hello, I'm student who study about modal analysis, I tried modal analysis to simple 1 floored model that have 4 legs. Total mass is almost 2kg. As a result of the analysis, the effective mass in the direction of rotation far exceeds the total mass close to 60 kg. This is an abnormal result and is thought to be a mistake in the analysis setting process. However, the structure is very simple and no warning message was received during the mode analysis process. So I want to know the advice or cause of this.
The principle would be that the sum of modal effective masses would equate the actual total mass of the system (so, if you truncate the high frequency modes, slightly less).
Your results indicate an error in the normalization of your model. Please find attached a simple example where you can see how L must be normalized to ensure the correct estimation of effective masses
The principle would be that the sum of modal effective masses would equate the actual total mass of the system (so, if you truncate the high frequency modes, slightly less).
Your results indicate an error in the normalization of your model. Please find attached a simple example where you can see how L must be normalized to ensure the correct estimation of effective masses
actually, in the attached paper, the normalization is firstly applied to the eigenvectors and imposed to the ^m matrix, see top of p.5
Mass participation in all the directions should add up to total mass which is used as a check. Check your input check and fix it. Some mode wherein the participation is meaningful is ignored. May be this is the issue
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