Is there a difference between using initial conditions and adding a displacement/velocity?
Hi Ansys learning forum,
I was curious, what is the difference between, for example, adding an initial condition velocity, inserting a velocity, and inserting a displacement over a specific time interval?
Thanks
Best Answer

peteroznewman Member Posts: 11,073
An initial condition is set at time=0.
A boundary condition is enforced all the time.
Imagine a ball that is acted on by gravity pulling it down.
If the ball is given an initial condition of upward velocity, it will travel up, but slow down to zero then reverse direction as it falls back down due to the force of gravity.
If the ball is given a velocity boundary condition, it will continue to go higher and higher at a constant rate.
A ramped displacement D over the step time T is the same as a velocity boundary condition where V = D/T.
Answers
An initial condition is set at time=0.
A boundary condition is enforced all the time.
Imagine a ball that is acted on by gravity pulling it down.
If the ball is given an initial condition of upward velocity, it will travel up, but slow down to zero then reverse direction as it falls back down due to the force of gravity.
If the ball is given a velocity boundary condition, it will continue to go higher and higher at a constant rate.
A ramped displacement D over the step time T is the same as a velocity boundary condition where V = D/T.