finding force

[Assis As]

how can i find force required force to move upper platform at lowest and highest position.

[matt]

how can i find force required force to move upper platform at lowest and highest position.

You should be able to do this with a simple free body diagram and a little trigonometry, without the software. At least to make sure the software is giving you the right answer.

Do you have values for the cylinder force or resistance?

[Assis As]

thank you for reply , i do not have values of cylindrical force , i want to find it so that i can go for trigonometry. How can i find it

Thank you

[matt]

thank you for reply , i do not have values of cylindrical force , i want to find it so that i can go for trigonometry. How can i find it

Thank you

Do you know how to make a Free Body Diagram?

[Assis As]

this is diagram related to hydraulic cylinder

[MJuric]

thank you for reply , i do not have values of cylindrical force , i want to find it so that i can go for trigonometry. How can i find it

Thank you

I could be mistaken because I haven't tried to actually figure this particular problem out but I don't think you need trig at all. Should be able to do this with straight up addition, subtraction and division.

Find the pivot point of your CG of your rotating mass at the position you want to find the load for.
Find the torque load from the CG (Multiplication)
Find the load at the cylinder by dividing the previous answer by distance of the cylinder CL from the pivot point.

[matt]

You have to figure the components of the cylinder force in the axis of the vertical member and perpendicular to it. For that you need some simple trig.

And you want the FBD if you cut the mechanism in half with a vertical line. You want the horizontal force at the top joint. Is that right?

[Assis As]

i got it , if i want to find force in solidworks how can i go for it ???

[matt]

i got it , if i want to find force in solidworks how can i go for it ???

I would multiply the horizontal length of the angled cylinder by the cylinder force and multiply/divide that by the lever arm ratio. The horizontal length of the angled cylinder does the trig for you. FBD is the best way to keep track of all of that. Horizontal and vertical components of force at every joint or cut.

[MJuric]

You have to figure the components of the cylinder force in the axis of the vertical member and perpendicular to it. For that you need some simple trig.

If you want to do it all by hand, yes then some trig is required. If you want to do it the easy way just add the cylinder to the parts you find the CG of in Solidworks.

And you want the FBD if you cut the mechanism in half with a vertical line. You want the horizontal force at the top joint. Is that right?

Not following this question. The "Forces" are the cylinder and gravity. Gravity acts on the CG and the cylinder is linear at the cylinder. Those are the only forces you need if you're trying to figure out how much cylinder force is necessary to counteract the load force.

[matt]

Not following this question. The "Forces" are the cylinder and gravity. Gravity acts on the CG and the cylinder is linear at the cylinder. Those are the only forces you need if you're trying to figure out how much cylinder force is necessary to counteract the load force.

The cylinder is angled, so there is a vertical and a horizontal component to the force. It compresses the vertical bar at the left to some extent.

[MJuric]

i got it , if i want to find force in solidworks how can i go for it ???

You could do it in a simulation of you wanted to, but unless you're doing it as a project I'm not sure why you would go thru that to do something you can do in a few math problems.

To do it in a simulation you could, fix the base, place your cylinder rod against a stop in the cylinder body and apply gravity. This is all going from memory but then you can find the force at the end of the cylinder rod. Change the position of the stop or length of the rod to change positions and rerun the sim.

[MJuric]

Not following this question. The "Forces" are the cylinder and gravity. Gravity acts on the CG and the cylinder is linear at the cylinder. Those are the only forces you need if you're trying to figure out how much cylinder force is necessary to counteract the load force.

The cylinder is angled, so there is a vertical and a horizontal component to the force. It compresses the vertical bar at the left to some extent.

Converting that force to a torque includes both of these forces. CG*distance from pivot = a torque. Torque/Cylinder distance from pivot = linear force of cylinder necessary to counteract force of CG torque.

The cylinder can only put out a linear force so there is no sense in figuring out the horizontal and vertical force at the connecting point unless you want to look at the stress on the connector. That however is a different question that the one I think you posed in the OP.

[matt]

The cylinder can only put out a linear force so there is no sense in figuring out the horizontal and vertical force at the connecting point unless you want to look at the stress on the connector. That however is a different question that the one I think you posed in the OP.

Yeah, but you have to find the horizontal component to find the torque, and you don't need the torque to solve the problem. The horizontal component of the cylinder force and the lever arm lengths are what affect the force he's looking for.

[MJuric]

The cylinder can only put out a linear force so there is no sense in figuring out the horizontal and vertical force at the connecting point unless you want to look at the stress on the connector. That however is a different question that the one I think you posed in the OP.

Yeah, but you have to find the horizontal component to find the torque, and you don't need the torque to solve the problem. The horizontal component of the cylinder force and the lever arm lengths are what affect the force he's looking for.

Why do you need the horizontal component to find the torque? The torque created by the CG is the vertical force @ the horizontal distance from the pivot point. The necessary force at the cylinder is that torque divided by the distance of the centerline of the cylinder from the same pivot point. The two torques are equal when the system is in equilibrium. Am I missing something?

[Assis As]

"To do it in a simulation you could, fix the base, place your cylinder rod against a stop in the cylinder body and apply gravity. This is all going from memory but then you can find the force at the end of the cylinder rod. Change the position of the stop or length of the rod to change positions and rerun the sim." please i need little more explanation

[MJuric]

"To do it in a simulation you could, fix the base, place your cylinder rod against a stop in the cylinder body and apply gravity. This is all going from memory but then you can find the force at the end of the cylinder rod. Change the position of the stop or length of the rod to change positions and rerun the sim." please i need little more explanation

You'd be better off going thru some of the Simulation tutorials because what I said was the "Cliff Notes" version at best.

[SPerman]

In theory you can do this using Motion Analysis. I tried it on a more complicated assembly and the results were suspect.

[Assis As]

thats nice going to try it .Thank you very much