# Generic Bushing Model

The following describes a generic representation of a bushing model.

Let:
• t be the independent variable time
• p be a set of model coefficients or parameters used in the bushing definition
• x(t) be a set of internal states used in the bushing model
• u(t) be a set of known inputs provided to the bushing
• y(t) be the forces generated by the bushing (the outputs)
Then the general form of the equations representing a bushing is:(1)
$\begin{array}{l}F\left(\stackrel{˙}{x},x,u,p,t\right)=0\\ y\left(t\right)-G\left(x,u,p,t\right)=0\end{array}$
The functions F(…) and G(…) depend on the bushing model that is used. The above equations can be combined into one single expression having the form:(2)
$H\left(\stackrel{˙}{x},x,u,p,y,t\right)=0$