Week 6 - Creating connection for Rear door

                                                                                     Creating connection for Rear door

OBJECTIVE

• To give different types of connection for rear door model of car
• These connections are given to the model using ANSA in NASTRAN deck which will be used later for NVH simulation

Door Assembly is very important model in the car as it consists of different types of connections representations .Different mechanism are also present in the door assembly model like door lock mechanism hinge mechanism  glass  slider mechanism and latch mechansim .

METHODOLOGY

• Import the meshed model
• Assign the Property ID for different regions
• Identify  different mechansim and assign various connections for door model

PRODECURE

• Import the model before assigning connections for the model once observe the real car model as it  gives idea for the different types of connections used for various mechanism

                                         

• Assign different PID for glass and the parts which are needed to be welded

• We  use different kinds of connections 
• RB2 rigid  is simply used to rigidize the hole .This type of connection is used where there are no bolts the nodes using loop selection .After selecting all the slave nodes a master node will be formed which connects all the slave nodes

   

• Zone Cut   It is used when an area must be rigidized at a particular region .This region acts a washer element during simulation .Therfore  this type of connection is used where bolts exist.One must click on the edge of the circle using loop selection then the whole circle will be selected .Then specify the offset value .Now some area will be reconstructed using the existing mesh parameters in order to form zone cut

      

• Now use elements RB2 many nodes select the egion using poly line selection in order to select all the slave nodes easily .Then RB2 connection is deployed along with zone cut

                                                                                 

• Cluster   This connection is used when a manual bolt connection must be deployed beween two or more surfaces
• For automatic bolt connection one must follow steps  create COG  for the hole COG is basicially a 3D point convert this 3D point  now open connections manager  and select the bolt symbol which has created in earlier step  then assign  p1 p2 p3 select FE type as bolt and give the required values and constraints apply and then realize the connection

                                              

• Hinge connection  must be constarined to only five degree of the freedom as this allows the door  to open

                                                                     

• Spot welds are also parts of connections .In ANSA spot weld can be deloyed between different surfaces .Create curve convert  curve to spot weld  then open connections manager and select the spot weld curve and then assign p1 p2 p3
• Mostly overlap shell is used when the surface are parallel  and y joint shell is used in perpendicular surfaces

     

• Spot weld using RBE3    Create COG  convert COG to spot welding point  use connection  manager to generate  RBE3  HEXA RBE3

                                                                     

• CONMi   It is referred to as con mass. It is basically a concentrated mass  connection where a point is created for representing the weight of it .We must give the mas tonnes .

                                                       

• CRUSH connection    This connection for the glass is always given in closed . Create curves using perimeter curve option which is available in mesh mode .Then convert those curves to seam lines .

                               

• Generated RBE3  connection has its own local coordinates which are different from each other .This could create some distrubance during simulation . So we need to convert all the CBUSH coordinates to global coordinates .This can be done by changing the CID  value to  properties
• We can change all the CID values in a single shot using modify option

                   

• Atmospheric strip  can be assigned in ANSA  create curves using perimeter .Then convert those curves to seam line .This acts as a  rubber strip during simulation White line in the below  indicate rubber strip

                                                                               

CONCLUSION

In this  i deployed connection with RB2 and RB3 elements  successfully .Constarined  the hinges to degree of freedom .Learned different  concepts regarding tailored cut Learned  all types of connection in ANSA

OUTCOME

• Assigned various connection according to the required mechanism 
• Learned and implemented all the connection in ANSA
• Studied different real life concept about connection in car