Abstract In ultrasonic testing of coarse-grained materials, signal to noise ratio (SNR) of testing signals is reduced seriously for the structure noise, and echoes from defects are difficult to be identified. In order to improve the SNR and the reliability of ultrasonic testing of coarse-grained materials, empirical mode decomposition (EMD) is introduced to process the testing signal here. Sign...

The optimization problem of ultrasonic testing instrument is studied in this paper. Using ultrasonic nondestructive testing technology to detect quality of products or parts, because the function of conventional ultrasonic testing instruments is custom-built and defined by manufacturers, it is very difficult to meet ever-changing testing requirements such as testing accuracy, testing efficiency...

Highly sensitive air-coupled ultrasonic sensors are essential for various applications such as testing of composite materials. One of the major challenges for the development of air-coupled ultrasonic sensors is the impedance matching to air. With a lower acoustic impedance than the usual piezoelectric materials, charged cellular polypropylene film (cPP) offers better matching to air with a sim...

al’s properties and acoustical characteristics have been studied for a long time and ultrasonic techniques have been used in non-destructive testing and imaging for decades. Ultrasound as an analytical tool has revolutionised diagnostics in medicine, but the application of ultrasound to material’s analyses has been held back by problems with ultrasonic design, electronics, sample handling, comp...

This paper describes the proposal of dual filtering algorithm used for ultrasonic A-scan signal de-noising. In ultrasonic non-destructive testing the signals characterizing the material structure are evaluated. The sensitivity and resolution of typical ultrasonic systems is commonly limited by backscattering and electronic noise level commonly contained in acquired ultrasonic signals. In ultras...

This letter discusses the role electrical anisotropy plays in the structural integrity assessment of polycrystalline titanium alloys from the standpoint of fatigue crack detection and the related issue of microstructural noise. In eddy current inspection of noncubic crystallographic classes of polycrystalline metals the electric anisotropy of individual grains produces an inherent microstructur...

The paper aims to present the experimental data retrieved after ultrasonic non-destructive testing on metallic particle reinforced polymeric composite materials. The particles’ size (μm), volume fraction as well as the matrix material (different types of polymeric materials – e.g. epoxy, vinyl epoxy, etc.) has their influence on the overall elastic characteristics of the composite material. On ...

Launch vehicles use ablative nozzle liners to function under very high thermal and erosive environments. In solid motor nozzle throats, graphite or carbon phenolic materials are used because of their high heat of ablation and erosion resistance. Ultrasonic testing is implemented as the primary NDT technique for throat insert liners by almost replacing radiography testing. Though introduced for ...