岩土力学模块附带了标准的非线性材料模型，通过 von Mises 应力和 Tresca 准则来描述金属塑性。但是，岩土力学模块的本质是土壤、混凝土和岩石等材料的非线性材料模型，这些模型内置在固体力学物理接口中。
除了预定义的内置塑性模型之外，您还可以创建自定义的屈服函数。可以通过编辑岩土力学模块中的物理接口直接创建，也可以通过 COMSOL Multiphysics 中提供的多功能方程定义物理接口创建。不需要用户编写子程序，因为您只需在这些接口中的相应编辑区域内输入本构方程即可。这些方程可以包括场变量、应力与应变不变量和派生变量的数学表达式。如果您的材料模型依赖于另一个变量（例如温度场或水压），您可以直接将它纳入到这些材料定义中。通过这种方式，可以对岩土力学模块提供的材料模型进行修正，并扩展到更一般的材料。
岩土力学模块可以方便地与 COMSOL 模块套件中其他模块的分析及其描述变量组合。特别是包括地下水流动模块中描述多孔介质流动、多孔弹性和溶质传递的物理接口。
Concrete Beam with Reinforcement Bars
Concrete structures almost always contain reinforcements in the shape of steel bars ("rebars"). In COMSOL, individual rebars can be modeled by adding a Truss interface to the Solid interface used for the concrete. The solid mesh for the concrete and the rebar mesh can be independent, since the displacements are mapped from within the solids onto ...
This deep excavation model is inspired by a benchmark exercise specified by a working group of the German Society for Geotechnics. In this model, a 20 m excavation is modeled with ten steps by means of a parametric sweep. The interaction between the soil and the retaining wall is modeled with contact pairs, and struts are activated as the ...
This model provides an estimation of the behavior of the soil during a tunnel excavation. The surface settlement and the width of the plastic region around the tunnel are important parameters needed to predict the reinforcements to use during the excavation. Two study steps are used. The first computes the stress state of the soil before ...
The triaxial test is one of the most common tests used in laboratory soil testing. The soil sample is normally placed inside a rubber membrane and then compressed maintaining a radial pressure. In this model, a vertical displacement and a confinement pressure are applied on the sample and the static response and the collapse load for various ...
Flexible and Smooth Strip Footing on a Stratum of Clay
A common verification model for geotechnical problems is of a shallow stratum layer of clay. In this model, a vertical load is applied to the clay strata top surface and the static response and collapse load are studied. The clay is modeled as an elastic-perfectly plastic material and the Mohr-Coulomb yield condition under plane strain ...
This model shows how to set up a uniaxial compression test on a prestressed soil sample. Due to uniaxial compression and simple initial stress values, it is possible to determine the vertical yield stress analytically. The soil sample is modeled with soil plasticity and the Mohr-Coulomb criterion.
Isotropic Compression Using Cam-Clay Model
Isotropic compression is a common exercise in soil testing. The modified Cam-Clay model describes the relation between the void ratio and the logarithm of the pressure. In this example, a soil sample is placed inside cylinder 10 cm in diameter and 10 cm in height. Due to the symmetry, the model is solved in 2D axial symmetry. A boundary load ...