Position dependent loads in dynamic simulation?

[dr849310]

Hello all,

    I am trying to do an analysis of a pump in which the loads acting on the piston face switch direction halfway through the cycle (pushing the fluid out and sucking new fluid in)  I have been trying for quite some time now but is there a way to set up the external loads in the simulation such that the external force acting on the piston switches direction according to the position of the crankshaft? or according to the velocity of the piston maybe?

Please advise,

Thanks

Dylan Rhodes

[JDMather · Accepted solution]

There is an example of exactly this problem in the Wasim Younis book.

Set an If-Then rule based on velocity of the piston (Prismatic Joint).

Attach your assembly here if you can't figure it out.