Identification of the Dominant Vibration Modes of Single-Layer Reticulated Shells under Wind Action

Abstract

In the analysis of wind-induced response of single-layer reticulated shell structures, it is found that there are some higher modes which maybe contribute significantly to the vibration. Unfortunately, these higher modes are often ignored when the traditional mode superposition methods are adopted for wind-induced response analyzing, due to the consideration of calculation efficiency. Although some more efficient methods have been put forward, they seem too complex to engineers. From the viewpoint of practice, it is expected to find these contribution-significant modes directly by some easy-understanding criterions. To solve this problem, a Ritz-POD method is introduced firstly, which synthesizes the proper orthogonal decomposition (POD) technique and the Ritz-vector direct superposition method. Based on the Ritz-POD method, some preliminary criterions for identifying the contribution-significant modes are proposed, which take account of the vibration-participating ability of each mode and the relationship between the mode shape and the spatial distribution of the fluctuating wind load.