UG Simulation_applying Vector Force

[jschetl9]

HI,
I am trying to apply vector force(unit force) at one end of the simulated 4-barlink mechanism. I used Revolute+Revolute+Universal and Ball joints at each end.
Grubler count is shwoing 0 and the dof also zero (with driver on one of the revolute joints).
Now when I apply unit vector force, when I run the for excel map the simulation is giving a torque of 0.9psi where as the FBD free body diagram gives an end torque of 8.63psi.
Pl guide.
Thanks
Srini

 

[cowski]

Torque measured in pounds per square inch? Something sounds wrong here...

 

[jschetl9]

Oops,my mistake: Lb-in

HI,
I am trying to apply vector force(unit force) at one end of the simulated 4-barlink mechanism. I used Revolute+Revolute+Universal and Ball joints at each end.
Grubler count is shwoing 0 and the dof also zero (with driver on one of the revolute joints).
Now when I apply unit vector force, when I run the for excel map the simulation is giving a torque of 0.9Lb-in where as the FBD free body diagram gives an end torque of 8.63Lb-in.
Pl guide.
Thanks
Srini

 

[cowski]

Can you post a sketch of your mechanism?

 

[jschetl9]

Pl find the attached sketch

 

[cowski]

Ignoring friction, and in the position shown in your sketch, I get 9.2 in lb torque in joint C.

You refer to the ground joint as the 'driver'; are you applying any force to this joint, or only the unit force at the end of link 1? Are you simulating a range of motion or just this one position?

 

[jschetl9]

I am applying force at the end of link1 and simulating a rnage of motion. for ex: from displacement -10 to +10 with a velocity of 1.