Constraints on an Assembly

[voodoo333]

Here is an pic of what I am trying to simulate.

http://files.engineering.com/getfile.aspx?folder=f2064b24-cf07-4619-af14-ec3a3e03d2de&file=cam.jpg

I have a simple model of a metal cam rotating on a fixed s/s pin. A metal actuator is being pulled out of the cam causing it to rotate. A fixed plastic plunger is already in the cam stopping the rotation.

What I want to know is what actuator force I need to break the plastic plunger to free up the rotation.

I need to simulate with different materials and see how the different components interacts with each other. So I need to simulate this in the assembly - not seperatley.

to start:
Anyone help me on what type of constraint I should apply to the assembly?

Cheers

 

[kellnerp]

Break the problem into two parts.

1. What is the torque on the cam at the point it releases the actuator. (Also, at what rotation does this happen?)

2. What is the force on the actuator when it is just before the release position.

Looking at this as an FEA problem:

To solve 1) set your constraints up so that you have a time varying rotational displacement about the pin. Look at the torque reaction as a function of rotational displacement. Once you have that you can move the actuator in SW and determine the angle of release between the cam and actuator and then use the plot of torque to determine the force to solve 2).

To model the plunger/cam interaction, simplify your model to a plane model with line contact. If you can't do that, then do a pseudo plane model with a thin extrude of the cam profile and the plunger tip profile. I am not sure if Simulation will give you a spring element. If not use Cosmos/M or model a spring by judicious choice of cross section and modulus.

Constrain the plunger tip to move in a straight line. Constrain the end of the spring fixed. Constrain the cam to rotate about the pivot.

Use the soft spring option to get a solution in case you lose contact with the cam.

TOP
CSWP, BSSE

http://www.engtran.com

http://www.niswug.org

"Node news is good news."