基于次加载面摩擦模型的接触面剪切特性研究

Shear characteristics of interface based on subloading-friction model

为了反映土与结构接触面的应变软化特性以及剪切速率对土与结构接触面力学特性的影响,基于ABAQUS软件提供的FRIC子程序,采用显式积分算法,对能够表现接触面上应变软化的次加载面摩擦模型进行二次开发.利用该模型模拟土与结构接触面的直剪试验,研究直剪试验过程中次加载面摩擦模型接触面上的应力演变过程.研究结果表明,利用次加载面摩擦本构模型,能够较好地模拟土-结构接触面直剪试验中的应变软化和密实状态的类砂土残余切应力随剪切速率的增大而下降的现象.在剪切位移的发展过程中,次加载面摩擦模型接触面上的切应力先增加后减小,接触面远离加载端一侧到另一侧的应力发挥水平先后达到最大值.该研究表明,次加载面摩擦模型可以用于土与结构接触面的应变软化特性和速率相关性的模拟.

A secondary development of the subloading-friction model that can describe the strain softening phenomenon of contact surface was realized based on subroutine FRIC provided by ABAQUS by using explicit integration algorithm in order to reflect the strain softening characteristics of soil-structure surface and the effect of shear rate on the mechanical properties of soil-structure interface.The developed model was used to simulate the direct shear tests of soil-structure interface,and the evolution process of the stress on the contact surface during direct shear test was analyzed.The numerical calculation results indicate that the subloading-friction model can simulate the strain softening phenomenon of soil-structure interface well,and simulate the decrease of residual shear stress of dense quasi-sands with the increase of shear rate in the direct shear test.The shear stress on the contact surface of subloading-friction model increases at first and then decreases with the development of shear displacement,and the stress exertion level of the contact surface reaches the maximum successively from one side away from the loaded end to the other side.Results show that the subloading-friction model can be used to simulate the strain softening characteristics and rate dependence of the mechanical properties of soil-structure interface.