Experimental and computational evaluation of modal identification techniques for structural damping estimation

The damping ratio is a key indicator of structures susceptability to human discomfort due dynamic loads. Computational models, wind tunnel studies and empirical data can provide estimates the structure. However, only true way investigate structure through modal identification using from field tests carried out on full-scale finished This paper investigates efficacy three methods for estimating first two modes ambient data. considered are Bayesian Fast Fourier Transform (BFFT), Random Decrement Technique (RDT), hybrid RDT which decomposes into sub signals Analytical Mode Decomposition (AMD) referred as AMD-RDT. Each method applied case in order accuracy their estimates. study experimental involves excitation scaled model shake table; second considers computational tall building under simulated It was found that AMD-RDT superior estimation, particularly estimation mode, even when were closely spaced. length time series used noise within seen affect studied.