The Failure model in GeoDict is closely related to the damage models, but its approach is simpler. Instead of the continuous damage variable D, the failure model knows only two states: Failure or no failure. The material fails if the Failure Stress is exceeded, and the stiffness is degraded to 1 % of the original stiffness. The stress strain curve of an exemplary tensile experiment for an example material with a Failure Stress of 0.45 GPa looks as follows:

As soon as the defined Failure Stress is achieved, the material is considered to have failed and is no longer able to sustain any stress: the Tensile Stress in the strain stress plot is zero from that point on. Please also refer to the matrix damage example.

The volume field for the failure parameter contains a 0 for voxels without failure, and a 1 for failed voxels. However, when calculating with downsampling, or when calculating on deformed geometries, there might be also failure values between 0 and 1 resulting from a combination of several voxels.

The Failure model is available for isotropic and for transverse isotropic materials. In the isotropic case, the reference stress is the von Mises stress, and in the transverse isotropic case, the stress in the respective directions is checked.

Check the guidelines in Mazars, 1981, Alfano et al. 2001 and Michel and Suquet, 2016 for a comparison of the damage and failure models in GeoDict.