Dynamic response and vibration signature assessment of SDOF steel system using RISAM shaking table

Abstract

Civil engineering structures face major challenges, particularly earthquakes, which are random phenomena in their intensity and frequency content. The seismic response of structures depends largely on the intensity of an earthquake and especially on its frequency content. Structural Health Monitoring (SHM) is a relevant tool for assessing the dynamic behavior of structures subjected to seismic excitations. This is achieved by using experimental measurements of structural dynamic parameters. The main objective of this study is to identify the vibration signature of a single-degree-of-freedom SDOF steel system. Based on the laws of similarity, a 1:6 reduced-scale model is developed. In this context, dynamic experiments using the shaking table of the RISAM laboratory (Risk Assessment and Management: University of Tlemcen) are carried out to determine the structural dynamic parameters of this steel system. This is achieved through experimental determination of natural frequency and damping of the reduced model. Acceleration and displacement measurements are also established. The experimental estimation of damping is established using the logarithmic decrement method. Several dynamic analyses are carried out based on the finite elements model of the reduced steel system model. The obtained results show that the approach used to determine the dynamic parameters of this reduced model leads to realistic results. On the other hand, a perfect concordance between the numerical and experimental results has been approved.