Learning Forum

[babri123]

Hi

I want to model a double beam element in ansys workbench for modal analysis and achieving natural frequencies of this system

the system has turning spring and transverse spring at endpoints A and B and k is the spring stiffness per unit length that connects beam1 and beam2 to each other. 

I don't know how i can model it in ansys workbech modal , can anyone guide me to do this ?

i want to model the

[jj77]

One way could be to use beam elements for the beams 1 and 2 and spring elements for the elastic layer - ideally use say quite a few element per beam in order  to have  many springs. (BEAM188 and say COMBIN for springs)

 

The other way is to model it with other elements.

[peteroznewman]

Create two beams in SpaceClaim. This is easily done by constructing a solid beam on the Design tab, then on the Prepare tab, use the Extract tool.

In Mechanical, add Bonded Contact between the line bodies.  Set the Type to Beam.  You have to type a beam radius. You will have to calculate the radius you need to get the required value of k.

Is this a strictly 2D analysis?  If so, add a displacement BC to keep the beams in the plane.

Add the required springs to ground at each end.

Here is the image that shows the long beams with the short beams that connect it at each node.

Beams are not the same as springs, because springs connect with no rotational stiffness at each end, while beams connect with rotational stiffness.

I used Bonded Contact to minimize the effort to build the model. If you want springs, you will have to do more work.