地质材料弹塑性本构关系的塑性势理论

On the Plastic Potential Theory of Elasto-plastic Constitutive Relation for Geomaterials

介绍塑性势理论的由来、发展和现状。地质材料全过程应力-应变曲线在峰值前后具有不同的稳定状态,因此其弹塑性本构关系必须在应变空间中表述。给出基于塑性势理论在应变空间和应力空间中的地质材料本构关系,并讨论弹塑性耦合理论。当前在有限元位移法分析中,常用的塑性势理论本构关系式是应变空间表述的实用形式。弹塑性耦合理论较为严密和完善,但地质材料刚度劣化参数还需更多的实验数据支持。

The origin, development and status of plastic potential theory are reviewed. During two ranges before and after the peak of the complete stress-strain curve for geomaterial, the material stabilities are different, so, the constitutive relation should be expressed in strain space. The constitutive equations of the plastic potential theory expressed in strain space and in stress space are presented. The elasto-plastic coupling theory for geomaterial is also discussed. The constitutive equation of plastic potential theory is commonly used for finite element displacement method, and is a practical formulation expressed in strain space. The elasto-plastic coupling theory is rigorous and self-contained, but parameters of the stiffness deterioration for geomaterial need more experimental data.