9.9. Contacts in FFlex

Dynamic analysis of many mechanical systems is often involved with contacts among bodies or flexible bodies. To solve a contact problem of the flexible body, the nodal synthesis method is used to represent its local behavior in RecurDyn/FFlex. An external surface of the flexible body can get from a finite element model and the contact surface is approximated by either triangular or rectangular patches. The contact force can be calculated with a compliance contact model, and which one of the most known mathematical approximation of the dynamic behavior of a contact pair has been that a body penetrates the other body with a relative velocity at a contact point in a field of multi-body dynamics.

The Contact Forces in RecurDyn/FFlex are mainly divided into two classes.

  • They are contacts with a flexible surface and a flexible curve.

  • The cross section of the flexible curve is assumed to be a circle.

  • The flexible surface is approximated as a triangular or rectangular patch.

  • The FFlex body is contacted with a rigid body or other FFlex body by using the following Contact Forces.

  • Even though the contacted patch sets are within the same body, they are contacted.