Prescribing boundary conditions and applied loads

As shown in Figure 1, the left end of the plate is completely fixed; the right end is constrained to move on rails that are parallel to the axis of the plate. Since the latter boundary condition direction does not coincide with the global axes, you must define a local coordinate system that has an axis aligned with the plate. You can use the datum coordinate system that you created earlier to define the local material directions.

  1. In the Model Tree, double-click the BCs container and define a Displacement/Rotation mechanical boundary condition named Rail boundary condition in the Apply Pressure step.

    In this example you will assign boundary conditions to sets rather than to regions selected directly in the viewport. Thus, when prompted for the regions to which the boundary condition will be applied, click Sets in the prompt area of the viewport.

  2. From the Region Selection dialog box that appears, select set EndB. Toggle on Highlight selections in viewport to make sure the correct set is selected. The right edge of the plate should be highlighted. Click Continue.

  3. In the Edit Boundary Condition dialog box, click to specify the local coordinate system in which the boundary condition will be applied. In the viewport, select the datum coordinate system that was created earlier to define the local directions. The local 1-direction is aligned with the plate axis.

  4. In the Edit Boundary Condition dialog box, fix all degrees of freedom except for U1.

    The right edge of the plate is now constrained to move only in the direction of the plate axis. Once the plate has been meshed and nodes have been generated in the model, all printed nodal output quantities associated with this region (displacements, velocities, reaction forces, etc.) will be defined in this local coordinate system.

Complete the boundary condition definition by fixing all degrees of freedom at the left edge of the plate (set EndA). Name this boundary condition Fix left end. Use the default global directions for this boundary condition.

Finally, define a uniform pressure load across the top of the shell named Pressure. Select both regions of the part using ShiftClick and then click Done. When prompted to choose a side for the shell or internal faces, select Brown, which corresponds to the top side of the plate. You may need to rotate the view to more clearly distinguish the top side of the plate. Specify a load magnitude of 2.E4 Pa.