scholarly journals Методи діагностування дефектів деталей авіаційних двигунів з композиційних матеріалів

2021 ◽  
pp. 102-109
Author(s):  
Володимир Олександрович Пальчиковський ◽  
Андрій Володимирович Морозов ◽  
Юрій Іванович Торба

The key priority in improving the technical and economic performance of gas turbine engines lays in the use of new composite materials. The use of composites in the components of critical load-carrying structures operating under static and dynamic loads during long service lives determines the need to predict the component lives. Also, in order to increase the safety of engine operation and improve the parts manufacturing process, timely defect detection in such structures is of great importance. This article is devoted to the detection of the composite parts defects and damages that occur at different stages of manufacturing and operation. The aim is to investigate the existing methods of non-destructive testing of composite materials, describe their functional concept, and determine the field of their application. The article considers acoustic, thermal, optical, and radiation testing methods. Among the acoustic methods, the phased array method is selected as the most informative and multipurpose. The acoustic emission method is also selected; it will allow real-time monitoring of defect growth during testing. Out of thermal methods, the vibrothermography method was selected as the most advanced among the thermographic sub-methods. It allows using the phenomenon of local defect resonance and thus ensures effective defect detection. Shearography is selected for investigation out of optical methods. The special aspects of the use of X-ray methods are considered through the example of X-ray computed tomography. It is concluded that the approach combining several methods can significantly increase the efficiency of defect detecting and help to assess their criticality. Active thermal testing is well suited for fast scanning of large-sized parts and searching for areas of defect accumulation. In the following, local methods, such as impedance, vibrothermography, or one of the ultrasonic, should be used. To measure deformations under static load, it is a good practice to use shearography. To identify progressive defects under static load, it makes sense to use the acoustic emission method.

2022 ◽  
Vol 21 (4) ◽  
pp. 328-336
Author(s):  
A. V. Popov ◽  
A. O. Samuylov ◽  
I. S. Cherepanov

Introduction. The paper analyzes the application of composite materials as the main determining method of reducing the mass of the airframe and an unmanned aerial vehicle. Advanced nondestructive testing methods provide assessing the technical condition of these materials, as well as determining stress concentrators on the airframe and an unmanned aerial vehicle with high accuracy in order to make a decision on the further operation of this object under control. The objective of the work was to increase the accuracy and efficiency of the assessment of crack resistance of composite materials through the acoustic emission control.Materials and Methods. This paper presents the nomenclature of composite materials used in the construction of various aircraft, including unmanned aerial vehicles. The most possible probable defects of these materials due to the influence of operational factors are presented. The applied methods of nondestructive testing of composite material and selection of the most suitable one according to specific advantages were compared. An experiment was carried out to determine the strength limits of carbon fiber using a hardware and software complex by acoustic emission method. The research results are presented in the form of drawings projected by the hardware and software complex.Results. The application of the acoustic-emission method of composite material control is described.Discussion and Conclusions. The results obtained experimentally can be used in the process of determining the strength limits of various composite materials by the acoustic emission method of nondestructive testing to assess the technical condition in mechanical engineering, shipbuilding, and aircraft construction. The paper is recommended to researchers involved in the design of aircraft and unmanned aerial vehicles.


2012 ◽  
Vol 232 ◽  
pp. 28-32 ◽  
Author(s):  
Alexander Urbahs ◽  
Mukharbiy Banov ◽  
Vladislav Turko ◽  
Kristine Tsaryova

The work is dedicated to the experimental study of micromechanics process of unidirectional composite materials’ specimens under static loading till its fracture using acoustic emission method compared with the strain-load deformation curve. An attempt is made to identify subtle effects of the failure process of the composite material which is impossible using the traditional methods of the strain measurement. The prospect of applying the method of acoustic emission (AE) for the development and improvement of existing methods of model tense- analysis is shown. The characteristic stages of the damage accumulation for unidirectional composites’ specimens and the effect of training on these processes are shown experimentally. It’s shown that the AE-deformation diagram have three stages in contrast to commonly used load-strain deformation curve with one stage. So it become possible to investigate the physical process of composite unit’s fracture under static load.


2004 ◽  
Vol 40 (7) ◽  
pp. 455-461 ◽  
Author(s):  
L. N. Stepanova ◽  
E. Yu. Lebedev ◽  
A. E. Kareev ◽  
V. N. Chaplygin ◽  
S. A. Katarushkin

2017 ◽  
Vol 134 ◽  
pp. 28-37 ◽  
Author(s):  
Mohamad G. Droubi ◽  
Nadimul H. Faisal ◽  
Fraser Orr ◽  
John A. Steel ◽  
Mohamed El-Shaib

Aviation ◽  
2020 ◽  
Vol 24 (4) ◽  
pp. 169-176
Author(s):  
Margarita Urbaha ◽  
Konrad Stefański ◽  
Mukharbiy Banov ◽  
Vladimir Shestakov

The paper presents the results of experimental studies using the acoustic emission method of samples made of fiberglass, the design feature of which is the presence of both base fibers and weft fibers. The test data are presented in relative units and the concept of staged damage accumulation is used, which allows one to recognize subtle phenomena of the nature of the destruction of fiberglass. Tests of the samples with a transverse arrangement of fibers with respect to the applied load showed that the fracture process both in the strain parameters and in the parameters of the total acoustic emission has two stages of damage accumulation: the stage of proportional change of these parameters from stress and the stage of intensive increment of these parameters. In this case, the parameter of the total acoustic emission shows that this process of destruction begins earlier by 5–6% than the strain parameter shows. The proposed methodology and equipment allows us to identify the nature of fracture and assess the tensile strength of such a “staged” composition, and also to solve the problem of what affected the structural unity violations, which may be due to the presence of a set of cracks formed during manufacturing or under the influence of stresses and the external environment during the process of loading.


Materials ◽  
2018 ◽  
Vol 12 (1) ◽  
pp. 20
Author(s):  
Justyna Zapała-Sławeta ◽  
Grzegorz Świt

The study analyzed the possibility of using the acoustic emission method to analyse the reaction of alkali with aggregate in the presence of lithium nitrate. Lithium nitrate is a chemical admixture used to reduce adverse effects of corrosion. The tests were carried out using mortars with reactive opal aggregate, stored under the conditions defined by ASTM C227. The acoustic activity of mortars with a corrosion inhibitor was referred to linear changes and microstructure of specimens in the initial reaction stages. The study found a low acoustic activity of mortars with lithium nitrate. Analysis of characteristic parameters of acoustic emission signals, combined with the observation of changes in the microstructure, made it possible to describe the corrosion processes. As the reaction progressed, signals with different characteristics were recorded, indicating aggregate cracking at the initial stage of the reaction, followed by cracking of the cement paste. The results, which were referred to the acoustic activity of reference mortars, confirmed that the reaction of opal aggregate with alkali was mitigated in mortars with lithium nitrate, and the applied acoustic emission method enabled the detection and monitoring of ASR progress.


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