How to simulate a spring release system

Good morning to everyone,

With my model, the target is to simulate a system quite strange: i have a spring that is normally locked that is able to act on a shaft and a lead screw system (so the translation transformed in rotation) and when thi spring is released, must be able to win a load of 500 N.

My target is to try to estimate the force of this spring sufficient to win the 500 N load for a space that should be 6 mm. This load is applied directly on the screw, not on rotating part.

I'm struggling with the solution, i think i'm making some in mistakes: i don't know how to simulate the release of the spring, so like a ramp force, and also how to simulate a load that is linearly decreasing from 500 N up to 10 N in 6 mm.

The problem is that in the leadscrew system i have like output the rotation of the nut, but is not my case because i need the force applied on the screw also after the nut.

In addition, the leadscrew block forces me to have force applied on the nut, and torque applied on the screw. Do you know if it's possible to reverse them?

Thanks for the attention.

[Ted Shultz]

How are you doing this? Is this in simulink? Can you show what you have so far?

[Andrea Ongaro]

I'm using simscape.

As you can see, my first idea was to use a ramp to represente the spring force, and on the other side a torque that is equivalent to the 500N load that is applied on the nut.

Here the problem is that the real system has the load applied directly on the continuation of the screw, the nut is just the connection point with another part of the transmission.

In addition, i don't know if the system also represented in this way, is physically correct: what i want to verify is that the force of the spring is enough to win the load for a space that is 6 mm, using the position sensor.

Answer 1

[Steve Miller]

To lock and unlock the spring, use Loaded-Contact Translational Friction model. To measure the force, put a Force Sensor in series with the element whose force you wish to measure. I have attached an updated model that shows that once the spring is unlocked, the spring is compressed 6mm and is providing 500N of force.

[caio falcão]

Hello steve, do you have any idea on how can i simulate this kind of compreesing and releasing of the spring that are shown in this video? I have all the paremeters masured, all the informations needed but I am stopped in this simulation.

https://www.youtube.com/watch?v=iKzrotoDt7w

Hope that you can help me, thanks a lot.