3.4.3: Line-Joint

The "Line-Joint"-component lets one specify linear hinges inside or at the boundary of shell-patches.

Fig. shows an example which involves two shell patches "A" and "B" made up of two shell elements each. Patch "A" is fully fixed on one side and connects to "B" via a linear joint symbolized by a purple line. Shell "B" can rotate about the joint's X-axis given by the read arrow on the purple line.

The "Line-Joint"-component provides these inputs to specify the non-rigid connections between shells:

  • "J-Curve": A line-like curve which connects the nodes of shell which are part of the line-joint. The direction of the curve specifies the joint's X-direction.

  • "AtElemId": Identifier of the shell patch on which the joints shall be specified. The default is an empty string which signifies that the joijnt is potentially attached to all shells in the model.

  • "Y-Ori": sets the joint's local Y-axis. It points towards the shell patch on which the joint shall be attached. When "Joints" is enabled in the "ModelView"-component the Y-axis appears as a green arrow on the hinge line.

  • "Z-Ori": In case the joint's Y-direction is (0,0,0) or parallel to the joint-line direction, the joint's tripod gets created via the joint-line's X-direction and the Z-orientation. The joint gets attached to those elements which the joints Y-axis points to. The Z-axis is symbolized by a blue arrow when displayed via the ModelView-component.

  • "DAlpha": Maximum angle [deg] between a mesh-face and the Y-Ori for adding a line-joint to it.

  • "Ct": Vector of translational spring stiffness of the line-joint.Values take effect only, if the corresponding DOF is set to hinged in the "Dofs"-input of via the radio buttons in the submenu "Joint definition".

  • "Cr": Vector of rotational spring stiffness. Is analogous to "Ct".

  • "Dofs": List of degree of freedom indexes (0:Tx, 1:Ty, 2:Tz, 3:Rx, 4:Ry, 5:Rz) to be released in addition to those selected via the check-boxes in the sub-menu "Joint definition". Add a 'ValueList'-component for easy selection or use 'Expand ValueLists' from the component's context menu.

The radio-buttons under "Joint definition" signify released joint DOFs when enabled. In order to see the joint's local coordinate system enable "Joints" in the "Display Scales"-submenu of the "ModelView"-component. The "Local axes"-slider in the same submenu can be used to scale the arrows.

Last updated