The Comparison On Different Experimental Modal Parameter Analysis Methods In Car-body

Though the experimental modal analysis of the car-body, we can know its dynamiccharacteristics. Estimating its modal parameters, we can have natural frequencies anddamping coefficients and vibration shapes, and make an analysis and optimization of itsstructureThis article has some analysis on three algorithms of Least Squares ComplexExponential (LSCE), Poly-reference Least Squares Complex Frequency-domain (PolyMax)and Poly-reference Maximum Likelihood Estimation (PMLE) from the perspective of theory.Then, a rectangle model is established, simulated and analyzed by three kinds of algorithms tocompare their robustness and accuracy. Next, estimate modal parameters of two kinds ofdifferent damping car-body by these three methods to compare the applicability. For smalldamping car-body, PMLE can require the most accurate parameters, then the second is LSCE,the last is PolyMax; For high damping car-body, the best is also PMLE, the second isPolyMax, the last is LSCE. For the estimation on intensive modal, the best is PMLE, thesecond is PolyMax, LSCE is the last.The contrastive research of experimental modal analysis of the car-body can fix theproblem of how to decide the proper algorithm for different damping model, and enrich thetheory of car-body modal analysis.