Week 6
AIM : to perform connections in the necessary areas and perform analysation in the given FE model in ANSA
Procedure : FE rear door model is imported.
BEFORE CARRYING OUT CONNECTIONS :
geometry check is done.
a model consists of different connections. connections are done between two or more components to form a single final component. components of a model can be attached by different connections. for example two metal components can be joined by using nut and bolt or welded together.
studying about the connections and to deploy proper type of connections is done in the model. before doing connection processes , properties has to be set for different components seperately.
Types of Connections used -
Bolt
Spot weld
Hinge
CBUSH
Bolt
Bolt connections can be deployed by using nastran-rbe2-many nodes.
Selection of nodes in a part where bolt has to be done is executed. it can be done by using entity or feature or loop.
Bolt connections have to be done where we could see bolt holes and also where two different bodies get attach to each other. If the more than two surface lie parallel to each and lie on same plane , then COG point has to be set. topo-points-CG is used. converting the three D point is done by selecting convert and it is converted into bolt. after doing the above process , we need to go to the connection manager and select bolt in box. Setting properties (P1-P3) is done and by using bolt connections , we could obtain the necessary connections.
Spot weld
It is done to join two surfaces through a weld. It is done when we cannot use bolts to connect the parts. Also this increases stiffness compared to bolts. first we need to generate a 3D point . topo-points-on COG. It is done to mention center of gravity of a particular component as the load that is acting on it get constrained at point where overall mass is constrained. so carrying connection helps to achieve more stiffness.
after producing 3d point it is converted into spot weld and by selecting connection manager the connections are deployed. they are made by firstly selecting the property(pressing F1 key) where the spot weld has to be done. second by opening the rbe3 hex rbe3 , we need to check the necassary selection methods. search distaance , fixing 6 degrees of freedom in rbe3 pinflags and selecting property id has to be done. after doing the above process, a spot weld will be generated .
CBUSH
This is carried in the sides of window regions . A spot weld and bolt connections cannot be used to fix a windows properly as they are adjusted according to the users. In this case cbush is deployed so the bush like connections are produced and makes it get fixed properly and also makes it easier to glide.
to generate this connection , we need to use mesh-perimeter-feat to curve option. by selecting the sides a curve is generated . By going to convert , the curves are converted to seam line. by selecting the generated line , connection manager is opened and rbe3 cbush rbe3 is selected . properties are set just like spot weld accordingly. mentioning search distance and selecting down the pbush id and giving apply and realize , generates pbush connection. stiffness value has to mentioned while setting pbush id. it is set for 6 degrees of freedom.
Hinge
It is arried when movement in z axis is absent. rbe2-two nodes is used. After executing bolted connections , the central nodes of two different connections are selected to generate a hinge. Here the degrees of freedom is set to 5. It is done in the sides of door.
Spot weld
CBUSH
Bolt
Learning outcomes
Learnt about how different types of connections can be deployed
Conclusion
Connections were made in the given rear door model accordingly.