Technical Support

RecurDyn V9R1 : Multi-Body Dynamics 글 편집

Geometry Modeling

Various improvements have been made to Rigid body geometry modeling.

  • Helix Curve: The Helix Curve tool creates a helical curve. A Helix Curve can be used in the Mesher to make a Sweep Mesh.
  • Fill Curve: Fill Curve creates a Surface from the interior of a closed curve. This surface can be used to generate a Shell Mesh in the Mesher. The Shell Mesh can then be used in a Sweep Mesh, Extrude Mesh, or Spin Mesh in the Mesher.
  • MultiEdge/MultiFace: In General Body or Body Edit Mode, it is possible to create curves or surfaces from multiple geometry entities contained in a single RecurDyn body. For this purpose, the MultiEdge and MultiFace creation methods have been added to the Edge creation tool and the Face Surface creation tool.
  • Sew: Sew connects surface geometry. It will fill small gaps in a surface if gaps exist. It removes redundant edges in the geometry. It can create a new, connected surface from 2 separate surface geometry entities if the surfaces are very close to each other or have touching edges.
  • Offset Surface: Creates a surface that is offset in the normal direction to the surface by a user-specified amount.
  • Fill Surface: Creates a solid by filling the interior of a closed surface that encloses a volume.
  • Thicken: Creates a solid by adding a thickness to a surface.

OnOff Joint

RecurDyn now has a joint called the OnOff Joint. This joint is a kind of Fixed constraint with the ability to constrain between 0 and 6 degrees of freedom. The OnOff Joint has the ability to enable and disable the constrained degrees of freedom during the simulation. An Expression is used to enable or disable the constraint during the simulation.

  • Constraint (Reference From Action Marker): Selects degrees of freedom to be constrained
  • Include Condition: Registers ON/OFF condition with Expression

The OnOff Joint can be used to increase the speed of computation when it can be used instead of a contact element. For example, it can be used with a device that firmly grabs things, like a robot arm that grabs an object. In this case, an OnOff joint can be used instead of contact elements between the gripper and the object. Another example is a projectile fired from a tube. The OnOff constraint can be used instead of contact elements between the projectile and the tube to significantly increase the speed of computation.


Contact related options, convenience features and new 2D Contact have been added to enable more accurate analysis for results.

  • Open Face in Cone-In-Cone Contact: The previously existing Cone-In-Cone Contact element now supports an Open Face for Base Cone so that there is no contact between the inner cone and the base of the outer cone. It is much easier now to define cone contact for cones that have open ends, which will make Cone-In-Cone contact more useful.


  • Contact Point Sorting: Approximate contact location and contact concentration area can be verified through animation when checking the result of Geo Contact. It is much easier to understand the contact behavior now that the points of largest contact force are automatically chosen. If Generate the Contact Output File (*.con) is selected in the Geo Contact Properties dialog box, then the Contact Point data that is written to the *.con file will be sorted from largest magnitude to smallest.
  • Geo 2D Circle Contact: This is a 2D contact element for contact between a circle and a curve. The Geo Circle Contact element’s contact algorithm is similar to the existing Geo Curve Contact algorithm, with optimizations for the circular shape of one of the curves. Furthermore, if the circular body is chosen to be a spherical geometric entity, RecurDyn automatically extracts the 2D shape for the circle from the radius of the sphere.