Model test and numerical simulation for the Structural Health Monitoring of a truss bridge.

摘要

Structural Health Monitoring (SHM) is one of the vital tools used by civil engineers to improve and monitor the health of civil infrastructure. It involves the acquisition, validation and analysis of technical data to facilitate lifecycle decision in the maintenance of structures. Data collected by SHM are converted by damage detection algorithms into useful information that helps in accessing structural integrity and performance.;This study investigates how data obtained from physical experiment and numerical simulation of a laboratory truss bridge model can be used for SHM.;In the numerical simulation work, three 3-D truss bridge models are created using the finite element method. The numerical truss bridge models are based on the geometry and material properties of a scaled truss bridge model used in the physical experiment.;Artificial damage is introduced to the structure by reducing the cross-sectional area of a truss member at a 20% interval. The natural frequencies and displacement of intact and damaged truss bridge models are recorded and analyzed.;The physical experimental set-up consists of a bridge truss set, six force sensors (load cells), a load cell amplifier, a data acquisition system, and a personal computer. It produces real-time static and dynamic responses of the truss bridge model which has a span length of 42", a width of 5", and a height of 12". Three loading cases are considered, including (1) unloaded intact, (2) loaded intact, and (3) loaded damaged truss bridges. A damaged truss bridge model is created artificially by the removal of one diagonal truss member. Fast fourier transform is used for frequency analysis.