# how to calcualte total reaction force in a plane in ABAQUS

Dear all,

This is my first post in iMechanica forum.

I am trying to some simulation of cantilever beam bending in abaqus. Since the aspect ratio is pretty low (height/diameter~=2), I use 3D solid element instead of 2D beam element to construct the beam. I set the deflection at the free-end as the boundary condition, and try to solve the reaction force (perpendicular to the beam longitudinal axis). But I get in trouble to calculate the total reaction force at the free-end.

I know abaqus can do some operations on existing output data. I tried to sum the reaction forces of all nodes in the free-end plane, but the result did not agree with the Timoshenko beam equation.

If anyone can give some suggestions, that would be great.

Thanks in advance.

Ping Du

## There could be hundreds of

There could be hundreds of reasons why you are not getting the correct answer.

At first check if you are properly recovering the total reaction force: just load the beam model at the end using a vertical force instead of using a prescribed deflection and recover the total reaction.

Wieslaw

## Use a Coupling Constraint

A Coupling Constraint couples the motion of a surface to the motion of a single point, which is the reference point. Clamp the reference point. The reaction is all concentrated at the reference point.

Echeban

## force sum

I have the same problem,do you understand what to do?

## Are you sure that you have

Are you sure that you have a sufficiently refined mesh; i.e., you're getting converged solution? Also note that Timoshenko beam theory is for thick beams, but that doesn't mean you can use it to solve a solid section (e.g. cube that can also be said a beam with aspect ratio = 1). So check your problem parameters and make sure you are satisfying tenoshenko beam theory assumptions (to a reasonable extent).

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