Rigid connections for the Car Rear Door

Aim: To do a connections for the given Rear Door FE Model and and to use the different types of coonection techniques such as Seam Welding ,Spot Welding,Nut and Bolt connection etc

Procedure:

1)Import the Door FE model into the ANSA Work Bench.

2)Study the model in terms of geometry and mechanism

3)Connection of Latch and hinge Portion

4)Connection of Bolts and Nuts

5)Connection of Weldings

6)Connection of Window Glass

7)Connection of Door Handle

1)Import the Door FE model into the ANSA Work Bench.

• Open the Door Fe Model into the ANSA Work Bench

2)Study the model in terms of geometry and mechanism.

Once you open the model understand the geometry and mechanism of the model and the areas where the model has to be rigidised or to be connected with suitable techniques.

2)Connection of Latch and hinge Portion

Let us start the connection of the door for the hinge and latch areas.

• Connect the overlapping Hinge areas through RBE2 Cluster Element by selecting the Perimeter Nodes(Nastran deck>Elements>RBE2>Many Nodes).

• Once the Cluster RBE2 Element is created,the rotating link is to be connect using two Node RBE2 Element(Nastran deck>Elements>RBE2>Two Nodes).In the Property Tab we need to Give DOF as 12345 as the hinge is arrested in all direction except the Rotational Z axis in order to open and close the door.

Same procedure has to be followed for Lower Hinge.

4)Connection of Bolts and Nuts

Let us Connect all the Nuts and Bolts Conection.Bolt Representaion can be made manually as explained above like Cluster RBE2 or 2 Node RBE2.Here we will study how to connect the Bolts and Nuts representation in Auto mode.

• First Identify the Bolt and Nut Area.

• In Topo Mode>Points>On COG create a 3D points on any of the Bolt Holes.

• Convert the 3D points into the Bolts(Assembly Manager>Convert>3D Points>Bolts) and select the 3d points.3D point sConverted to Bolts will be represent in ANSA as shown in figure below.

• Once the point is converted to Bolt,Open the Connection Manager and select the Bolt by box selection.

• Select FE rep Type as Bolt and Assign P1,P2 and P3 Surfaces of the bolts wich we need to connect.To Select P1,Right Click on P1>Modify>Click F1 and select the Component and press Confirm.Foloow the Same procedure for P2 P3 and So on.
• Assign Search Dist as 20 and Body type as RBE2.

• Once done with filling required datas,Click Apply and Realize the Connection.Thus the Bolts Connection have been made shown in figure below.

Folow the ame procedures for all the Bolts representation.

5)Connection of Weldings

Inside the Panel we found that there is a mechanism for Power window for sliding of glass up and down.So we need to ake the Spot Weld Connection as well as RBE2 Connection to complete the transmission.As we studied the RBE @ element creation in the above ,Now let us how to connect two parts by Spot Welding Method.

• To do a Spot welding we Need to create a 3D Points as explained above.
• After creating the Points,Convert that points to the Spot Welding Points as Shown in the Figure below.

• Now Open the Connection Manager and Select the Spot Welding Points.

• Select P1 and P2 for which the spot weldings have to be done.
• In the FE Rep Type Select RB3-HEXA-RB3 for the spot weldings.
• Fill the required data such as Search Distance as 50 and assign new property for Spot welding Shell (PSOLID ID).To create a PID We need to Click "Shift+?"
• Once you have done with filling required data Click on Apply and realie the Welding.Once realizing the connection the Spot welding has been made on the Component as shown in figure below.

Thus Same procedure have to be followed for the Spot Welding wherever required.

6)Connection of Window Glass

Let us See How to make Connection for the Rubber Strip and the Window glass.

• Create the Feat2Curve (Mesh Mode>Perimeter>Feat2Curve) all around the Window Glass as shown in the Figure below.

• Now Convert the Curve to the Seam Lines(Assembly Manager>Convert>Curve>Seam Line).

• Now Go to the Connection Manager and Select the Spot Lines for wich the connecton have to e made.
• Fill all the required data such as FE Rep Type:RB3-CBUSH-RB3,Search Dst:50 and Assign New PID.
• Select the P1 and P2 for which the C Bush Connection required and also mention the Distance between the two CBUSH which is represented as "S" in Connection Manager.
• In the Connection Interface Enable Keep All Branches

• Once the all the data filled ,Click on Apply and Realize the Connection.C BUSH Connection have been made as per requirement as shown in figure below.

Thus the CBUSH Connection have been made at One Side.For the opposite side we need to transform the botto curve at distance of 10 and foloow the same procedure.

7)Connection of Door Handle

In the Given FE Model it is found that there is a provisio for Door Handle which is not shown in the model.But for NVH Analysis we need to represent by Conecting the two Ends where the handle will be fixed and at the center we need to appky the approximate Mass which is cinsidered as the Mass of the Door Handle.

• First Rigidise the two Ends of the handle using Many Nodes RBE2(Elements>RBE2>Many Nodes).

• Now Connect those Rigidised RBE2 Elements with Two Nodes RBE2 Element as shown in the figure below.

• Once the Handle is Rigidised we need to Apply Approximate Mass of the Door Handle at the Center of the 2 Node RBE2.
• For that Go to Nastran Deck>Elements>CONMi>CONM2 and select the Node for which the Mass to be added as shown in the figure.

• In the Mass Tab Enter the Mass Value of the Handle(M) and Click OK.
• Thus the Mass has been added to the Door Handle.

Learning Outcomes:

1)Understanding the Mechanism of the Car Door.

2)Different types of Connection Techniques.

3)understand How to Apply Mass to the rigid Body.

4)Representation of Spot Welding and Bolt and Nut Connection.

5)Degrees of Freedom and its importance in NVH Analysis

Conclusion:

Thus the Connection for the Car Rear Door Model is done and can be Concluded that for any Analysis ,understanding of Mechanism is very Much important before starting the Connection.All the Connection procedure is same for all the models but the requirement might differ from models to models depending upon the analysis.All the possible Connections are done for this models and the model is ready to give for the next Process.

Google Drive Link For the Model:

https://drive.google.com/file/d/1RJkjayfZ75t5-alELqdkMUA_AaTvPMHL/view?usp=sharing