Boom黏土热-力耦合弹塑性损伤模型研究

A thermo-mechanical coupled elastoplastic damage model for Boom clay

黏土的热-力耦合本构模型研究在许多工程领域,尤其是核废料地下处置方面有着十分重要的工程意义。根据Boom黏土的在不同温度下的三轴与固结试验的结果,综合考虑了温度对黏土的强度与弹性模量的影响,在Drucker-Prager(简称D-P)帽盖模型的基础上,引入了硬化方程和热损伤、力学损伤的演化方程,建立了适用于黏土的热-力耦合弹塑性损伤本构模型。将模型在ABAQUS中进行了二次开发,根据试验结果反演得到了Boom黏土的模型参数。利用所建立的本构模型,对比利时HADES试验室中的ATLAS III现场试验进行了数值仿真,计算结果表明,模型的计算结果与现场实测的结果能较好地吻合,证明了模型的合理性。

Study of the coupled thermo-mechanical constitutive model of clays is an important issue in several specific fields, especially in the analysis of nuclear waste isolation. Based on the results of undrained triaxial tests on Boom clay at different temperatures, a coupled thermo-mechanical elastoplastic damage model is established. The yield surface is based on that of the Drucker-Prager cap model. A hardening law and a thermal/mechanical damage evolution equation are presented. The developed model is implemented into ABAQUS finite element code through subroutine USDFLD. Model parameters of Boom clay are then calibrated from experimental results by back analysis. Three dimensional coupled THM modeling of ATLAS III in-situ heating tests in HADES at the HADES underground research facility is performed by the proposed constitutive model. The numerical results are in agreement with in situ measurements, demonstrating that the model can reasonably depict the main features of thermo-mechanical behaviors of Boom clay.