Mode Participation Factor and Effective Mass — Lesson 4

In modal analysis, how many modes do we need to investigate? There can be thousands to millions! Is every mode equally important? The answer is no. How can we know if we are looking at a significant mode, if we have missed any of them, and how many modes to extract?

Have a look as we show each of the first 100 modes of a drone in rapid sequence to give an idea of the different shapes. Which should we be interested in?

In this lesson we will answer these questions by introducing the mode participation factor and the concept of effective mass. These techniques will give us the needed insight to better understand and answer these questions.

Lecture

Alternate video link.

Note: For calculation of the Mode Participation Factor to solve a simple Spring-Mass System, the participation factor matrix has the value of 0.2379 in the second row. The respective changes are incorporated in the following handout slides.

Handout

Here are the accompanying handout slides for this lesson.