Challenge

Assigning different connection types for a Rear Door of Automobile using ANSA

Objective:

For the given Rear Door FE model, applying the techniques and the elements to implement the connections.

Introduction:

Door assembly is one of the important assemblies in the Automobile and there are many connections as it is the system with many subsystems or attachments namely: Door Latch, Hinge, Glass, Rails, and suitable connections are required as it plays a vital role while running NVH parameters.
Connections are of many types and are classified with respect to each part.

Some of them which are used widely in ANSA are:

Bolt, Seam Weld – Over Lap shell & Y – Joint Shell, Adessive, Spot Weld, etc
For seam weld connections users can define the connections according to the orientation of weld by CAD engineer.
In ANSA we generally use Over Lap Shell Joint for parallel weld connections and Y – Joint shell for Perpendicular weld connections by choosing the right parts P1 & P2 and defining it in the connection manager.
Here in this model, we are more concerned with Bolt, Rigid, C Bush connections mainly and are explained along with proper screenshots.

Importing CAD in ANSA & Assigning Property Id:

Bolt Connections:

In order to create so, initially, I created a COG point.
Converting that point into Bolt connection and created a rigid connection across 2 surfaces suing RBE2 connections.

Hinge Region Explanation:

After creating the rigid connection at the Hinge parts need to be joined with 2 node RBE2 connection created under Nastran Deck.
In order to define the bolt connection for the Hinge region, the degree of freedom should not be restricted to all degrees of freedom

Because the door is pivoted at the Hinge and should move along the particular fixed direction, so we need to remove the rotational axis in which the door should not move.
Here the rotational Z-axis (6) is restricted with respect to the global axis for the Hinge region so that the door restricts only 2 coordinate Axis.

Cluster RBE 2 definition:

In order to join some of the rigid parts that tend to join we generally use cluster many RBE 2 for connection to define it.
This forms a rigid connection over 2 parts.

Individual Connections:

Individual holes are given zone cut under Mesh Deck then making it rigid connecting with many node RBE2 in order to gain the extra strength at the particular region/hole.

Spot-Weld Connections:

Some parts where the bolt or rigid connections are not possible those need to be welded and defined.
In order to do so, I created a Weld Spot and by using convert tool changed it to spot weld point.

Now by selecting the spot weld point and defining it into connection manager, was able to create a spot weld region across 2 components with the help of RBE3-HEXA-RBE3 connections.

Handle Region

Usually, the regions across the Handle holes are considered as Mass elements and need to be defined as Rigid with the help of many node RBE2 connections and to be joined again with the help of many node RBE2 connections which defines the Mass.

The center point created needs to be defined with a particular mass according to the mass of the Door Handle (I considered as 100 gms).
We should define the Mass under Nastran Deck<Elements<CONMi<CONM2<Nodes.

Select the COG node and define the Mass (M) by converting 100gms in Tones (US Standards).

Windows Glass Region

The basic concept here while giving connection for a structure like glass material indoors we need to remember that the glass is a brittle material and we can’t join by weld or bolts or adessive type of connections. Yes, we can use adessive for front windshield and rear Wiper windshield.
In order to define the Glass kind of regions for the door, the basic thumb rule is that it should a closed component whenever we want to perform connections and is attached to the glass rail mechanism.
The weatherstrips/damping elements are present on either side at the bottom where the glass is pushed or pulled and outer side on remaining surfaces which also acts as guides.
These are considered an important structure for HVAC functioning inside the cabin.
In order to determine the glass part initially, we need to create a curve for all the glass path.

By using Mesh Deck<Perimeters<Feat2curve
These curves generated need to be converted to spot line as we have mechanisms for this glass, if there is no mechanism, we can use adhesive for parts like a front windshield.

The bottom Spot line is projected the other line using Transform
The Bush ID is created and the 6 stiffness values K1-K6 are given.
Define the spot line as RBE3-CBUSH-RBE3 elements as it the best to define the Bush elements and each bush elements have the stiffness along the 3 axes (X, Y, Z).
Once we realize the elements, a number of CBUSH elements are formed across the Spot line and make sure to select all elements under Quality Tab<Representation.

All the CBUSH elements formed need to be aligned with the global coordinate axis by making one axis as 0 so that it will be aligned with the global axis of the vehicle.
Latch & Check Arm are not needed for connection as they are attached to other parts.

Result:

Hereby all the connections are successfully deployed for the Rear Door Assembly.

Learning Outcome:

Was able to understand different types of connections and deploying it with a particular part/region
Spot-weld, CBUSH, Bolt, Seam Weld, Rigid, Cluster are some of those connections.
Importance of Zone cut for individual connections.
Door Handle connection determining the Mass of it.
Latch & Hinge regions.
Fixed and movable glass windows

Google Drive Link: https://drive.google.com/file/d/1mO_7zCpsyoe72mksCi0aPJbf9bu4DOAW/view?usp=sharing

Ship work like this
in your own course.