**Hey everyone,**

I’m working on a harmonic analysis simulation and have a question about splitting the frequency range.

Let’s say the frequency range I’m analyzing is from **10 Hz to 100 Hz**. Instead of running the harmonic simulation for the entire range in one go, is it feasible to split the range into smaller intervals, for example:

- One simulation for
**10-50 Hz**, and - Another for
**50-100 Hz**?

I’m trying to understand if this approach would still provide accurate results or if there are any drawbacks, particularly at the boundaries where the ranges are split. Has anyone used this method in their analysis, and if so, were there any issues with accuracy or continuity?

From my understanding, harmonic analysis calculates the steady-state response at a specific frequency. For example, consider the system at **10 Hz**, assuming no damping. We know the equation is:

M(x′′)+k(x)=Fsin(ωt)M(x’') + k(x) = F \sin(\omega t)M(x′′)+k(x)=Fsin(ωt)

Since **10 Hz** is the starting frequency, the initial displacement at all nodes would be zero, x(t)=0x(t) = 0x(t)=0. By solving this, we get the response for this frequency.

Now, when the solver moves to **11 Hz**, will it assume the initial displacement is zero again, or will it consider the solution from the previous frequency?

I’d appreciate any insights or suggestions regarding the feasibility of splitting the frequency range and how solvers handle initial conditions between different frequencies.