topic Re: The Total Reaction Force in Simulation Mechanical Forums (Read-Only)

The Total Reaction Force

Anonymous — Mon, 23 Apr 2012 17:47:04 GMT

Hello, everyone

I am working on an static linear stress model. I want to know the total reaction force on the boundary condition, this should be a very common engineering problem. However, the instructions from documentations are not straightforward enough for me. Can anyone tell me how to get the total reation force from the boundary condtions to the structure?

Thank you.

Re: The Total Reaction Force

S.LI — Mon, 23 Apr 2012 18:45:38 GMT

You need to do a little bit of work to get the total value.

1.) show reaction force in result tab;

2.) select all nodes on the boundary that you are interested in;

3.) inquire results and select "sum" at Summary.

Re: The Total Reaction Force

Anonymous — Wed, 25 Apr 2012 19:49:54 GMT

Thank you. I did get the reaction force by doing so. But, still, I failed to get the reaction moment using the same mathod. Is there something I need to do?

Re: The Total Reaction Force

S.LI — Wed, 25 Apr 2012 20:00:01 GMT

In one of my previous posts, I explained how reaction moments work in ASIM.

Reaction moments in ASIM are only provided on rotational DOFs, such as beam, shell elements.

If you do want to sum all reaction moments on these rotational DOFS, I'll be surprised if it doesn't work.

Currently, ASIM could not calculate reaction moments from reaction forces by timing them with distances.

Re: The Total Reaction Force

John_Holtz — Wed, 25 Apr 2012 21:26:24 GMT

So to elaborate on S.Li's suggestion, you need to perform the calculation of the moment about the point or axis of interest: M = r cross F where r and F are vectors. Use the "Save Values" button on the Inquire Results window (shown in earlier post) to output the reaction forces and coordinates of the nodes, import that file into a spreadsheet, and do the above calculation.

The command "Draw > Design > Centroid Creator" in the FEA Editor will help you find the centroid of a surface, in case that is where you want the moment.