پايش پيوسته سلامت ساختاري قطعات مكانيكي ثابت و متحرك به روش امپدانس الكترومكانيكي با استفاده از پوشش دهي فيلم ضخيم ترانسديوسر پيزوالكتريك

چكيده انگليسي :

2 Continuous Health Monitoring of Stationary and Moving Structures Based on Electromechanical Impedance Method Using Deposition of Piezoelectric Thick Film Transducer Hamidreza Hoshyarmanesh E mail hrh1983@me iut ac ir Date of Submission Dec 3 2014 Degree Ph D Language Persian Farsi Department of Mechanical Engineering Isfahan University of Technology Isfahan 84156 83111 Iran Supervisors Dr Naser Nehzat nnehzat@cc iut ac ir Dr Mehdi Salehi issst@cc iut ac ir Adviser Dr Mojtaba Ghodsi ghodsi@squ edu om Department Graduate Program Coordinator Dr M R Salimpour Mechanical Engineering Department Isfahan University of Technology Isfahan Iran Materials Engineering Department Isfahan University of Technology Isfahan Iran Department of Mechanical and Industrial Engineering Sultan Qaboos University Muscat Oman ABSTRACT ontinuous structural health monitoring of stationary and moving metallic non metallic and super alloy host structures has been considered based on electromechanical impedance admittance EMI EMA spectrum of deposited piezoelectric thick films as wafer active transducers This method is one of the practical and effective approaches to predict the probable damages improve safety reduce maintenance costs and estimate the lifetime of industrial parts in a variety of sensitive structures like turbofans compressors reactors power generation turbines space shuttles aircraft fuselage and specifically titanium or super alloy blades in aerospace industries Thin and thick piezoelectric films of a lead zirconate titanate PbZr0 52Ti0 48O3 PZT with morphotropic phase boundary MPB and perovskite structure b bismuth titanate Bi4Ti3O12 BiT c PZT PZT composite and d PZT BiT composite were deposited on flat and curved surface of silica SiO2 silicon wafer Si and platinum Pt substrates with different thicknesses and properties using photochemical metal organic deposition and hybrid sol gel techniques Thereby a desirable crack free coating was obtained with minimal agglomeration porosity residual stress and maximum achievable piezoelectric charge coefficients ferroelectric remnant polarization and dielectric constants Implementation of new eco friendly and additive free precursors to synthesize up to 100 m thick films on curved surfaces is one of the important substantial achievements in present research In this study thick piezoelectric films was also deposited on the convex surfaces of nickel based super alloy blades Ruston TA 1750 IN738 and Pratt Whitney JT8D IN718 for structural health monitoring considering negligible disturbance in dynamic behaviour and balance of rotary blades Structural mechanical morphological optical dielectric ferroelectric and piezoelectric properties along with residual stress and electromechanical response of piezoelectric thin and thick specimens were measured regarding the film thickness dimension location substrate material and thermal treatment conditions at a stationary state The characterization procedures were carried out as non destructive tests such that the piezoelectric films to be observed and checked under a defined review progress prior to commencing health monitoring of host structures The process was continued to reach a desirable film As an instance the longitudinal and transverse piezoelectric charge coefficients of thick films on the top surface of super alloy blades was measured in the range of d33 76 148 pm V and d31 28 43 pm V Thereby the response accuracy of piezoelectric films was investigated and verified in comparison with reported results of other 2

هوشيارمنش، حميدرضا

پايش پيوسته سلامت ساختاري قطعات مكانيكي ثابت و متحرك به روش امپدانس الكترومكانيكي با استفاده از پوشش دهي فيلم ضخيم ترانسديوسر پيزوالكتريك