Damage identification in continuous beams and frame structures using the Residual Error Method in the Movement Equation

In general, the structures are submitted during their useful life to deterioration processes that, depending on the intensity, may affect their performance and load capacity and consequently their safety. In this case, it is necessary to accomplish an inspection in order to evaluate the conditions of the structure and to locate and quantify the intensity of the damage. In this study, a method to identify and to quantify damage in structures, called Residual Err or Method in the Movement Equation [Localizacao e quantificacao de danos em estruturas por meio de suas caracteristicas dinamicas. Universidade de Brasilia, Brasilia, DF, 2000] is evaluated, by a numerical analysis, to verify its efficiency when applied to continuous beams and frame structures. This method is based on the alteration, produced by damage, in the dynamic properties of the structures. The location of the damage is done observing the error in the movement equation of the intact structures. The structures are discretized in finite elements and the damage is introduced by a stiffness and area reduction of the elements' cross-sections. Other two methods of damage detection used in this paper are: the Damage Detection from Changes in Curvature Mode Shapes [J. Sound Vibration 145 (1991) 321] and the indexes MAC [Proc. 1st Int. Modal Anal. Conf. 1 (1982) 110] and COMAC [Proc. 6th Int. Modal Anal. Conf. 1 (1988) 690]. Observing the obtained results, the Residual Error Method in the Movement Equation is efficient in the damage location and quantification of the studied structures. (C) 2003 Elsevier B.V. All rights reserved.