EVALUATION OF DYNAMIC RESPONSE OF STEEL FRAME MOUNTED ON A SHAKE TABLE USING DIGITAL IMAGE CORRELATION TECHNIQUE

Abstract

Accurate assessment of structural dynamic response under seismic excitation is critical for the continuous evaluation and resilient design of infrastructure. This study presents a comprehensive experimental investigation into the dynamic behavior of a scaled three storey steel frame model subjected to horizontal shake table testing across varying excita tion frequencies. To capture the structural response, a dual-measurement approach was employed, contrasting traditional contact-based sensing with advanced optical techniques. Accelerometers were installed at each floor level to record structural acceleration data, which was subsequently processed using vibration analysis and Fast Fourier Transform (FFT) algorithms to derive peak frequency responses and dynamic displacements. Con currently, Digital Image Correlation (DIC), a high-resolution non-contact measurement method, was utilized to evaluate the spatial deformation characteristics of the frame. By tracking full-field surface displacements during excitation, the DIC method successfully extracted the structural mode shapes and inter-storey drift ratios without adding local ized mass or altering the frame’s inherent dynamic properties. The comparative analysis evaluates the precision, practical implementation, and data-richness of DIC against con ventional accelerometer-derived metrics. Ultimately, this research highlights the efficacy of non-contact optical sensing methodologies in advancing structural health monitoring and provides a robust framework for capturing highly detailed kinematic data in structural assessments.