Vibrational Characteristics of Multi‐Cellular Structures

Abstract

Experimental study is carried out to verify the grillage idealization for dynamic analysis of multi‐cellular structures. Perspex material is used to construct two models of same size, one with no web openings and the other with 25% web openings. The natural frequencies and the corresponding mode shapes are determined for two different sets of boundary conditions, namely all four sides simply supported, two opposite sides simply supported, and the remaining sides free. The experimental results are found to compare well with the theoretical results using grillage idealization and finite element methods. As the linear response due to any dynamic load is the superposition of the modal components, it is concluded that the grillage idealization could be used to predict the forced vibration response of multi‐cellular structures. Since the study is restricted to linear elastic range, the findings of this investigation are applicable to structures made of other material, e.g., steel cellular structures.