Creating connection for Rear door using ANSA

Objective:

• To apply different PIDs to the components in the FE model and assign suitable connections to the parts in the given rear door FE model.

Given FE Model:

PROCEDURE:

• At first import the given FE model. Now Create different PIDs to the model for your convenient to give connections. Use topo-faces-set PID tool to create PID for different components. Now select the FE for create PID by using feature line option. Click ok the new PID window appears. This procedure will repeat untill the PIDs have been assigned for the entire FE model.

• Now we can start with RBE2 connection in hinge areas. First select elements-RBE2 in nastran deck. Select RBE2-many nodes by using loop option. Now repeat the process for the hinge bolt holes. Many node RBE2 involves connecting many nodes into single spider by depend of single master node. Another option two node RBE2 is assigned by connecting two many node RBE2 spider.

• Now create many node RBE2 for holes of the hinge and connect the many node RBE2(hole area) by using two node RBE2. While creating two node RBE2 care must be taken in assigning DOFs because the door must be rotates in Z axis. So we have to unarrest DOFs in Z axis. So give DOF as 12345. And assign the two node RBE2. This is the one way to assign bolt connection.

• The another way to assign bolt connection which becomes more easy to connect the parts. Here we have 2 more components to connect so we need to create the COG point in the centre component by using Topo-points-on COG.

• Select the COG point and convert COG point as Bold by using convert-3D point-bold. now select the connection manager tool to do further steps for bolt connection.

• Here in connection manager tab, we have assign p1,p2,p3 (if 4th part is there, have to assign p4). to assign p1 by right click p1 tab and press f1 to select the component and click enter to finalise. now assign all p1,p2,p3 now select FE rep type as bolt. assign search distance as 40mm, zones as in/out, DOFs to be 123456. now apply and realize the bolt connection.

• Now give simple rigids by using RBE2-many nodes tool. In this method, we can connect the two holes by one master node called cluster RBE2 node. By selecting loop of nodes in two holes at the same time and middle click to create Cluster RBE2 node Straight away.

• Next we have to create weld connections in particular PIDs. We have deploy both seam and spot weld one by one. we have different methods to create seam and spot weld. Now we shall create seam weld. By creating seam weld first create curve by using mesh-perimeters-feat2curve. after creating curves convert the curves to seam line by using convert-curves-seam line.

• Now select connection manager to to further steps. assign p1 and p2 by selecting p1 as base part where the weld to be deploy. and select FE rep type as overlap shell because here the weld parts are parallel in case the weld parts are perpendicular to each other we have to select Y joint shell as FE rep type. After this assign search distance, base sheet, root shell as double row. Now realize the seam weld is created as follows.

• For Spot welds, We have different method. At first create COG point using on COG tool. assign COG point as 3D point and convert 3D point to Spotweld point by using Convert-3D point-spotweld.

• Now select connection manager and select spotweld point. assign P1 and P2 for selecting PIDs. Assign FE rep type as RBE3-HEXA-RBE3. Assign RBE3 pinflags as 123456. select realize the spotweld deployed at the point.

• Now move to door handle area, Deploy the rigid connection to the holes in door handle by using RBE2-many nodes tool. now we have two master node. now select two master nodes to connect by selecting RBE3-many nodes tool and create master node at the centre.

• Now deploy Con mass tool to the master node by selecting Elements-CONMI-CONM2-nodes in Nastran deck. After selecting the master node, here we have to give mass value (M) in window appeared. the mass value will be tonnes so convert 100g into tonnes as 0.0001. Now select ok to assign the con mass.

• Now we have to connect the window glass using CBUSH connection. For that to begin with create curves using glass edges by using tool as mesh-perimeter-feat2curve.now offset the curve for distance of 5mm by using tranform-copy. After offset, we need to convert the curves one by one into spot line by selecting convert-curves-spot line.

• After that select connection manager to do next step. assign p1, p2 (p3 if it needed) after this select FE rep type as RBE3-CBUSH-RBE3. assign search distance as 30mm, check the keep all branches option.

• assign PBUSH ID by clicking the tab we need press shift+?. the PBUSH ID window appears, assign required stiffness (k) values are as follows.

• After all this, give realize and the result shown below and do similarly to other spot line.
• Here the assigned CBUSH used coordinates as local coordinate system.

• Now we have to reorient the local coordinates to global coordinate system. By selecting Database-elements-CBUSH and select all the CBUSH, Right click and select modify. Ater the selection modify tab appears, assign orient-with cord and CID-0. select ok to all. Now the local coordinate system is changed to global one.

Final images:

Learning outcomes:

• learnt how to convert the points and curves into connecting lines and points using convert and connection manager tool.
• learnt how to assign property and certain values to the connection tools.
• learnt how to create RBE2 elements using nodes in Nastran deck.

Conclusion:

After separate the PIDs from one part. the suitable connections were deployed as per the requirements for the given rear door FE model.