Learning Forum

[engr.rohan7]

Hello community, I am trying to run a coupled field transient analysis for brakedrum. I've defined joint forces and thermal loads on brakedrum and I've also defined a couple of frictional contacts alongwith bonded contacts. Following are the screenshots for the contacts and structural and thermal loads. 

1) Contacts:- Frictional contact

The offset in the geometric modification field is defined after determining the gap using the initial info from contact tool.

2) Joints:

a) Translational joint 

b) Revolute joint 

I have also created a contact tool, for which the initial information is as follows,

3) Loads are as follows,

a) Convection on brakedrum 

4) Convection on brakepad 

5) Radiation on pads 

6) Joint load- force, on brakepad

Similarly defined for other brakepad.

7) Joint load- rotational velocity 

]

 

As per the video tutorial for thermomechanical analysis of disc brake by Ansys, I've also created command snippets for contacts and transient analysis

For contacts-

 

For transient analysis-

 

I would like to know whether the above defined contacts , loads and boundary conditions are correct.

Looking forward to your reply.

Regards, 

Rohan.

 

[peteroznewman]

This site shows how drum brakes operate. Pads are on shoes that pivot about one end and are actuated by a piston at the other end. A fairly accurate simulation of this design would be to put the pads on shoes and use a joint on one end to create the pivot and a force on the other end to push the pad against the drum. 

Your model has pads connected to ground by a Translational Joint which creates a slightly different motion than pivoting the pads about one end. Your model has no shoe so the pad are defined as either Rigid or Deformable.  Which one did you choose?  Each one introduces some error relative to modeling the shoe.

Pads conduct heat to the shoe so it is inaccurate to have convection or radiation heat transfer from the inner pad face.

It’s fine to make an initial model that idealizes the mechanism to make a model that is quicker and easier to simulate. Just be aware that a real brakedrum is more complicated than that.