Advanced Friction Parameters
If you are using the Rigid Body Analysis Method, then Advanced Friction parameters can be defined for individual slope materials. Advanced friction options include:
- Scarring
- Viscoplastic Damping
The advanced friction options in RocFall are based upon methods developed by RAMMS ROCKFALL (Bartelt et. al. 2016, Leine et. al 2013).
To define Advanced Friction parameters:
- In the Slope Material Library, select the desired material and select the Advanced Parameters button.
- You will see the Advanced Friction Parameters dialog.
- To define scarring parameters, select the Scarring Parameters check box and enter values for:
- Dynamic Friction
- Max Dynamic Friction
- Beta
- Kappa
- To define Viscoplastic Damping, select the check box and enter a Ground Drag Coefficient.
The Material Type list can be used to select a material type based on approximate material hardness. This has the effect of loading pre-defined parameter values for both the Scarring and Viscoplastic Damping options. However, note that this is just a shortcut for entering appropriate values. After you select a Material Type, you can still edit the input values as necessary. They are not fixed by the selection of a Material Type. - When you are finished defining the Advanced Friction parameters, click OK in the dialog.
The graph and the schematic image give an indication of the effect of the scarring parameters, but this should only be used as a rough guide, not as a precise indicator since actual effects will depend very much on the particular slope geometry, rock properties, and other slope parameters.
Notice that, when Advanced Friction parameters have been enabled for a material, the Advanced Parameters button will display a green check mark to indicate that advanced friction parameters are in effect for that material.
Advanced Friction Tutorial
See Tutorial 10 - Advanced Friction in RocFall for an illustration of the effects of the Advanced Friction options.
Advanced Friction Verification
See the Sliding Verification document for examples of Scarring and Viscoplastic Damping for Rigid Body analysis.