基于广义热力学的超固结土本构模型

基于广义热力学基本理论，通过考虑塑性剪切变形产生的能量一部分以塑性自由能的形式储存，并且该部分自由能与超固结度相关，结合修正剑桥模型的热力学函数形式建立了适用于超固结土的自由能函数和耗散函数。该耗散函数与当前应力状态无关，相关联流动法则仍然适用。由建立的耗散函数和自由能函数，推导了弹塑性本构关系的屈服函数、流动法则、硬化定律。通过4种不同超固结土的试验结果和计算结果进行比较，验证了模型的合理性。

Generalized thermodynamics based constitutive model for over-consolidated clays

The free energy and dissipation function for over consolidated clays are established, which are based on the generalized thermodynamic method and combined with the thermodynamic functions form of the modified Cam model. The energy generated by the plastic shear deformation is considered a part of free energy in the free energy function, and this partial free energy is related to the degree of over consolidation. When the degree of over consolidation decreases, the free energy generated by the plastic shear deformation also decreases. The dissipation function is independent of the current stress state, so the associated flow rule is still employed in this paper. Based on the free energy function and the dissipation function, all of the yield function, the flow law, the hardening law and the elastic law can be obtained with strict mathematical derivation from the two scalar functions. The final elastic-plastic incremental relation can then be obtained. Finally, the rationality of the model is verified by comparing the calculation and experimental results in stress and strain, volumetric strain of four different over consolidation clays.