Estimación de parámetros modales de estructuras sometidas a excitaciones ambientales

• Autor(a) principal: Amani, Marta Graciela
• Data de Publicação: 2004
• Outros Autores: Riera, Jorge Daniel, Curadelli, Raúl Oscar
• Tipo de documento: Artigo
• Idioma: spa
• Título da fonte: Repositório Institucional da UFRGS
• Texto Completo: http://hdl.handle.net/10183/214776
• topic: Estruturas (Engenharia); Dano estrutural; Dinâmica de estruturas; System identification; Modal analysis; Modal parameters

Structural monitoring under ambient vibrations has been a subject of growing interestin recent years, due to the impressive progress experienced by transducers and recordingequipment. The final objective of monitoring is to evaluate the state of the structure,without interrupting its normal operation, from vibration measurements. In general,in civil engineering structures such as bridges, tall buildings, dams or off-shore structures,the excitation will most likely be natural excitation from wind, traffic or seismic soilmotions. In those cases, so-called stochastic system identification methods are commonlyused to estimate the modal parameters. One such output only method to identify thedynamic characteristics of structures characterized by arbitrary damping and subjectedto ambient excitation is described in this paper. This approach allows obtaining the na-tural frequencies and damping from the spectral power densities of the modalaccelerations. The method is illustrated by three examples (a) a theoretical plane frameof a building, (b) a 1:50 scale aluminium storey building model tested on a vibration tableand (c) a simply supported reinforced concrete beam also tested under laboratoryconditions. The results were considered satisfactory in all cases, suggesting the it hasconsiderable potential in damage identification.