Week 6 - Creating connection for Rear door

Aim: Forgiven Rear door FE model, Create and Apply different PIDs for different components. Perform suitable connections.

• Given CAD model of Rear door FE model.

• Create and Apply different PIDs for different components

• At the hinges, the bolted joint is used in the real scenario. So to replicate that virtually, the bolted joint is created. For creating a bolt connection, A COG point is required. Which is available in "Points" from "Topo" module.
• After selecting the COG option, any one of the closed perimeter should be selected.

• Then the created COG point should be converted to a 3D point from the "Convert" option in assembly manage.

• Then by middle-clicking, a dialog box appears as shown in fig 4.12. Which represents the connection manager. In which some parameters such as PID 1, PID 2, FE representation type should be selected. Then by selecting Apply, Realize the connection will be realized.

After realizing the connection, the formed bolt connection with the bolt stem appeared.

• Then the connection is deployed using the RBE2 cluster in some regions as shown in fig In which the RBE2 element---> Many nodes option should be selected. RBE2 cluster means, connecting so many nodes.

• Then the connection is deployed at the door handle region.
• Initially, the RBE2 elements with many nodes options are used to connect all nodes at the perimeter of the handle. As shown in fig Inorder possesses a rigid nature.
• Then an RBE2 element with many nodes is used to connect both master nodes. After connecting, it appears.

• Then to represent the weight of the door handle, as in the case of a real-world scenario. The mass can be assigned by using the "CONMi" ---> CONM2---> Nodes. In the NASTRAN deck module.
• A weight is assumed as 1 kg and entered as "1e-4"(Which will be in the form of tonnes). As shown in fig And this is applied to the master node at the center.

• In this step, the rail which is responsible for the movement of side glass to up & down and the side glass are only isolated to have clarity on them.
• By isolating those components the thing noticed is, the rail component should be enlarged a bit more till the glass. This can be done by using the "Move free" option in grids from the mesh module. As shown in fig And the nodes at the edges are selected to
  enlarge in the z-direction.

• After enlargement, it appears

After performing reconstruction, the rail component appears as shown in fig.

• These two components are connected by using RBE2 elements. To possess rigid nature. So for proper selection of entities, the elements option is enabled and Which indicates the entities selected will be elements.
• After selecting the elements and confirming the connection, the connection is deployed by an RBE2 cluster element between rail & glass

• In some regions where the parts overlapped with each other with the minimal space between them is joined using the spot weld option. In order to represent the joint. So for creating a spot weld connection, the COG point is required. And the edges of the element are selected by choosing the "on COG" option as shown in fig.

• After creating a COG point, it is converted to a spot weld point. This is done by choosing, "Convert" option from the assembly manager. And in that, the connection type is specified as "spot weld point"

• Then to realize this connection, the connection manager is opened from the assembly manager. And the converted spot weld point is selected. And some parameters are specified as shown in fig And the FE representation of a spot weld connection in the NASTRAN deck is "RBE3-HEXA-RBE3"

• After realizing the connection, it appears as shown in fig. Similarly, the spot weld connection is deployed. Wherever it is necessary.

• As the side glass is surrounded by a component called a "Weatherstrip" which is made up of rubber material. And widely known as "Beading". So to represent that, the CBUSH elements are used. Because it possesses elasticity in all three directions.
  So, initially, the curves are needed. For that, the "FEA to curve" option in the perimeters from the topo module is used. Which is
  shown in fig

• And the FEA edges are selected one by one and then it is converted into curves, which are represented by purple-colored lines at the edges.
• As the weatherstrips will be at both sides of the glass at the bottom, the CBUSH elements should be deployed at both sides of the bottom. For doing that, the curve created at the bottom should be copied by using "Transform" and moved to a certain distance such as 1mm.
• Then these curves are converted in to "spot line". And then this spot line is realized by selecting the line by line and specifying
  the parameters such as spacing between the CBUSH elements as 10 mm, specifying PART1 & PART 2, specifying FE representation type as "RBE3-CBUSH-RBE3" and assigning RBE3 pin flags(DOF) in all directions.

• Then the PID should be created, which is done by selecting "Shift+?" from the key-board by placing the cursor in the PBUSH ID row of fig After selecting a "new" option, a dialog box appears as shown in fig. WHich represents PID for the CBUSH elements. In that, the 6 stiffness values are entered, which are predefined

• After creating the new PID for CBUSH elements, the CBUSH elements will be formed in between the side glass and outer part.

Similarly, the CBUSH elements are created on all sides of the glass. Then the created CBUSH elements are isolated. After isolating them the thing noticed is, the CBUSH elements are in different orientations. As shown in fig. Which may lead to inappropriate results at the time of the simulation.

So to overcome that problem, the orientation of all CBUSH elements should be changed to that of a global co-ordinate system, For doing that, all of the CBUSH elements are enabled from the database window.

Finally after deploying all necessary connections to the given rear door mode.

Conclusion:
Finally, Deployed the necessary connections for the given meshed rear door model.

By performing this challenge, the following aspect can be learned:
Deploying connections using rigid (RBE2) elements in ANSA.
Deploying connections using Bolt joints in ANSA.
Deploying connections using CBUSH elements in ANSA.
Applying the mass to a node(At the door handle).
Assigning the Degrees of freedom for the created elements.
Changing the orientations of CBUSH elements.