Rear Door Connections

1. Aim: Understanding the basic types of connections, where to use these connections to make constrains and how to connect the parts by using different connections and their uses.
2. Objective :

• Understanding different types of connections.
• Different methods to implement these connections.
• How to form a weld and bolt connections.

3. Body of content:

• A car door is a type of door, typically hinged, in front of an opening which is used for entering and exiting a vehicle. A vehicle door can be opened to provide access to the opening, or closed to secure it. Here in this particular model the connection of an automobile car with the car body and the basic connections which are needed to be done before doing performing any further process are shown.
• As a typical car door, this particular sub-system is itself is a system, however, for the study purpose this model is taken and the necessary parameters taken as given by the instructor.
• Different connections are being done and those along with necessary information are shown below.

3.1.1 For generating the bolt, COG is created and using convert command it is converted into a bolt.	3.1.2 After converting the point into a bolt, the connection is generated using the connection command & connection manager get opened.
3.1.3 FE type is selected as Bolt and proper surfaces are selected and the connection is realized. Here the connection is shown with a bolt stem.	3.1.4 Same connection at a different point is shown without a bolt stem.

• The above method is used to generate a bolt connection and how to generate the bolt with and without the stem.
• Rigid models are initially done on all the bolted areas. We try to make the connection at hinge areas initially by creating 3Dpoint and converting them into bolts.
• The following images show, how the connection for the bolted areas which are to be hinged with the automobile body is done.

3.1.5 Area where bolt connection is needed to be formed.	3.1.6 Spider connection has been made in order to represent a bolt connection and this hinge requires a DOF in the direction in which the door will open.
3.1.7 Image shows a connection made at hinge section where a stem is formed which is constrained in 5 direction and not in 6th to allow motion of the door in that direction.	Here is a 2 node RBE2 is used to constrain all DOF of all axis but in order to allow the door to open wrt to z-axis 6th DOF is removed in order to allow the door to move in that particular direction. Similarly has to be done with bottom hinge connection. Removing the DOF in the wrong direction will result in rotation of that particular component in that axis while simulating.

• At some areas, a spot weld is needed to be created. Here this particular part, shown below, is connected to the body using RBE3 Hexa weld. This is a solid weld. The slight difference between RBE2 & RBE3 is that, in RBE2 centre node is a master node and outer nodes are slave nodes, where are in the case of RBE3 the centre node is slave node and outer nodes are master node.

3.1.8 Formation of a spot weld.	3.1.9 Property has to be assigned for the Spot weld
3.1.10 Property table for spot weld.	3.1.11 Forming a connection using RBE3 Hexa, which result in the formation of a spot weld as shown in the image.

In order to avoid any unnecessary movement of other components while performing a simulation of the FE, it is necessary to constrain these components which the base body avoid any further errors. These are shown below.

3.1.12 Some other areas where connections are to be done.	3.1.13 Area where spider connection has to be used.
3.1.14 Spider connection has done which connects the part with the door body.	3.1.14 Connection at some other point for supporting parts.

Door handle:

The door handle is generally generated as a mass element and complete FE modelling of the door handle will not be done. We need to capture rigid like shown in the image and we will be creating a two-element rigid and assign mass at the master node. We need to assign the mass in tonnes and not in gram or kg.

3.1.15 Way of generating a mass at the master node.

3.1.16 Mass has been given in tonnes. We can see a mass element getting generated at the centre.

Window connection:

For the window, curves are getting created in order to convert them into spot lines which are used to represent these elements. Ans it is considered as a weld line and not an adhesive line. After converting these lines, these lines need to realize. To realize, we need to do it as a CBUSH RBE3. C BUSH is a spring element which has a damping coefficient of stiffness values. Earlier we used to use C elastic elements.

Initially, curves are getting generated around the window and these curves are needed to be converted into spot lines. The procedure to generate these connections are given below.

3.1.17 Converting these curves into spot lines, using convert command.	3.1.18 Proper has to be to assign to the bush while implementing the connection. Values of k1 to k6 are taken as per given by the instructor.
3.1.19 CBUSH connection is generated as shown in the image. @ surfaces are selected p1,p2 for the connection. Search distance is a user-defined value.	3.1.20 This is a bush element. Each of these having stiffness along 3 direction.
3.1.21 Some areas need to be modified in order to replicate the connection which is there in actual conditions. Like the window is connected with a sliding mechanism which allows the up and down movement of it. In order to replicate it, this modification has been done.	3.1.22 Here to avoid any further movement of the extended part has to be constrained.

4. Learning outcome:

Different type of connections and their use.

Different methods of generating a single connection.

Which type of connection is to be generated as per the requirement.

Understanding the mechanism and different parts in a door model.

5. Conclusion:

Understanding the Connections and importance of their implementation in different areas.

The connection has to be implemented depending upon the function of those 2 parts and need of any movement or not.

Some DOF has to be released in order to allow movement of the parts like the one which is done in the hinge connection of the door.

model link: https://drive.google.com/file/d/1yUoTdOByC0iVL8jGCi5P8d2SkQ3K_iwp/view?usp=sharing