Follow Along: Modal Analysis

This lesson will give an overview of how to run a modal analysis in nTop. For this lesson, we’ll use the completed file from the optional simulation test problem in our last lesson. If you completed that lesson, you can continue in your current file, or you can download the nTop file below to get started.

In addition to the static analysis we ran previously, we can also run a modal analysis in nTop. I’ll come up here to our analysis section and choose the Modal Analysis block to drop into our notebook. I’ll create a new section called “Modal Analysis,” and I can pull our block into the workflow. This block can also be found under “Design Analysis” in our analysis section.

For our model, we can use the same FE model we created earlier. The only boundary conditions we need here are the displacement restraints at these upper two holes. For now, I’ll input two for our number of modes, and we can run that analysis.

I’ll isolate using “I” to view our results. If we come over here to our heads-up display, we can toggle among different frequencies depending on the number of modes we’ve input. So if I input four modes, we’ve got our four resulting eigenvalues to view. We can view our results in terms of the total model or displacement in either the X, Y, or Z direction. We can also adjust our deformation scale slider to better visualize our results. We can also modify the upper and lower ends of our deformation gradient.

Coming back to our Modal Analysis block, we have the option to add a minimum and maximum values for our returned frequencies. Finally, if we open up our block details under “Properties,” we have scalar values of our eigenfrequencies that we’ve generated from our analysis, and we have displacement fields for each of our modes, which can be used later for field-driven design. And that is an overview of our modal analysis in nTop.