Development of ultrasonic transducers applied to nondestructive evaluation

• Grant number: 09/09850-1
• Support Opportunities: Regular Research Grants
• Start date: November 01, 2009
• End date: October 31, 2011
• Field of knowledge: Engineering - Electrical Engineering - Electrical, Magnetic and Electronic Measurements, Instrumentation
• Principal Investigator: Flávio Buiochi
• Grantee: Flávio Buiochi
• Host Institution: Escola Politécnica (EP). Universidade de São Paulo (USP). São Paulo , SP, Brazil

Abstract

This research project aims to design and construct conventional and array ultrasound transducers made of either piezoelectric or piezocomposite materials, with frequencies between 0.5 and 5MHz, for nondestructive evaluation. Computational methodologies will be implemented. Theses will be related to transducer modeling, simulation of acoustic wave propagation in fluid and solid media, wave interactions with interfaces and flaws, and reception by transducers operating in pulse-echo mode.New methods will be applied for the development of conventional and array ultrasound transducers for solid and water coupling (1 to 5MHz), as well as air-coupled transducers (0.5 a 2MHz). The basic requirements are: generation of a short ultrasonic pulse, and reception of acoustic signals with high sensitivity. To reach these requirements it is necessary to guarantee the acoustic impedance matching between the piezoelectric/piezocomposite ceramic and the external medium.The prototypes performance will be evaluated by comparing the theoretical model results to the experimentally measured transducers characteristics. Furthermore, the prototypes will be examined concerning its ability to detect flaws in testing objects, using ultrasound nondestructive evaluation. Experimental (ultrasonic imaging, B-scan, obtained by signal processing technique) and theoretical results will also be compared. (AU)