CREATION OF 1 DIMENSIONAL ELEMENTS ON A GIVEN COMPONENT

OBJECTIVES:

To create the following 1D elements on the component as shown in the figure below with given cross-section and DOF: figure: Component

1. 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.

2. 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)= 0.6 mm

   Thickness (t3)= 0.6 mm.

3. Bar element with only x and y DOF with RBE3 link

   Cross-section: H section- Dimension (a)= 5 mm

   Thickness (t1)= 1.2 mm

   Dimension (b)= 10 mm

   Thickness (t2)= 1.2mm.

4. Apply the mass of magnitude 10 with RBE2 link.

5. Apply the mass of magnitude 10 with RBE2 link.

6. Join the two components with spring elements.

PROCEDURE:

1. First for importing model, go to file menu, go to import and click on geometry option. On the tab bar, select the file type as the IGES, now click on the folder icon, browse the IGES file then click open button and click on import button located below tab bar to import model. The imported model is shown in figure(1). figure(1): Imported model
2. To extract midsurface, go to midsurface panel under geometry, go to extraction options, change the offset+plane+sweeps option to offset+planes now click on auto extraction option then select the upper surface of the model and click on extract button as shown in figure(2.1). figure(2.1): Midsurface extraction The extracted surface is shown in figure(2.2). The midsurface can be seen inside the transparent wire framed surface. figure(2.2): Extracted midsurface Mask (hide) the surface of the bracket (surface of parallel bracket body 0 inside components under model tab) by clicking on blue buttion as shown in figure(2.3) to see the midsurface clearly. figure(2.3): midsurface
3. Right click on the middle surface under components in tab bar and select rename option then rename it as bracket 0 as shown in figure(3). figure(3): Renaming midsurface
4. Similarly, extract the another midsurface by selecting the surface and clicking on extract button. The extracted midsurface is shown in figure(4.1). figure(4.1): Extracted midsurface Now, rename the middle surface as bracket, delete PARALLEL_BRACKET_body_0 and PARALLEL_BRACKET_body_1 (by right clicking on them and selecting delete option) and also change the colour of the miidsurface (by clicking on their respective colour box and selecting the colour) as shown in figure(4.2). figure(4.2): Selecting colour for midsurfaces
5. Right click on the browser area and select create then select materials. Give the material name as steel as shown in figure(5). figure(5): Creating material
6. Similarly, create property by create option and name it as bracket. This property is included in the properties option in browser window in the left side of the screen. Now click on the bracket under properties, below browser window on left entity editor page is seen, where assign the material as steel and put the thickness (T) value as 5mm as shown in figure(6). figure(6): Creating property
7. Click on bracket 0 of components and assign the property as bracket. Again, for bracket 1 assign the property as bracket as shown in figure(7). figure(7): Assigning property
8. Now, go to autocleanup panel under geometry. Set the target element size as 5 in both edit parameter and edit criteria (target element size can be taken as default also). Click on surfs button which will display various option for the surface selection, select all and click autocleanup button. The surfaces after autocleanup is shown in figure(8). figure(8): Autocleanup
9. Go to 2D section and select automesh panel. Under automsh panel, click the surfs button and select all option which will select all surfaces as it can be seen on modeling window. Now, set the element size as 5mm and mesh type as quads and click on mesh button. The surfaces after the meshing is shown in figure(9). figure(9): Meshing
10. As the meshing is done, 1D elements can be created on the bracket. First rod having box cross section with RBE2 link is to be created. For RBE2 link (rigids), go to 1D section and select rigids panel. Under create option there are two node buttons upper for independent node and bottom for dependent nodes, click the down arrow button of the independent node and select calculate node, also click on down arrow button on dependend nodes and select multiple nodes as shown in figure(10.1). Now, click on nodes button of dependent nodes and select by path option and select the following nodes shown in figure(10.1). figure(10.1): Nodes selection for creating RBE2 link As we require only translational DOF so only select dof1, dof2 and dof3 only and click create button and thus RBE2 link is created. The RBE2 link is shown in figure(10.2). figure(10.2): RBE2 link Similarly create another RBE2 link on bracket 1 as shown in figure(10.3). figure(10.3): RBE2 link
11. After creating RBE2 link, go to rods panel, and under create subpanel select the element types as CROD and select the nodes on the centre of the link as shown in figure(11.1). figure(11.1): Creating rod Select the centre node of link on bracket 1(blue bracket) which will create rod element as shown in figure(11.2). figure(11.2): Rod element
