hello evryone, i’m a new user of simscale plateform, i wish to know how to define a function of an harmonic force like a BC, just for you to know, i wish use the simplist harmonic force like f(t)=A*sin(2Pi*fr+phi) where fr is the frequency and phi is the phase.

thanks.

# Harmonic analysis

**ShoX**#1

Dear ShoX,

Welcome to SimScale! you can easily give this formula as a load function in the force load boundary condition. The formula should look something like this: **(some value).sin(2.pi.f)** (please replace ’ . ’ with ’ * '). The phase can be changed by a phase change option below in the boundary condition.

You can have a look at this project for more info.: Harmonic analysis of an impeller *(Please have a look at the ‘excentric vibration force’ in this example)*

In case of any question/s, feel free to ask.

Best,

Ahmed

**ShoX**#3

thank you very mush Ahmed.

it seems that you are very advanced in FEA, so i would like to ask you another question if you don’t mind, because my transition from Ansys (where evrything is user defined) to simscale is little bit hard, so the question is, for an harmonic analysis can we verify the cenvergence creterium of the algorithm used and the frequency steps that the solver defines.

I hope that you understand the question.

thanks.

The convergence criteria can be set under **Numerics**. Furthermore, you can of course define the frequency steps under **Simulation Control**.

Best,

Ahmed