Learning Forum

[nsaklani]

In the following geometry, a revolute joint is provided as shown. The connection between body 1 and body 2 is frictionless. An upward displacement is applied on body 1 and a downward force of 4.0386*10^7 is also applied. The force reaction (at the applied displacement) and total deformation plots are shown. My question is at 0.4 s, the displacement is 0.043m while the force is 3.261*10^7. Clearly the body will not move at this force or conversely to displace the body by 0.043m the applied force has to be greater than 4.0386*10^7. Can anyone explain what is the meaning of intermediate values in the result?

[peteroznewman]

A Static Structural model that has an applied displacement is an enforced condition and the nodes will be moved by that amount. The force required to enforce that displacement is calcuated in the solution.

Your statement “Clearly the body will not move at this force” is wrong for this model.

The way you have applied the displacement is not realistic because the surface it is applied to has to remain horizontal. A more realistic way to model the lift of that end is to use a Remote Displacement that would allow the surface to rotate with the rest of the part as the Pilot Node at the center of the surface is moved by the value in the Y displacement field.

Intermediate values in Static Structural occur because loads are ramped on over time. If Step 1 ends at 1 s then at a time of 0.4 s, 40% of the load for Step 1 has been applied.