Geomechanics Module Updates

For users of the Geomechanics Module, COMSOL Multiphysics® version 5.6 brings plasticity and damage improvements, in situ stress, and elliptical cap improvements. Browse these geomechanics features and more below.

Plasticity Improvements

A new node, Set Variables, is available as an attribute under the Plasticity, Porous Plasticity, Soil Plasticity, Concrete, Rocks, and Elastoplastic Soil Material nodes. These new nodes make it possible to assign values or expressions to plastic variables based upon Boolean conditions, for both small-strain and large-strain plasticity.

Damage Improvements

There are several improvements to the Damage feature including a new phase-field-based damage model for crack propagation. The news includes:

  • New viscous regularization method for time-dependent analysis
  • Polynomial strain softening and Multilinear strain softening available for the damage evolution laws for Scalar damage and Mazars damage for concrete
  • New Phase field damage model, available in the Linear Elastic Material node in the Solid Mechanics interface
  • Damage feature available in the Layered Linear Elastic Material node of the Shell interface
  • Damage feature available in the Linear Elastic Material node of the Layered Shell interface
  • A new model: Brittle Fracture of a Holed Plate

Evolution of the crack phase field during loading of a holed plate.

In Situ Stress

A new option to enter In-situ stresses is available for the External Stress attribute, a subnode to the Linear Elastic Material, Nonlinear Elastic Material, and Elastoplastic Soil Material models.

The COMSOL Multiphysics version 5.6 UI with the External Stress settings shown and the in-situ stress input selected, and a triaxial test hardening soil model in the Graphics window. Demonstrating the In-situ stress option The External Stress node settings in COMSOL Multiphysics® version 5.6 with the In-situ stress option chosen.

Improvements to the Elastoplastic Soil Models

There are several improvements to the elastoplastic soil models:

  • In the Extended Barcelona Basic soil model, Poisson’s ratio is a new input, as an alternative to the shear modulus
  • The initial void ratio is added as a material input for the Modified Cam-Clay, the Modified Structured Cam-Clay, and the Extended Barcelona Basic soil models
  • For the Hardening Soil model, the input for the void ratio at reference pressure is replaced by the initial void ratio

Default Contour Plots

When using the Elastoplastic Soil Material model, the results will include default contour plots of the equivalent plastic strain, created inside stress plot groups. Additionally, a separate contour plot showing the void ratio is added.

A model in green, yellow, orange, and red that uses a default contour plot of the void ratio. An example of a default contour plot Default contour plot of void ratio in a settlement analysis.

New Tutorial Models

COMSOL Multiphysics® version 5.6 brings several new tutorial models to the Geomechanics Module.

Mechanical Modeling of Bentonite Clay

A 1D plot of void ratio, blue line, and radial stress, green line, versus suction. Bentonite clay mechanical model Evolution of the void ratio and radial stress versus suction in a uniaxial swelling test for bentonite clay.

Application Library Title:
mechanical_modeling_of_bentonite_clay
Download from the Application Gallery

Brittle Fracture of a Holed Plate

A plate model with three holes shown at four different times; a crack forms and gets larger from left to right. Holed plate model Evolution of the crack phase field during loading of a holed plate.

Application Library Title:
holed_plate_fracture
Download from the Application Gallery

Strength Reduction Method for Slope Stability

A model of a soil embankment shown as a rectangular 3D box with the left corner cut out to create a slope, with displacement shown in a rainbow color plot. Slope stability model Displacement of a soil embankment just before the slope collapses. The strength reduction technique is used to calculate the factor of safety (FOS).

Application Library Title:
strength_reduction_method
Download from the Application Gallery

Shallow Foundation on Unsaturated Soil

An unsaturated soil model with red arrows indicating load and a surface plot indicating volumetric plastic strain. Unsaturated soil model A settlement and heave analysis is performed, comparing the Modified Cam-Clay and Extended Barcelona Basic soil models. The plot shows the load (arrows), volumetric plastic strain (surface), and resulting deformation.

Application Library Title:
settlement_analysis
Download from the Application Gallery