查看文章

The present experimental work further investigate and evaluate an innovative monitoring system for various structural health monitoring applications based on an electromechanical impedance (or admittance)-type approach. The system evaluates the variations in the output voltage of piezoelectric transducers and does not compute the impedance (or admittance) itself. The proposed system is a low cost, portable, and wireless measuring system which could efficiently replace commercial instruments in concrete and steel-concrete composite bridge structures. The damage detection is achieved by simply comparing changes in root mean square voltage from response signals produced on the surface of piezoelectric transducers, such as lead zirconate titanate (PZT) patches bonded to the structure. Those changes occur when damage alters the mechanical impedance of the examined concrete structure and when propagating guided waves encounter structural damage. Experimental models of damages occurring in conventional unreinforced and steel-reinforced concrete beams are investigated. Results illustrate that the proposed integrated technique is an efficient approach for damage identification and early detection.