弹性区域退化为一个点。根据试验结果,屈服面采用倒子弹头型。由于砂土的孔隙比与固结压力不存在唯一的关系,这样使得屈服面大小与孔隙比不能直接耦合,因而硬化规律不是剑桥模型的体变硬化,而是采用增量形式的塑性偏应变硬化表达式。流动法则采用加入状态参数概念的修正的Rowe应力剪胀关系。该模型能考虑砂土变形特性对密度和固结压力的双重依赖型,能合理地模拟砂土动荷载下的应力-应变关系曲线的光滑性、变形积累性、滞洄性。
Based on the critical mechanics framework of soil mechanics, a constitutive model of subloading surface of sand is established, which is suitable for cyclic loading. The model uses the assumption of inelastic domain, that plastic deformation occurs when the soil is under reverse load, and the elastic region of sand is degraded to a point. According to the test results, the yield surface using bullet-type. As the void ratio of sand and consolidation pressure does not exist a unique relationship, so that the yield surface size and porosity can not be directly coupled, so the hardening law is not the Cambridge hardening of the body model, but the incremental form of plastic partial strain hardening expression. The law of flow uses a modified Rowe stress-dilatancy relationship that incorporates the notion of state parameters. The model can consider the dual dependence of the deformation characteristics of sand and sand on the density and consolidation pressure, and can reasonably simulate the smoothness, deformation accumulation and stagnation of the stress-strain curve under dynamic sand loading.