Isotropic Phase Field Softening Material
Constitutive Law
This material is underdevelopment and only available in OSParticulas. More details will follow when done.
Material Properties
The isotropic variational mechanics model using a single energy release rate that scales evolution of damage. The critical energy release rate is enter using the base material JIc property. The other needed material properties are as follows:
| Property | Description | Units | Default |
|---|---|---|---|
| (Isotropic Properties) | Enter all properties needed to define the underlying isotropic material response | varies | varies |
| ell | Length scale parameter used in variational fracture mechanics | length units | none |
| viscosity | Viscosity to use when solving coupled phase field evolution in a diffusion tasks | viscosity units | none |
| gd | Softening law with options 0 = quadratic, 1 = exponential, 2 = linear softening | none | 0 |
| garg | An optional argument for use within the softening law. If not provided, default values depend on gd and are 1, 3, and 4, for gd = 0, 1, or 2, respectively | none | varies |
| stability | A stability factor thought to stabilize post-failure analysis | none | 0 |
| partition | Chose the method used to partition energy into energy that causes fracture and energy that does not cause fracture. The options are 0 = using eigenstrain analysis and 1 = divide into pressure and deviatoric strains | none | 1 |
| (other) | Properties common to all materials | varies | varies |
History Variables
This material stores several history variables that track the extent of the damage and evolution of the phase field:
- Maximum energy history term that provides source terms for phase field evolution
- Damage state equation to 0 if not failed and 1 if failure (i.e., phase value has reached 1)
- Current phase field value
- Change in phase field since the last time step. It is used in constitutive law modeled and is scaled by 0.5 when using USAVG method.