COBEM99

S21 Vibrações e Análise Modal

Title:

AVALIAÇÃO EXPERIMENTAL DE UMA TÉCNICA DE IDENTIFICAÇÃO DE FORÇAS BASEADO NA DECONVOLUÇÃO NO DOMÍNIO DO TEMPO

Summary :

ABSTRACT. THIS PAPER ADDRESSES THE IDENTIFICATION OF EXCITATION FORCES FROM THE DYNAMIC RESPONSES OF VIBRATING LINEAR SYSTEMS. A METHOD IS INVESTIGATED BASED ON THE INVERSION OF THE MULTI-INPUT-MULTI-OUTPUT TRANSFER RELATION IN THE TIME DOMAIN, EXPRESSED AS A CONVOLUTION INTEGRAL HAVING THE MATRIX OF IMPULSE RESPONSE FUNCTIONS AS ITS KERNEL. THE MAIN OBJECTIVE IS TO EVALUATE THE PERFORMANCE AND ROBUSTNESS OF THE METHOD WHEN APPLIED TO A REAL-WORLD STRUCTURE, TESTED IN LABORATORY. THE PAPER IS ORGANIZED AS FOLLOWS: AFTER PRELIMINARY REMARKS CONCERNING THE METHODS WHICH HAVE BEEN USED FOR FORCE IDENTIFICATION, THE BASIC FORMULATION OF THE TIME DOMAIN-BASED DECONVOLUTION TECHNIQUE IS PRESENTED. THEN, ILL-CONDITIONING OF THE IDENTIFICATION COMPUTATIONS IS DISCUSSED AND THE CONJUGATE GRADIENT ALGORITHM, WHICH IS USED FOR OBTAINING STABLE FORCE ESTIMATES, IS PRESENTED. THE TEST-STRUCTURE AND EXPERIMENTAL PROCEDURES ARE DESCRIBED, FOLLOWED BY THE RESULTS OF VARIOUS FORCE IDENTIFICATION COMPUTATIONS, CONSIDERING DIFFERENT TYPES OF EXCITATION FORCES. BASED ON THESE RESULTS, DISCUSSION AND CONCLUSIONS ARE PRESENTED. KEY-WORDS: FORCE IDENTIFICATION, DECONVOLUTION, IMPULSE RESPONSE FUNCTION, INVERSE PROBLEMS, ILL-CONDITIONING

Author :

da Silva, Leandro Afonso
Rade, Domingos Alves

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