Study On The State Monitoring Of Aluminum Alloy Sheet Based On Lamb Wave

In recent years,with the continuous progress of smart materials and micro-electromechanical equipment technology,a variety of damage detection systems using smart materials as sensor elements have emerged.In this thesis,piezoelectric ceramics are used as sensing and exciting elements.Lamb wave is used to monitor the structural health of sheet metal in real time,and a new energy supply mode is proposed to provide guidance for the construction of self-powered structural health monitoring system.In this thesis,some technical methods of structural health monitoring of aluminum sheet are studied.The main research work includes:(1)Through the theory of elasticity,the mechanical model of Lamb wave propagation characteristics is completed,and the multimodal characteristics of Lamb wave are analyzed theoretically.The positive and negative piezoelectric effects of piezoelectric ceramics are introduced.The propagation path of Lamb wave in sheet metal is simulated.(2)A variety of signal processing algorithms(adaptive damage signal extraction algorithm,original signal filtering algorithm,sectional interception correlation coefficient algorithm and head wave energy spectrum analysis and damage region partition algorithm)and reconstruction algorithm for probability inspection of damage(RAPID)location imaging algorithm are proposed.The location accuracy of the optimized RAPID algorithm and basic algorithm is experimentally studied.The imaging effects were compared.(3)In order to transmit the data of material damage status and damage location to the data center in real time.a new energy supply method based on piezoelectric ceramics is proposed.By calculating the energy demand of the excitation system.the piezoelectric ceramics can theoretically be used to provide the supply.The basic energy harvesting circuit is simulated and experimentally analyzed.The self-powered optimized inductance synchronous switch extraction circuit is proposed.The energy extraction efficiency of the circuit and the basic circuit is improved through experimental comparison.(4)The power management module is designed to regulate the output voltage of collected electric energy,and the wireless sensor network is built.The transmission process is experimented with temperature data.The experimental results verify the feasibility of this power supply mode.