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亚塑性理论是一个相对较新的本构理论框架,适合于模拟土体等具有强烈非线性特性的颗粒材料。针对Gudehus和Bauer建立的一个亚塑性模型,建议了一个修正模型。原始模型虽能定性地反映粗粒土的剪胀性和应变软化特性随土体初始密实度和应力水平变化的规律,但模型对粗粒土应力–应变关系的定量预测还不能达到令人满意的程度。在Gudehus-Bauer模型基础上,通过在本构方程中增加一个随剪应力水平变化的因子来修正张量函数的结构,增强了模型描述各种应力路径的能力。修正模型还采用了应力变换的方法来改善对粗粒土在三维应力条件下力学响应的模拟质量。论文中给出的数值结果表明,修正后的模型不仅能定性地反映粗粒土的力学响应,还能在很宽广的密实度和应力范围内得到和实验数据相一致的定量预测。
The theory of sub-plasticity is a relatively new constitutive theory framework suitable for modeling granular materials with strong nonlinear characteristics such as soil. A modified model is proposed for a sub-plastic model developed by Gudehus and Bauer. Although the original model can qualitatively reflect the law of dilatancy and strain softening of coarse grained soil with the initial density and stress level of the soil, the quantitative prediction of the stress-strain relationship of the coarse grained soil with the model can not reach satisfactory Degree. Based on the Gudehus-Bauer model, the structure of the tensor function is modified by adding a factor that varies with the level of shear stress in the constitutive equation, which enhances the ability of the model to describe various stress paths. The modified model also uses a stress transformation method to improve the simulated mass of the coarse grained soil under three-dimensional stress conditions. The numerical results given in the paper show that the modified model can not only qualitatively reflect the mechanical response of coarse grained soil, but also obtain the quantitative prediction consistent with the experimental data over a wide range of compaction and stress ranges.