Contact Properties

Record of contact parameters

 Description The ContactProperties record stores values for contact parameters. It can be used with any of the Contact Forces components by setting the use record boolean parameter to true and inserting the record name into the contact properties field. The mode parameter selects one of three modes: Linear spring and damper, Linear spring and limited damper, and Hunt and Crossley. The first two use the $c$ and $d$ parameters to set the spring and damping constants. The Hunt and Crossley model uses the parameters ${c}_{n}$, ${d}_{n}$, $n$, $p$, and $q$. See the Multibody Contact Modes help page for the resulting force equations. The $\mathrm{\mu }$ parameter is the coefficient of friction between contacting bodies. The ${k}_{\mathrm{\mu }}$ parameter is a smoothness coefficient for sliding friction, and it scales $\mathrm{\mu }$ by $\mathrm{tanh}\left({k}_{\mathrm{\mu }}\left|{v}_{t}\right|\right)$, where ${v}_{t}$ is the tangential velocity. The $\mathrm{\epsilon }$ parameter specifies a minimum length used when normalizing vectors.

Parameters

 Name Default Units Description Modelica ID mode Linear spring and limited damper Contact force formulation mode $c$ ${10}^{4}$ $\frac{N}{m}$ Spring constant (c > 0 required) c $d$ $0$ $\frac{Ns}{m}$ Damping constant d ${c}_{n}$ ${10}^{4}$ Nonlinear spring constant (c > 0 required) cn ${d}_{n}$ $0$ Nonlinear damping constant dn $n$ $1.5$ Nonlinear elastic force exponent n $p$ $n$ Nonlinear damping force exponent p $q$ $1$ Nonlinear damping force exponent q $\mathrm{\mu }$ $0$ Coefficient of friction mu ${k}_{\mathrm{\mu }}$ $1$ Smoothness coefficient for sliding friction kTANH $\mathrm{\epsilon }$ $0.001$ Minimum vector length for normalization eps