Learning Forum

[RHYLANE]

Hello all, i'm trying to analyse the vertical deflection of a beam traversed by a point load as shown in the figure. The load has the following format: F=Pcos( ωt+ϕ) where P is the load amplitude (N), ω is the radial frequency of the applied load (rad/sec), V is the speed of the moving load (m/s) and t is the time (s). ϕ is an initial phase applied to the load to ensure that for every frequency, it will arrive at the mid-span with maximum amplitude. Please guide me, how would I define that in Ansys workbench?

[Erik Kostson]

Hi

Not sure, but the below approach might help.
Perhaps use a thick block on top of the beam to transfer the load with onto the beam (via a frictionless or no separation contact say - frictionless transfers only compression to the beam and no separation transfers both tension and compression of the sinusoidal force). Use then a remote displacement to translate that block on top of the beam and a force that can contain a sinusoidal variation - also use transient dynamic if that is important (the below schematic setup is just for reference just to show a possible way of doing this)
Or even easier and better is to take away the force and use an enforced sinusoidal displacement (just tune the magnitude to get the correct force) since that will be much easier to get to converge (sinusoidal force will be an issue if we have frictionless contact, force will though work ok with no separation contact).


All the best

Erik

[RHYLANE]

Dear .

Thank you so much for your reply.

I am new with Ansys Workbench. So I am still not get your point.

I added a simply supported beam but I didn't know how to define the moving harmonic load.
I think that I shoud use the transient analysis since i need to obtain the variation in time of the vertical displacement of the midpoint of the beam. The problem is how I can define the harmonic moving load.

Thank you for the help.

Rhylane.

[Erik Kostson]

Hi

There is no moving load in Ansys so we can not just use a simple load to what you need:

so what we are saying above is that one way to do what you need is to do as I described. So if you have modeled with Ansys for a while and you get familiar with the basic use of ansys mechanical then you will understand the set-up that I am showing above, which is pretty basic I would say.

Now to get up to speed for modelling with ansys, and so you can perform the analysis we described above, see our courses which are free to take.

The courses that are relevant are are basic modelling (getting started), contact modelling and transient dynamics.
Once one has taken these courses and understood the contents, one should in principle/in theory to model what we have described above and shown again below.
Perhaps use a thick block on top of the beam to transfer the load with onto the beam (via a frictionless or no separation contact say - frictionless transfers only compression to the beam and no separation transfers both tension and compression of the sinusoidal force). Use thena remote displacement to translate that blockon top of the beam anda force that can contain a sinusoidal variation- also use transient dynamic if that is important (the below schematic setup is just for reference just to show a possible way of doing this)

All the best and enjoy your studies.

Erik