We’re putting the final touches on our new badges platform. Badge issuance remains temporarily paused, but all completions are being recorded and will be fulfilled once the platform is live. Thank you for your patience.

Ansys Learning Forum › Forums › Discuss Simulation › General Mechanical › How to apply displacement derivative dependent force on bunch of nodes in apdl? › Reply To: How to apply displacement derivative dependent force on bunch of nodes in apdl?

July 13, 2024 at 4:56 am
Mehdi Baghaee
Subscriber

 

Thanks dlooman and mjmiddle. 

In my problem the load is both proportional to the derivative of displacement with respect to time and coordinate x, concurrently (F=dW(x,y,z,t)/dx+dW(x,y,z,t)/dt),where W(x,y,z,t) is the displacement of nodes in z direction in current time t.

It seems to me that COMBIN14 can be used for second term of my force (dW(x,y,z,t)/dt), but since in the first term the derivative is done with respect to coodinate x, using the chain rule :

dW/dx=(dW/dt)*(dt/dx)=dw/dt*(1/v)

which v is the velocity calculated in the previous substep. So I need to define the damping coefficient given by 1/v.

Is it true?

 

Â