Abstract:

The damping is an important design consideration for vibrating structures. In this paper, damping ratio in layered & bolted sandwich structure is determined by conducting sweep sine test and half power bandwidth method to Frequency Response Function (FRF). Simple beam [1] is taken as reference point and the methodology is extended for determining the damping ratio in layered and bolted sandwich structure. These structures are excited using an Electro-Dynamic Shaker excitation technique for their fundamental mode. The effect of three major parameters on structural damping is investigated by using Design of Experiment analysis. Analysis of Variance and Signal to Noise ratios analysis is also performed. The results have shown that the number of layers in sandwich construction significantly affects the damping ratio and validated using regression equations. The design concept evolved from this paper using layered structures with bolted joints can be efficiently employed in applications where higher damping is required.