APPLICATION OF DEEP NEURAL NETWORKS BASED ON PALLIATIVE ANALYSIS UNDER CONDITIONS OF INCOMPLETE INFORMATION OF OPTICAL THERMAL AND ELECTRIC NONDESTRUCTIVE TESTING FOR PREDICTION OF THE LIMIT RESOURCE OF OPERATION OF CONSTRUCTION

2021 ◽  
pp. 4-15
Author(s):  
S. O. Kozel'skaya ◽  
D. A. Akimov ◽  
A. S. Andreev ◽  
O. N. Budadin ◽  
V. V. Kotel'nikov

The problem of assessing operational stability and, accordingly, assessing the storage and safe operation periods of objects (for example, load-bearing structural structures made of polymer composite materials (PCM)) has always been one of the most important. At present, this prediction problem is mainly solved on the basis of product testing, as well as a detailed study of the regularities of the physicochemical aging processes occurring in PCM and changes in the physical and mechanical characteristics of products, and the creation on this basis of appropriate test methods and mathematical prediction models. The paper considers the problem of increasing the reliability of assessing the maximum service life of multicomponent structures by constructing predictive models using the results of optical-thermal and electrical non-destructive testing of the state of objects by temperature fields and the value of internal deformation of the material under force on the structure as input information. It is shown that in the case of using logical approaches as a software tool for predicting the ultimate resource of structures made of polymer composite materials, part of the knowledge should be used for reasoning that provides an explanation of the conclusions drawn, since formal logic is of limited applicability, especially in conditions of incomplete or uncertain information. In this case, the solution to the problem becomes the identification and establishment of cause-and-effect relationships. For the tasks of technical assessment of the quality of structures and their service life, the use of such logical conclusions as inductive, deductive and analogous conclusions is impossible, since for their work, they require all information about the diagnosed structure. The use of the proposed method for assessing the service life will allow timely stopping the loading of products with loads and, thus, preventing structural destruction. It should be borne in mind that in order to reliably predict the ultimate service life of complex structures made of composite materials using the proposed method, a set of various input instrumental and subjective information about the structural and operational characteristics of the product is required, including information on intermediate tests, non-destructive testing data. at various stages of manufacturing, design features, stability of parameters during the development process, subjective opinions of specialists, changes in the properties of materials from time to time and loads, etc. Implementation of the proposed approach will allow creating a new generation of test methods and predicting operational stability with an assessment of the limiting service life of elements and structures, which, ultimately, will provide an additional opportunity for developing practical recommendations for confirming or extending the warranty periods of operation and increasing the reliability and safety of operation of structures.

2021 ◽  
Vol 3 (134) ◽  
pp. 135-148
Author(s):  
Svitlana Klymenko ◽  
Pavlo Kiselyov ◽  
Oleksii Kulyk

The development of modern rocket and space technology (RST) is characterized by constant improvement: increasing speed, range and altitude. Improving these characteristics, through modernization, has led to a significant complication of the design of RST and its equipment. Among the most promising materials for the manufacture of RST structures are more often used polymer composite materials (PCM), which are increasingly used in modern RST engineering, especially in cases where no other material meets the new requirements. Quality control of RST products depends on determining the condition of materials in these facilities, both in production and in operating conditions, which must be carried out both in the production process (with the deviation of production processes may form different types of structure heterogeneity: porosity, foreign inclusions, stratification and cracks) and during operation. In polymer composite materials RST, namely to detect defects such as delamination and cracks using ultrasonic non-destructive testing. An analysis of the use of traditional ultrasonic non-destructive testing using a portable ultrasonic flaw detector using high-frequency transducers. It has been determined that it is sufficient to use portable ultrasonic flaw detectors to detect longitudinal cracks or stratifications, but for more reliable detection and detection of defects, completeness of control should use automated ultrasonic control systems that have greater sensitivity and scanning speed. defective zones with the possibility of constructing a qualitative image of the defective zone for further assessment of the performance of the entire structure with PCM.


