Mid-Surfacing and 1D Elements in HyperWorks

OBJECTIVE:

Create 1D elements on the component with given cross-section and DOF. Assign the elements at each of the points as shown in the figure.

a. Rod element: with only translational DOF and RBE2 link

Cross-Section: BOX

Dimension a = 12 mm, Dimension b =10 mm, Thickness t = 0.75 mm

b. Beam element: with all DOF and RBE3 link

Cross-Section: I Section

Dimension a = 8 mm, Dimension b = 10 mm, Dimension c = 8.5 mm, Thickness t1 = 0.75 mm, Thickness t2 = .6 mm, Thickness t3 = .6 mm

c. Bar element: with only x and y DOFs with RBE3 link

Cross-section: CROSS section

Dimension DIM1 = 5 mm, Thickness DIM2 = 1.2 mm, Dimension DIM3 = 10 mm, Thickness DIM4 = 1.2mm

d & e. Apply the mass of magnitude 10 with RBE2 link

f. Join the two components with spring elements

SOLUTION:

The aim is to create 1D elements in the given model. The model consists of two brackets with circular holes. The element type, cross section geometry, dimensions and positions are defined in the problem statement.

1. The given 3D model of the bracket is imported into the workspace.

2. Before creating the elements, we generate the mid surface of the components. The midsurface option can be found in the geometry tab. In this option, select skin offset option in the extraction options. Select the surface option in auto extraction, define the surfaces from which the mid surface is to be generated and press extract button.

3. Create a new component in the model tree and create the mid surface for the second component. Assign this newly created mid surface to the component using move in organize option in tool tab. After step 2 & 3, we have generated the md surface.

4. In the next step, create washer splits around the circular hole features in the components. This can be done in quick edit in the Geom tab. The width was set as 5mm.

5. Create a 2D mesh in the components with element size as 5mm. This can be carried out in automesh option in 2D tab. The element type was set as mixed. To create a finer mesh along the curved regions, increase the number of nodes by clicking the left button on the node value.

6. Steel material was created and was assigned to both the components.
7. Properties for both bracket components were created and assigned.
8. The cross sections as defined in the problem statement were created using the hyperbeam tool. Three sections were created, namely box, I and Cross sections were created with dimensions as given in the problem.

9. Under the properties section in the model tree, properties were defined for the rod, beam and bar elements and the corresponding cross sections were defined.
10. To create the links, the nodes along the circular feature were selected and the RBE2 and RBE3 links were created.

11. The rod, beam and bar elements were created by selecting the centre nodes in the appropriate links. The DOF's were defined as specified in the problem statement. To create the elements, go to 1D tab, select element type and define the nodes.

12. For each of the element created, the appropriate cross sections as defined in the problem statement were assigned from the properties section.

13. To create the mass elements, the RBE2 links were created at the required points. To assign the mass, go to 1D tab, select masses, select the node, define the mass value and create the element.

14. Finally, to create the spring elements, go to 1D tab, select spring element, define the nodes between which the element has to be created and press create button.

The final model after creating all the elements as defined in the problem statement is as follows:

CONCLUSION:

1. The mid surfaces were created for the given components and the 2D mesh was generated.
2. Bar, Rod, Beam, Mass and Spring elements were created in the model.
3. RBE2 and RBE3 links were created at the specified holes.
4. Different cross sections were created using the Hyperbeam tool and was assigned for the appropriate elements.