Transient Response and Damping Ratio Identification of Multi-Span Bridge Plates

This study investigates transient wave propagation behavior and introduces an innovative approach for damping ratio identification in multi-span bridge plates. The transient response, incorporating damping effects, is efficiently predicted using the modal superposition method. By integrating theoretical analysis with experimental data, a refined iterative method is introduced to identify the damping ratio for each resonant frequency by extracting frequency spectrum peaks from experimental data. This simple yet effective methodology enhances the accuracy of transient response predictions. Experimental measurements of transient strain and impact force histories are obtained using polyvinylidene fluoride (PVDF) sensors. Results validate that transient strain and displacement predictions remain consistent across both time and frequency domains, especially considering damping effects. In addition, variations in identified damping ratios across different impact and sensor configurations reflect the energy dissipation when impact waves traverse simply supported boundaries, highlighting the need to combine modal damping estimates from multiple testing configurations. Compared to numerical simulations, the proposed method achieves high accuracy while significantly reducing computational effort. With its flexibility and precision, the proposed approach has the potential to be extended to complex structural systems and diverse material applications, enhancing real-time structural health monitoring across various engineering fields.