Identification of Structural Defects of Metal Composite Castings with The Use of Elastic Waves

Abstract

The method of elastic wave propagation was applied to detect defects in composite castings (ingots). If a defect occurs, which is detected by the radiography, elastic wave propagation changes locally, i.e. causes disturbance of elastic wave propagation. Methods of signal analysis based on wavelet decomposition were used. Calculations related with wavelet analysis were made in the MATLAB environment using standard Wavelet Toolbox functions.Keywords: acoustic emission, wavelet transform, quality of composite castings Wykorzystano metodę badań bazującą na propagacji fal sprężystych do wykrywania wad odlewów kompozytowych. Poddano obserwacji lokalne zmiany propagacji fali sprężystej podczas analizowania defektów, których występowanie potwierdzono za pomocą defektoskopii radiologicznej. Zastosowano metody analizy sygnałów oparte na dekompozycji falkowej. Obliczenie transformat falkowych wykonano w środowisku MATLAB z wykorzystaniem standardowych funkcji Wavelet Toolbox.

The Use of Acoustic Emission Elastic Waves for Diagnosing High Pressure Mud Pumps Used on Drilling Rigs

“…The acoustic emission signal makes it possible to use non-linear methods of signal analysis in diagnostic inference. The following material characteristics are associated with these methods [12,14,15,18,19]: local deformation hysteresis and discrete 'memory' of the material, downward shift of the frequency resonance band, in proportion to the resonance amplitude, contrary to the classical case, where the shift is proportional to the squared amplitude, square dependence of the third harmonic amplitude, whereas using the classical theory of non-linearity this dependence should be raised to the third power, the level of attenuation depends on the amplitude, the phenomenon of 'slow dynamics', i.e., slow recovery of linear properties after the material was subjected to the impact leading to non-linearity. important.…”

“…The acoustic emission signal makes it possible to use non-linear methods of signal analysis in diagnostic inference. The following material characteristics are associated with these methods [12,14,15,18,19]:…”

“…The source of the recorded signal is the energy generated by the heterogeneity of the These effects are associated with large non-linearity, characterizing mainly gases and highly plastic materials (elastomers). In solid substances with crystalline structure, such as metals, the phenomenon of high non-linearity is often associated with degradation, the occurrence of cracks, creep, and other above-molecular defects typical of mezzo-scale damage [11,[14][15][16]18,19]. In such cases, local elasticity is different for stretching and compression, and related non-linear effects lead to increased high frequencies of the harmonics.…”

“…In the AE source the function of amplitude changes in the stress field has a form of a unit/single peak, the sensor is placed in the pump body (housing of the valve unit, and the elastic wave propagates in a homogeneous medium. The basic equation describing the signal propagation path can have this form [11][12][13][14][15][16][17][18][19]:…”

Applying the Anticipatory Failure Determination at a Very Early Stage of a System’S Development: Overview and Case Study

“…The analysis presented is part of a larger project, and the system under evaluation is the result of the application of ARIZ for finding methods of reducing fuel consumption in ships. Searching for potential failure can be supported by means of specialised software such as the aforementioned Ideation Failure Analysis TM and Ideation Failure Prediction TM (Kaplan et al, 1999), as well as on the basis of different physical chemical, biological, geometrical, and even psychological effects (AULIVE, 2017;Bejger and Gawdzińska, 2011;Boratyńska-Sala, 2016;Oxford Creativity 2017;Pajor et al, 1999;Zaplata and Pajor, 2016;Zolkiewski 2013). The ranking of the identified failures can also be made using various methods, including in addition to the aforementioned assessment matrix, a weighted average as well as methods based on direct comparisons of failure-related values of individual assessments, and the importance of individual evaluation criteria.…”