RBE2 adds infinite stiffness to attached nodes which means both nodes to exactly the same displacement whereas RBE3 is an interpolation element and distributes the loads and the mass depending on the length. Depending on the application one of these rigid elements should be used.
Hi zerodof,
I was looking at the ACMODL, I did not use it before as our nastran decks are slightly different and as we are using AKUSMOD. I am not sure if you have the any kind of guide, but I am using quick reference quide and the format is as follows,
1 2 3 4 5...
I use RBE2 elements for simulating bolts. And constrain all 6 dofs. RBE3 actually distributes the forces to the connection points by inversly propotional to the RBE3 element length. So I would not prefer using RBE3s. Depending on the stiffness of the materials, only rotational dofs can be...
I have been working on similar things for about a year now. One thing I want to point out; I understand that you want to fill and couple the air with the BIW structure. I use akusmod (msc software) to generate air. However, you should need a trim body model in which no openings are available and...
I have realized something. Actually, I want to hit the middle point and want the other nodes to depend on the center point. In this case, exactly the reverse is happening. So I guess the weighting at the center should be 1 and the rest should be some other value close to zero. However, the...
This is a bracket that holds(carries) the driveline shaft. Bracket is a circular piece and the shaft passes through the bracket and there is rubber between the shaft and the bracket. I am doing a point mobility analysis. Only the parts on the exterior side of rubber is modeled. So, in the model...
I am trying to model a distributed load for Nastran analysis. The shape is a hollow cylinder covered with rubber from inside. I have no idea about the rubber stiffness properties and thats why I ingore the rubber part and would like to use RBE2, RBE3 or some other element to simulate the force...
I am trying to find the direction or coordinates of TRA. Lets say you have an engine and have all the properties including mass, com, inertias and directions. How can I find the coordinates or direction cosines for TRA?
If I have the inertia, inertia axis and mass properties of an engine, how can I calculate the roll axis when a torque in some direcion (which I have the data for) is applied ?
