group_contactspring_friction_automatic index switch

If switch is set to -yes, the friction coefficient for contact springs will be determined from the plasticity law angle of neighbouring elements. For a neighbouring group_materi_plasti_mohrcoul the friction coefficient $f$ will be set to $f = (2./3.) {\rm tan} \phi$ with $\phi$ the friction angle in the mohr-coulomb law of the neighbouring elements. For a neighbouring group_materi_plasti_diprisco the friction coefficient $f$ will be set to a value depending on the parameter $\gamma$ of that law.

If no neigbouring elements with appropriate material law are found, then f will be set to 0.2.

The index specifies the element_group, see element_group.