24.5. Flexible Roller Group
The flexible roller is a hollow circle as shown in Figure 24.45. The FDR and shell4 elements are used. The primary node of FDR element is located at the rotational center and connected the revolute joint through a dummy body and a bushing force. The secondary nodes of FDR element are the nodes of inner circle. FDR Radius is defined as the inner circle’s radius. Roller Radius is defined the flexible roller’s radius. The shell4 elements are placed between the roller radius and the FDR radius. The shell4 elements are the same FFlex/Shell4 element (3D and Plane stress shell type element). All nodes of shell4 have 6 DOFs. In order to describe the 2D motion, TZ, RX, RY DOFs of all nodes except the FDR primary node are automatically defined by Boundary Condition.
Element: Shell4 + FDR elements
Number of nodes: (No. of nodes at circumference) * (No. of nodes at radial) + 1
Number of shell4 elements: (No. of nodes at circumference - 1) * (No. of nodes at radial - 1)
Shell4 element formulation: RecurDyn/FFlex Shell4 (3D and plane stress type shell element, all node has 6 DOFs.)
Shell4 Material property: Linear elastic/Isotropic
Boundary condition of nodes: TZ, RX, RY (Except FDR primary node)
Contact nodes and contact edges: External nodes and edges.
Figure 24.45 Flexible information of Flexible roller
Figure 24.46 indicates where the flexible information is located in Properties dialog of the flexible roller.
The No. of Nodes at Circumference and No. of Nodes at Radial information must be set only at the creation time. After creating them, their values cannot be changed.
Figure 24.46 Properties dialog for the flexible roller
Figure 24.47 shows the information of material properties for flexible roller. In the material properties dialog, the user can set the material information of Shell4 and FDR elements.
Figure 24.47 Material Properties for the flexible roller
Flexible Roller and Sheet Interactions
There are three contact cases between a sheet and a flexible roller.
Contact case between the linear part of sheet and the node of flexible roller
Figure 24.48 Contact case between the linear part and the node of flexible roller
Contact case between the circular part of sheet and the node of flexible roller
Figure 24.49 Contact case between the circular part of sheet and the node of flexible roller
Contact case between the circular part of sheet and the edge of flexible roller
Figure 24.50 Contact case between the circular part of sheet and the edge of flexible roller
Flexible Roller and Roller Interactions
There are two contact cases between the rigid roller and the flexible roller.
Contact case between the circle of roller and the node of flexible roller
Figure 24.51 Contact case between the circle of roller and the node of flexible roller
Contact case between the circle of roller and the edge of flexible roller
Figure 24.52 Contact case between the circle of roller and the edge of flexible roller
Flexible Roller and Flexible Roller Interactions
There is a contact case between a flexible roller pair.
Contact case between the edge of flexible roller and the node of flexible roller
In this contact case, the base body has edges. And the action body has nodes. Therefore, the contact search algorithm is one, the actual search performs two times. In the 1st search, the flexible fixed roller is defined as a base body (Edge), the flexible movable roller is defined as an action body (Node). And then, in the 2nd search the base and action condition are switched.
The contact normal direction is always perpendicular with the edge surface.
Figure 24.53 Contact case between the edge of flexible roller and the node of flexible roller