## Applying bearing forces

## Applying bearing forces

(OP)

Hi All!

I am new to Abacus, so maybe this question is trivial, but anyway...

From other FEA packages I am used to being able to select faces of my geometry and apply forces to it. This force is usually distributed across all mesh nodes on the selected face(s) so that the total node forces sum up to my specified force.

I can't seem to figure the equivalent steps in Abaqus/CAE.

Concentrated loads apply only to vertices, and if I specify all vertices on the surface I want, the force is not distributed, instead it is applied in full at each point, making the total force = my specified force times the number of points. Not what I want. If I divide my specified force with the number of vertices I get the correct total force, but unnecessary high local stress around the vertices since the load is only applied at one mesh node. Not good either.

If I use a Surface Traction load I get my force distributed across mesh nodes, but now I have to calculate the surface pressure from the force I want to apply and the surface area. I know I can get the areas from Tools > Query, but it gets very cumbersome when the force is distributed across multiple faces.

Am I missing something? Is there a smarter way to do this?

/C

I am new to Abacus, so maybe this question is trivial, but anyway...

From other FEA packages I am used to being able to select faces of my geometry and apply forces to it. This force is usually distributed across all mesh nodes on the selected face(s) so that the total node forces sum up to my specified force.

I can't seem to figure the equivalent steps in Abaqus/CAE.

Concentrated loads apply only to vertices, and if I specify all vertices on the surface I want, the force is not distributed, instead it is applied in full at each point, making the total force = my specified force times the number of points. Not what I want. If I divide my specified force with the number of vertices I get the correct total force, but unnecessary high local stress around the vertices since the load is only applied at one mesh node. Not good either.

If I use a Surface Traction load I get my force distributed across mesh nodes, but now I have to calculate the surface pressure from the force I want to apply and the surface area. I know I can get the areas from Tools > Query, but it gets very cumbersome when the force is distributed across multiple faces.

Am I missing something? Is there a smarter way to do this?

/C

## RE: Applying bearing forces

corus

## RE: Applying bearing forces

## RE: Applying bearing forces

As corus mentioned, we usually calculate the pressure on the surface by known force and area. P=F/A. But, this pressure is assumed to be applied vertically on that surface. Sometimes, if the applied force is not exactly vertical or horizontal direction, but at an angle on the surface, how can we convert the forces (F cos (alpha), F sin (alpha) ) into pressure on the same surface?

## RE: Applying bearing forces

Alternatively, apply a pressure load to the face, and use a python expression to define the spatial distribution of the load. (The same is achieved using the DLOAD subroutine, but the Python expression is MUCH simpler)

## RE: Applying bearing forces

When I create the distributing coupling, which constraint control point should I select, any point on that surface? Also, which weighting method should I choose? uniform?

I work on the Lug hole of the casting body, the surface to be applied force is curve, should I select the point of the centre of the lug hole (How can I choose in geometry)? or any point on the curve surface.

Thanks.

## RE: Applying bearing forces