Torus Rectangle Contact - MapleSim Help

Torus Rectangle Contact

Torus-rectangle contact force model

Description

The Torus Rectangle Contact model connects Torus and Rectangle contact elements.

 Activation Contact forces are generated only when the contacts are enabled. The active parameter selects how the contacts are enabled. It has the following settings: Always Active, the default, means the contacts are always enabled. Boolean Signal means the contacts are enabled when the enable contact boolean input is true. Start/Stop Time means the contacts are enabled at specified start time, ${T}_{\mathrm{on}}$, and disabled at a specified stop time, ${T}_{\mathrm{off}}$. The on/off parameter is used with the Start/Stop Time selection and has the following settings: Start Time means the contacts are enabled at ${T}_{\mathrm{on}}$. Stop Time means the contacts are disabled at ${T}_{\mathrm{off}}$. Start/Stop Time means the contacts are enabled at ${T}_{\mathrm{on}}$ and disabled at ${T}_{\mathrm{off}}$.
 Contact Properties The use record boolean parameter, if enabled, specifies the name of an external record parameter that defines the parameters of the contact. 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, 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.

Connections

 Name Description Modelica ID enable contact Optional boolean input; enable contact enable_contact ${\mathrm{port}}_{1}$ Connection to tori port_1 ${\mathrm{port}}_{2}$ Connection to rectangles port_2

Parameters

 Name Default Units Description Modelica ID active Always Active - Selects contact activation active on/off Start Time - Selects start/stop times onoff ${T}_{\mathrm{on}}$ $0$ $s$ On time Ton ${T}_{\mathrm{off}}$ $0$ $s$ Off time Toff use record $\mathrm{false}$ - Use contact properties record useRecord mode Linear spring and damper - Contact force formulation mode $c$ ${10}^{4}$ $\frac{N}{m}$ Spring constant (c>0) c $d$ $0$ $N\frac{s}{m}$ Damping constant d ${c}_{n}$ ${10}^{4}$ - Nonlinear spring constant (cn>0) 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 $\mathrm{\epsilon }$ $1.{10}^{-6}$ - Minimum length of vectors for normalization eps contact properties - Name of contact property record component conparams ${n}_{\mathrm{torus}}$ $1$ - Number of tori nTorus use torus to torus contact $\mathrm{false}$ - True (checked) means model contacts between tori useTorusTorusContact ${n}_{\mathrm{rectangle}}$ $1$ - Number of rectangles nRectangle ${k}_{\mathrm{edge}}$ $1000000000$ - Smoothness coefficient for contact behavior near edges Kedge ${k}_{\mathrm{tol}}$ $0.001$ - Tolerance for detecting the special case when the torus is parallel to the plane Ktol ${k}_{\mathrm{conv}}$ $1.{10}^{-9}$ - Error control used in iterative contact point calculations Kconv ${n}_{\mathrm{iter}}$ $1000$ - Maximum number of iterations Niter