Learning Forum

[YeonHwi_Jeong]

[bhagwantP]

Please verify units are set properly. One common mistake in the Engineering Data tab is to have the units set to Pa when you are typing a value in MPa or psi so you can end up with values that are 1 million times too flexible.
For beam models, you can type cross-sectional area properties that are too small by a large factor.
Either or both of those errors can result in a force creating an enormous deformation.
It is also possible to have the units set to the wrong value when creating the force.

[peteroznewman]

When you solve a model with Large Deflection turned OFF, you are making the small angle assumption. That assumption means that nodes travel in straight lines as shown by the green arrow labeled Initial Direction. They do not rotate around arcs. If the angle of twist is not small, you must turn on Large Deflection so that nodes can travel along an arc and not travel in straight lines.
Once you turn on Large Deflection, the model becomes nonlinear and requires much more time because you have to solve with many small steps to accumulate the deformation that allows the nodes to follow an arc path instead of a straight line. The issue with your model is the beams are so long that they buckle before the full moment is applied. Do you need to do this analysis with the full length of the beams?