tangential model history/tempdep

Purpose

This tangential model is equivalent to the tangential model history but can vary its coefficient of friction with temperature

Syntax

tangential history/tempdep

zero or more keyword/value pairs may be appended to the end (after all models are specified)

Associated material properties

Material properties

youngsModulus ( $Y$ ): The Youngs Modulus of a material, i.e. its stiffness [pressure]
poissonsRatio ( $\nu$ ): The Poisson’s ratio, i.e. the ratio of transverse to axial strain [ $\cdot$ ]

Material interaction properties

coefficientRestitution ( $e$ ): The coefficient of restitution of two materials [ $\cdot$ ]
coefficientFriction ( $\mu_0$ ): The coefficient of friction acting between two materials [ $\cdot$ ]

Global scalars

LUTfriction ( $f_\mu$ ): The temperature dependent addition to the coefficient of friction (can be a file) [ $\cdot$ ]

Description

This model can be used in the tangential argument of both particle_contact_model and wall_contact_model.

The main difference is, that the coefficient of friction is modified by a temperature dependent function. In detail the coefficient of friction is given as

$\mu = \mu_0 + f_\mu((T_i + T_j)*0.5),$

where $T_{i/j}$ are the temperatures of the two particles in contact and $f_\mu$ the global scalar LUTfriction. Note, while $\mu_0$ depends on the involved particle materials, the temperature dependent part is independent of the type of material.

For a particle-wall contact the same temperature averaging is performed, if a temperature or per-element temperature is defined for the mesh. If no temperature is specified only the particle temperature is taken into account.

Coarse-graining information:

Using coarsegraining in combination with this command might lead to different dynamics or system state and thus to inconsistencies.