Author(s):  
S.O. Kozelskaya ◽  

The problem is considered related to increase of the operational safety of industrial facilities made of composite materials by means of an a priori assessment of the maximum service life. Two tasks are being solved: development of the new methods and means of non-destructive testing allowing to identify the defects that appear in the process of testing products with various loads and in the process of their operation; development of the new methods and means for assessing service life of the products based on the results of non-destructive testing. The first problem is being solved by the development of optical-thermographic non-destructive testing, including the technologies of ultrasonic thermotomography and electric force thermography, which determine the state of the object by dynamic temperature fields and optical control technology based on the fiber-optic sensors that measure the amount of material internal deformation under a force effect on the structure. Solution to the second problem is based on the use of neural network analysis (artificial neural networks) for assessment and prediction of the service life using the results of non-destructive testing with preliminary training of the neural network. An estimate was obtained by the experimental studies related to the error in determining the products service life, which is 12.6 %. The implementation of the proposed approach will allow to create the new technologies for predicting the service life of elements and structures made of composite materials using the results of non-destructive testing, which will provide an additional opportunity for developing practical recommendations on the confirmation or extension of the service life and improvement of safety for structures operation.


2020 ◽  
Vol 12 (4) ◽  
pp. 168781402091376 ◽  
Author(s):  
Bing Wang ◽  
Shuncong Zhong ◽  
Tung-Lik Lee ◽  
Kevin S Fancey ◽  
Jiawei Mi

Composite materials/structures are advancing in product efficiency, cost-effectiveness and the development of superior specific properties. There are increasing demands in their applications to load-carrying structures in aerospace, wind turbines, transportation, medical equipment and so on. Thus, robust and reliable non-destructive testing of composites is essential to reduce safety concerns and maintenance costs. There have been various non-destructive testing methods built upon different principles for quality assurance during the whole lifecycle of a composite product. This article reviews the most established non-destructive testing techniques for detection and evaluation of defects/damage evolution in composites. These include acoustic emission, ultrasonic testing, infrared thermography, terahertz testing, shearography, digital image correlation, as well as X-ray and neutron imaging. For each non-destructive testing technique, we cover a brief historical background, principles, standard practices, equipment and facilities used for composite research. We also compare and discuss their benefits and limitations and further summarise their capabilities and applications to composite structures. Each non-destructive testing technique has its own potential and rarely achieves a full-scale diagnosis of structural integrity. Future development of non-destructive testing techniques for composites will be directed towards intelligent and automated inspection systems with high accuracy and efficient data processing capabilities.


2019 ◽  
Vol 9 (14) ◽  
pp. 2810 ◽  
Author(s):  
Azadeh Noori Hoshyar ◽  
Maria Rashidi ◽  
Ranjith Liyanapathirana ◽  
Bijan Samali

Monitoring of structures to identify types of damages that occur under loading is essential in practical applications of civil infrastructure. In this paper, we detect and visualize damage based on several non-destructive testing (NDT) methods. A machine learning (ML) approach based on the Support Vector Machine (SVM) method is developed to prevent misdirection of the event interpretation of what is happening in the material. The objective is to identify cracks in the early stages, to reduce the risk of failure in structures. Theoretical and experimental analyses are derived by computing the performance indicators on the smart aggregate (SA)-based sensor data for concrete and reinforced-concrete (RC) beams. Validity assessment of the proposed indices was addressed through a comparative analysis with traditional SVM. The developed ML algorithms are shown to recognize cracks with a higher accuracy than the traditional SVM. Additionally, we propose different algorithms for microwave- or millimeter-wave imaging of steel plates, composite materials, and metal plates, to identify and visualize cracks. The proposed algorithm for steel plates is based on the gradient magnitude in four directions of an image, and is followed by the edge detection technique. Three algorithms were proposed for each of composite materials and metal plates, and are based on 2D fast Fourier transform (FFT) and hybrid fuzzy c-mean techniques, respectively. The proposed algorithms were able to recognize and visualize the cracking incurred in the structure more efficiently than the traditional techniques. The reported results are expected to be beneficial for NDT-based applications, particularly in civil engineering.


2020 ◽  
Vol 39 (3) ◽  
Author(s):  
Jagoda Nowak-Grzebyta ◽  
Frans Meijer ◽  
Karol Bula ◽  
Ewa Stachowska

Abstract This paper presents the use of a digital holographic vibrometer to investigate metal-polymer laminates by non-destructive testing. A polymer strip was glued to a metal one of the same size. Connection defects could be detected by a local change of the vibration amplitude, even when hidden from view for the observer. The amplitudes of the oscillations excited in the samples were up to 40 nm. This method proved to be non-destructive, allowing the samples to be (re)used after testing, or being studied with other test methods.


Sign in / Sign up

Export Citation Format

Share Document