Performing Harmonic Analysis with Full Method - Lesson 5

Mode-Superposition Method is recommended for most dynamic problems due to its speed and ability to cluster results. However, there are specific cases where it cannot be used, such as systems with moderate or significant damping or systems with unsymmetrical matrices – for example, those arising from vibroacoustic or bearing problems. Hence, in such cases, Harmonic Analysis is performed with the Full Method which solves the system matrices directly without relying on mode shapes from modal analysis. This video lesson will discuss cases where it is recommended to use the Full Method for performing a Harmonic Analysis. We have a short lecture followed by a workshop walkthrough example showing how to implement the points discussed.

Alternate video link.

Video Highlights

0:25 - Specific Cases where Mode Superposition Method cannot be used

3:08 - Example demonstrating how Mode Shapes can change and become complex

7:30 - How to include Viscoelastic Damping in Harmonic analysis?

9:23 - How to use Remote Boundary Conditions for representing External Parts?

11:17 - How to set Frequency Range in Harmonic Analysis?

11:43 - Plotting and Analyzing Frequency Response Results?

12:27 - How to create Contour Plots from Frequency Response Results?

12:52 - Understanding the difference in the sign of Phase Angle in Frequency Response Chart and Contour Plot

Simulation Files

Download the accompanying geometry and archived files here. The student version of Ansys simulation software can be downloaded here.