How can I calculate the reaction forces of a torsion spring on a wall?

[coldadler]

Hi guys,
I am working on design where I am using a torsion spring. And I need make an analysis and see the deflection of the walls. How can I calculate the forces that applied from Spring's legs to walls.

Thank you all in advance.

 

[Baluncore]

Welcome to PF.

I expect the spring leg will become slightly curved, and that the wall will be dented slightly.
You will probably need to better define the contact points of the spring and legs with the wall.

 

[Lnewqban]

What do you mean by deflection of the walls?
Do you know the RPD (rate per degree) of this spring?

 

[JBA]

We need to see a side view of the assembly to understand how and where the two walls are supported along their lengths.

 

[coldadler]

Welcome to PF.

I expect the spring leg will become slightly curved, and that the wall will be dented slightly.
You will probably need to better define the contact points of the spring and legs with the wall.

First of all Thank You.
You're right, contact points will be different than that. But I need to make a calculation on this conditions.

What do you mean by deflection of the walls?
Do you know the RPD (rate per degree) of this spring?

I'm making CAE Analysis at Catia and I want to see the wall deformation which happens at set and full stroke positions of springs (under load). To make this analysis I need the enter the force values. But I'm not sure how to calculate it.
I have the values of springs, I know the Torque values under this positions but how can i find the leg's reaction forces?

One of my colleague said we need to take the torque value as a spring reaction force and we need the apply this force to walls. ?

We need to see a side view of the assembly to understand how and where the two walls are supported along their lengths.

I attached one more pic. I hope I could show it clearly.

 

[Baluncore]

You do show a local point contact for F2 on the green.

F1 will not be spread over the length of the leg as you show.
You need to provide a local point of contact for F1 on the yellow.
If necessary provide a bump of yellow to contact the end of the leg.

You must also consider which (three?) points of contacts hold the coil of the spring in place.
That may be F3 where the coil touches yellow material.

 

[coldadler]

You do show a local point contact for F2 on the green.

F1 will not be spread over the length of the leg as you show.
You need to provide a local point of contact for F1 on the yellow.
If necessary provide a bump of yellow to contact the end of the leg.

You must also consider which (three?) points of contacts hold the coil of the spring in place.
That may be F3 where the coil touches yellow material.

But when I make analysis I only give forces at contact points to see the deflection. I clamp the green part and I specify the rotation axis of yellow part and forces that applying on the part and it's show me the results. I don't even put spring into analysis, I only give forces. But in this case I don't know the forces. How can I calculate the spring leg's reaction forces that applied to walls under the load? Dividing the spring torque into leg length will give me the true result? And you are right, at coil contact point there will be F3 force.

 

[Baluncore]

The helical spring generates a torque. The force F1, applied by the spring leg to the yellow wall will depend on the distance from the spring axis, or maybe coil contact point.

The force applied to the yellow wall by that leg will become a torque about the centre of rotation of the yellow wall.

Unfortunately the spring and wall do not share a common axis of rotation, and the contact line is not truly radial about either centre. Therein lies the complexity.

If you reduce the spring leg to contact the yellow wall at only one point on the wall, then the problem becomes tractable.

 

[Lnewqban]

...
I'm making CAE Analysis at Catia and I want to see the wall deformation which happens at set and full stroke positions of springs (under load). To make this analysis I need the enter the force values. But I'm not sure how to calculate it.
I have the values of springs, I know the Torque values under this positions but how can i find the leg's reaction forces?
...

My humble suggestion:
Application of $F_2$ seems to be the weakest link, according to your last schematic.
If you have the value of torque for the spring at maximum deformation (200-75 degrees), then:

$F_2=Max~torque/L$

The wire will slide respect to the points of contact of $F_1$ and $F_2$ as the mechanism moves, reason for which those surfaces will need some form of lubrication.
The other important thing is to loosely restrict movement of the coil, which will tend to rotate and relocate itself when supported by $F_1$ and $F_2$ only.
The diameter of the coil will decrease some when compressed.

Please, see:
https://www.thespringstore.com/coil-torsion-spring-calculator.html

http://www.faculty.fairfield.edu/wdornfeld/ME311/AssocSpringBarnes-SpringDesignHandbook.pdf#page106