A novel definition for quantification of mode shape complexity

Complex mode shapes are quite often encountered in structural dynamics. However, there is no universally accepted parameter for the quantification of mode shape complexity. After reviewing the existing methods, a novel approach is proposed in this paper in order to quantify mode shape complexity for general structures. The new parameter proposed in this paper is based on conservation of energy principle when a structure is vibrating at a specific mode during a period of vibration. The levels of complexity of the individual mode shapes of a sample structure are then quantified using the proposed new parameter and the other parameters available in the literature. The corresponding results are compared, the validity and the generality of the new parameter are demonstrated for various damping scenarios.

► A detailed literature review on quantification of mode shape complexity is presented.
► A novel approach is proposed in order to quantify mode shape complexity.
► The performance of the new parameter is demonstrated for all damping scenarios.
► Results are compared with those obtained from existing approaches in the literature.
► The validity and the generality of the new parameter are demonstrated.