Determination of Forces in Hydraulic Actuators

[struclearner]

For a dynamic simulation of a mechanism having an actuator (Hydraulic Cylinder) as a driver link, to determine the force required for a certain stroke, there are two ways to simulate the job,
1. Activating the mechanism by applying the force to piston and iterations of the force value to complete the stroke in a certain time.
2. Activating the mechanism by giving the motion to the translational joint for a certain displacement.
In the second case, where the force values required for actuator (Hydraulic Cylinder) to complete its stroke, will be determined, in joint of cylinder rod to supporting structure or in the joint of cylinder housing to supporting structure, is that one of the force, will be the same as required to actuate the cylinder. Theese Hyadaulic Cylinders are steering cylindres for turning of the vehicle.
These simulation will be done in ADAMS.

Thanks for input and clarification.

 

[GregLocock]

That seems an odd way to simulate a steering system. I suppose I have seen such a device on a very old 4wd tractor. Are you sure this is how your steering system works?

Also which product are you using?



Cheers

Greg Locock


New here? Try reading these, they might help FAQ731-376

http://eng-tips.com/market.cfm?

 

[GregLocock]

Here's how I'd do it.

1) using a frictionless road surface, slowly increase the force and measure the stroke of the pump
2) as 1) but at a higher ramp speed. This identifies damping in the system
3) as 1) but using the correct friction model at the contact patch
4) as 3) but with a forward velocity on the vehicle.



Cheers

Greg Locock


New here? Try reading these, they might help FAQ731-376

http://eng-tips.com/market.cfm?

 

[struclearner]

Thanks for your reply Greg.

The simulation is being done in ADAMS View. The objective is to determine the force required for turning of a vehicle using hydraulic steering system. The first simulation is for static turn when vehicle is standing still.
My original question remains unanswerd, that is to find out the forces in the supporting joints, what will be the best way to actuate the mechanism, the best way is by specifying the displacement based motion or by applying the force and doing the iterations to determine the magnitude for a stroke in a certain time.

 

[GregLocock]

I have suggested one way of doing that. "slowly increase the force and measure the stroke of the pumpram"

Cheers

Greg Locock


New here? Try reading these, they might help FAQ731-376

http://eng-tips.com/market.cfm?