Piezoelectric Sensing Method For Loading Conditions And Deformation Of Steel Beams

To make sure the safety,durability and reliability of structures in-service,structural health monitoring(SHM)systems have been widely used in civil infrastructures in recent years.With the advantages of self-powering,fast response,high sensitivity and high signal-to-noise ratio,piezoelectric materials are one of the most widely studied and applied smart materials in the field of SHM.In this paper,we propose a method to utilize piezoelectric ceramic(PZT)sensor array to sensor the loading conditions and deformation of steel beams.Firstly,a theoretical model is established via piezoelectric theory and electromechanical analyses,which calculates the loading conditions and deformation of the steel beam from the voltage signals of PZT sensor array.After that,a series of loading conditions experiments are designed to validate the theoretical model.In the experiment,a PZT sensor array and several force sensors are arranged on the steel beam,and a mass block is used to simulate various loading conditions.The proposed method is proved effective to sensor single or multiple concentrated loads and moving load by comparing the inversion results with the measured values of the force sensor and the actual loading conditions.Experimental observations also reveal that PZT sensor array response faster to loading process than commercial force sensor,which makes it qualified in the sensing of transient loading such as impact effect in loading history.Finally,the theoretical model is used to sensor structural deformation.A PZT sensor array and a deflection meter are arranged on the steel beam,and a vibration exciter is used to load the beam with a triangular wave.The inversion results are in good agreement with the measured values of deflection meter,and the higher the loading frequency is,the higher the coincidence between the two is,demonstrating the sensitivity of PZT sensor array to dynamic load.The current method may provide a useful tool for sensing load conditions and deformation of various beam structures.