Dynamic Response and Vibration Signature of Single Degree of Freedom Steel System

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. The assessment of the dynamic behavior of structures subjected to seismic excitations is therefore essential for understanding their performance. The main objective of this study is the experimental identification of the vibration signature of a single-degree-of-freedom SDOF steel system.

Based on the laws of similarity, a 1:6 reduced-scale steel 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. 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 element model of the reduced-scale steel system.

The experimental investigations allowed the identification of the natural frequency, damping ratio, acceleration, and displacement response of the reduced-scale SDOF steel model. In addition, the numerical analyses showed a close agreement with the experimental measurements.

The comparison between numerical and experimental investigations confirms the effectiveness of the adopted methodology in accurately reproducing the dynamic behavior of the steel system. The proposed experimental and numerical framework can therefore be considered a reliable approach for evaluating the seismic response of steel structures.

This study successfully identified the vibration signature and dynamic characteristics of an SDOF steel system through combined experimental and numerical analyses. The excellent correlation between the finite element results and shaking table experiments validates the proposed methodology and highlights its applicability for future seismic assessment studies of steel structures.