S21  Vibrações e Análise Modal    Titulo: TIME DOMAIN-BASED IDENTIFICATION OF MODAL PARAMETERS AND EXCITATION FORCES USING ORTHOGONAL FUNCTIONS   Resumo : A SET OF ORTHOGONAL FUNCTIONS CAN BE INTEGRATED USING A SO-CALLED OPERATIONAL MATRIX. THIS PROPERTY CAN BE USED TO TRANSFORM LINEAR DIFFERENTIAL EQUATIONS INTO ALGEBRAIC EQUATIONS, WHICH CAN BE EASILY SOLVED. WHEN DEALING WITH MECHANICAL SYSTEMS, STRUCTURAL AND/OR MODAL MODELS CAN BE DETERMINED FROM THESE ALGEBRAIC EQUATIONS. IN THIS PAPER, THIS PROCEDURE IS INVESTIGATED BY USING DIFFERENT TYPES OF ORTHOGONAL FUNCTIONS: FOURIER SERIES, LEGENDRE POLYNOMIALS, JACOBI POLYNOMIALS, CHEBYSHEV SERIES, BLOCK-PULSE FUNCTIONS AND WALSH FUNCTIONS. A FEASIBILITY STUDY IS PERFORMED ON THIS TECHNIQUE WHEN APPLIED TO THE PROBLEMS OF MODAL PARAMETER IDENTIFICATION AND INPUT FORCE RECONSTRUCTION, USING THE TIME RESPONSES OF THE STRUCTURE. THE MAIN FEATURES AND CAPABILITIES OF THE METHOD ARE DEMONSTRATED THROUGH APPLICATIONS TO BOTH NUMERICALLY SIMULATED AND EXPERIMENTALLY TESTED MECHANICAL SYSTEMS.    Autores : PACHECO, RICARDO PEREIRA Rade, Domingos A STEFFEN, Jr, VALDER 0     Trabalho Completo :   COBEM99 | Comissão  Organizadora | Palestras | Sessões Técnicas | Autor | Simpósios e Sessões Especiais | Revisores |  Título  dos  Trabalhos | Local