Learning Forum

[AaronJackson21]

I am trying to model a mass that sits on top of a linear spring that is attached to the ground. The mass is then subject to a lateral acceleration such that the vertical spring bends and oscillates back and forth.

I have tried to use a single longitudinal ground-body spring under the connections tab, but the solution always ends up failing. What is the proper way to model this problem? Am I able to use a longitudinal spring that is subject to transverse loading?

[peteroznewman]

You need to draw the spring in the geometry editor (DesignModeler or SpaceClaim) as a spiral curve and assign a cross-section for the wire diameter.
In Mechanical, mesh that curve with beam elements. Apply a Fixed Support to one end and add a Point Mass to the other end.
You say you want to apply a lateral acceleration. Is that a constant acceleration or short duration acceleration that sets the oscillation in motion?
What do you want to know about the oscillation? If all you want to know is the frequency of oscillation, you would perform a Modal analysis.
If you want to know how far the spring/mass bends during the application of the acceleration pulse, then you would use Transient Structural analysis.
BTW, you posted in Explicit Dynamics, which is a specialized solver and the things I said above do not use that solver.

[Ram Gopisetti]

the procedure to work this problem is using the transient structural with the spring definitions (ground to body option) specify the stiffness and damping of the spring. the ground part will be fixed automatically for you. Now add an joint(body to ground> translation) and assign an joint load and select the type to be acceleration and use an function or your data to input the acceleration vs time. Use some substeps and solve the case. your tree will look something as follows . ( this method will works in the explicit to)
Cheers, Ram