12. For creating box cross section, go to hyperbeam panel under 1D and select standard section subpanel. By default the cross section is box, so click on create button. After clicking create button the hyperbeam view will be seen, on the bottom left put dimension(a)= 12mm, dimension(b)=10mm and thickness(t)=.75mm as shown in figure(12). figure(12): Box section in hyperbeam
13. Now click on model view (grey coloured folder icon) of model which is above entities on left for the previous view. Then create a new property as rod and on the entity editor( on bottom left) keep the card image value as PROD, material as steel and beamsec as box_section.1 as shown in figure(13.1). figure(13.1): Property of rod This property is created for the rod so go to rods panel under 1D, select update subpanel. Inside updates select elems as CROD from the modelling window, select property as rod and click on update button as shown in figure(13.2). This will update the rod element to rod properties having box cross section. figure(13.2): Updating property of rod
14. For beam, similar to step number 10 RBE3 link is created with all DOF on both brackets as shown in figure(14.1) by selecting RBE3 panel under 1D section. figure(14.1): Creating RBE3 links Go to hyperbeam panel, standard section subpanel and select the standard section type as standard I section and click on create button, which will dispaly hyperbeam view. Put the 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 as shown in figure(14.2).
    figure(14.2): I-section in hyperbeam Click on model view option and creat new property as beam and on entity editor keep the card image as CBEAM, material as steel and beam section as I_section. 2. Go to bar subpanel under 1D section, in bar2 subpanel select property as beam, element types as CBEAM then select node A and node B as central nodes on the RBE3 links and select N1, N2 and N3 as the nodes shown in figure(14.3) and click create button which creates the beam. figure(14.3): Creating beam and its property
15. For bar, first create RBE3 link (as we did in step 14) on both brackets by selecting RBE3 panel as shown in figure(15.1). For only x and y DOF, select dof1,dof2,dof4 and dof5. figure(15.1): RBE3 links for creating bar Then go to hyperbeam panel, standard section subpanel and select the standard section type as standard H section and click on create button, which will dispaly hyperbeam view, put Dimension(a)= 5 mm, dimension(b)= 10 mm, thickness(t1)= 1.2 mm, thickness(t2)= 1.2mm as shown in figure(15.2). figure(15.2): Creating H-section Click on model view option and creat new property as bar and on entity editor keep the card image as CBAR, material as steel and beam section as H_section. 3. Go to bar subpanel under 1D section, in bar2 subpanel select property as bar, element types as CBAR then select node A and node B as central nodes on the RBE3 links and select N1, N2 and N3 as the nodes shown in figure(15.3) and click create button which creates the bar. figure(15.3): Creating bar element
16. For creating mass, first create RBE2 link (similar as step 10) on both brackets using rigids panel under 1D section, by create subpanel (keep calculate node for independent node and multiple nodes for dependent nodes) as shown in figure(16.1) . figure(16.1): RBE2 links for mass Also create RBE2 links on the other side of the both brackets as shown in figure(16.2). figure(16.2): RBE2 links for mass Now create the new property as mass and on the entity editor put the card image as PMASS and scalar mass(M) as 10. Then go to mass panel under 1D section and under create option select all the central nodes of the 4 RBE2 links we created above, put mass value as 10 and property as mass and click create button. The mass elements(CONM2) are created on the RBE2 link as shown in figure(16.3). figure(16.3): Creating mass elements
17. For springs, first create new property as spring and in entity editor put card image as PELAS. Now, go to springs panel under 1D, under create option select dof2, put property as spring and in the modelling window select one node form bracket 0 and another node from bracket 1 and click create button.Similarly create other springs as shown in figure(17). figure(17): Creating spring elements
18. Now, use the tool 1D detailed element representation for the proper view of the cross sections of the elements as shown in figure(18). figure(18): 1D detailed element repesentation
19. Similarly, use the tool 2D detailed element representaion for the proper view of the brackets (component) as shown in figure(19). figure(19): 2D detailed element representation

RESULT AND CONCLUSION:

Different 1D elements such as bar, rod, beam, mass and spring are created on the mentioned areas. Bar, rod and beam are represented with cross-sections as H-section, box and I-section respectively and mass and springs with dots and lines as shown in figure:20. For the easier purpose in terms of prosessing we have created the midsurface of th