Análise modal utilizando câmeras fotográficas como sensores de frequência sem contato

Abstract

This work presents a methodology to obtain the dynamic displacement signals through the processing and correlation of three-dimensional digital images, through two webcams connected to a computer. The computational interface proposed by the methodology allows the conversion of the acquired image, from the analog to the digital domain and later the location of the position of objects subjected to dynamic displacements. In the present work, It was performed experimental identification of modal parameters of a structure of the frame type. The procedure using cameras is divided into stages of pre-processing, calibration and acquisition of video, and post-processing, calculating the position of the object through the correlation of images. The data obtained through the classical methodologies, using accelerometers and instrumented hammer, and the present proposal, were used to carry out the modal analysis of the structure, with the purpose of evaluating the use of cameras as a viable alternative in the identification of the structural parameters, and presented the 1.30% difference in results.