Bond graph modeling of dynamics of soft contact interaction of a non-circular rigid body rolling on a soft material

• Contact between a non-circular rigid body and a soft material is modeled.
• An algorithm detects contact nodes on the soft material at each time step.
• The model determines contact area and force distribution over it.
• To model the contact, only soft material is discretized, not the rigid body.
• The model is applicable to all geometries of the rigid body.

The bond graph model for soft contact interaction between a circular rigid body and a soft material has already been developed and validated experimentally in a previous work. The present work further extends the approach to soft contact interaction for non-circular rigid bodies rolling on soft material which is difficult to model otherwise. An elliptical disc is taken as the non-circular rigid body as an example. An algorithm is developed to detect nodes of the soft material which contact the disc at any time. The contact interface between the two surfaces is assumed to be viscoelastic which is the penalty approach with additional dissipation. The model is applicable for all geometries of the rigid body. The contact model also takes normal force and tangential frictional force into account. The model dynamically determines the number of contact nodes, and hence the contact area at any time as the contact interface changes. Results of simulation of the model, based on code generated algorithmically from the bond graph structure, provide better understanding of the soft contact interaction issues involved.