EastEng1012
Structural
Hello,
We are running a modal analysis on a tank structure (modeled with shell elements. We have run several modal analyzes for the model with different mesh sizes to evaluate the mesh sensitivity. The modal analysis results appear to have similar cumulative mass participation but the frequencies and mass participation of the dominant modes appear to change for each mesh size. That is the frequency for dominant modes change along with the mass participation. It appears some of the mass participation splits up into several individual modes with very similar frequencies. The mode shapes themselves appear to be similar although there are a few outliers.
My questions to experienced users:
1. Which criteria is most important for checking the mesh convergence for the modal analysis? Should we focus on the natural period (first mode) or the dominant modes frequency/mass participation?
Appreciate any input.
We are running a modal analysis on a tank structure (modeled with shell elements. We have run several modal analyzes for the model with different mesh sizes to evaluate the mesh sensitivity. The modal analysis results appear to have similar cumulative mass participation but the frequencies and mass participation of the dominant modes appear to change for each mesh size. That is the frequency for dominant modes change along with the mass participation. It appears some of the mass participation splits up into several individual modes with very similar frequencies. The mode shapes themselves appear to be similar although there are a few outliers.
My questions to experienced users:
1. Which criteria is most important for checking the mesh convergence for the modal analysis? Should we focus on the natural period (first mode) or the dominant modes frequency/mass participation?
Appreciate any input.
