Non-destructive testing derived parameters for microstructure-based residual service life assessment of aging metallic materials in nuclear engineering

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.

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Data correlation of non-destructive testing methods to assess asphalt pavement thickness

10.5194/egusphere-egu2020-3422 ◽

2020 ◽

Author(s):

Christina Plati ◽

Andreas Loizos ◽

Konstantinos Gkyrtis

Keyword(s):

Service Life ◽

Response Analysis ◽

Specific Information ◽

Non Destructive Testing ◽

Destructive Testing ◽

Processing Scheme ◽

Pavement Evaluation ◽

Pavement Response ◽

Surface Deflections ◽

Non Destructive

Performing structural assessment at any time of asphalt pavements service life is an inherent process within pavement condition assessment. Layers thicknesses are among the major contributors to the overall pavement response and performance. Knowledge of layer thicknesses is imperative for both new and in-service pavements, because thickness data is usually combined with other response indicators (i.e. pavement deflections) in order to perform pavement evaluation during pavements service life. As such, inaccuracies in thickness assessment might result in erroneous response analysis and life expectancy estimation with a detrimental financial impact during maintenance planning.Traditionally, layer thicknesses were retrieved through coring or digging test pits. Because of the limitations of these methods (including location-specific information, destructive nature, need for traffic disruptions), the pavement engineering community has consistently drawn its attention to a broadened utilization of advanced Non-Destructive Testing (NDT) systems in order to non-invasively determine the pavement cross-section. The most indicative NDT tool for that purpose is the Ground Penetrating Radar (GPR), which is systematically used for layers thickness evaluation. Within the framework of pavement evaluation processes, GPR is quite often combined with the Falling Weight Deflectometer (FWD), which provides with pavement response indications in terms of surface deflections.It is worthwhile mentioning that GPR requires high expertise in order to reliably analyze the collected data and until now, there is none uniquely recognizable and universally accepted signal processing scheme. Supplementary to experienced users and analysts, investments in time and human resources are also needed to make reliable interpretations. Such reasons may potentially discourage related stakeholders from systematic GPR use, especially in cases where there are budgets constraints for the procurement and transportation logistics of multiple expensive equipment.In light of the above, related research is pursed in respect to the investigation of the ability of FWD surface deflections indexes to provide with reliable information on the Asphalt Concrete (AC) layer thicknesses. For this purpose, Long-Term Pavement Performance (LTPP) data is analyzed including FWD and GPR data as well as sample coring. A nonlinear regression based relationship is under development that preliminarily exhibits a satisfactory performance both during model fit and model accuracy evaluation. Based on the above framework, it is suggested that the NDT analysis with deflection indexes seems promising in terms of roughly producing AC thickness, thereby balancing constraints at network level.

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Non-destructive Testing of Forged Metallic Materials by Active Infrared Thermography

International Journal of Thermophysics ◽

10.1007/s10765-012-1275-0 ◽

2012 ◽

Cited By ~ 2

Author(s):

S. Maillard ◽

J. Cadith ◽

P. Bouteille ◽

G. Legros ◽

J. L. Bodnar ◽

...

Keyword(s):

Infrared Thermography ◽

Metallic Materials ◽

Non Destructive Testing ◽

Destructive Testing ◽

Active Infrared Thermography ◽

Non Destructive

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Influence of Test Specimens Shape on Measurements of Electrical Resistivity of Concrete

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.634.479 ◽

2014 ◽

Vol 634 ◽

pp. 479-484

Author(s):

Ronaldo Alves Medeiros ◽

Maryangela Geimba Lima

Keyword(s):

Electrical Resistivity ◽

Service Life ◽

Low Cost ◽

Cylindrical Shape ◽

Non Destructive Testing ◽

Destructive Testing ◽

Use Of Data ◽

New Models ◽

Non Destructive ◽

Execution Technique

The need to insert the durability factor on dimensioning concrete structures has been stimulating the development of new models to predict the service life of those structures. Among those new models, the use of data from Non-Destructive Testing (NDT) is recommended. It is known that electrical resistivity is a parameter related with permeability and, in consequence, with the resistance of the concrete against the intrusion of aggressive agents. Electrical resistivity may be monitored with time by a NDT method, by a low cost and easy execution technique. However, some parameters of this essay need to be further discussed in the literature aiming to standardize this technique. Thus, this study had the goal to verify the influence of test specimen’s shape in measurements of electrical resistivity. In order to that, cylindrical and prismatic test specimens have been molded from a same type of concrete and electrical resistivity was monitored during a period of 120 days. Results show significant differences between the values obtained. Test specimens in cylindrical shape had the higher results. A good correlation between factors was found with R2 higher than 0.94.

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Towards optimised and reconstructable sampling inspection of pipe integrity for improved efficiency of non-destructive testing

Water Science & Technology Water Supply ◽

10.2166/ws.2017.129 ◽

2017 ◽

Vol 18 (2) ◽

pp. 515-523 ◽

Cited By ~ 1

Author(s):

Lei Shi ◽

Jaime Valls Miro

Keyword(s):

Risk Estimation ◽

Life Assessment ◽

Non Destructive Testing ◽

Destructive Testing ◽

Sampling Inspection ◽

Cost Efficiencies ◽

Residual Part ◽

Equivalent Measure ◽

Remaining Life Assessment ◽

Non Destructive

Abstract This work proposes a sampling inspection framework for point measurement non-destructive testing of pipelines to improve its time and cost efficiencies. Remaining pipe wall thickness data from limited dense inspection are modelled with spatial statistics approaches. The spatial dependence in the available data and some subjective requirements provide a reference for selecting a most efficient sampling inspection scheme. With the learned model and the selected sampling scheme, the effort of inspecting the residual part of the same pipeline or cohort will be significantly reduced from dense inspection to sampling inspection, and the full information can be reconstructed from samples while maintaining a reasonable accuracy. The recovered thickness map can be used as an equivalent measure to the dense inspection for subsequent structural analysis for failure risk estimation or remaining life assessment.

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Dimensional effect when measuring Martens hardness

Bulletin of Kharkov National Automobile and Highway University ◽

10.30977/bul.2219-5548.2021.94.0.128 ◽

2021 ◽

pp. 128

Author(s):

Vasyl Moshchenok ◽

Lyidmila Kostina ◽

Denis Pluzhnikov

Keyword(s):

Service Life ◽

Functional Dependence ◽

Test Method ◽

Structural Defects ◽

Non Destructive Testing ◽

Destructive Testing ◽

High Productivity ◽

Dimensional Effect ◽

Meyer Equation ◽

Non Destructive

One of the most common methods of non-destructive testing, hardness testing, is used to evaluate the properties of materials. This is due to the ease of measurement and testing of the finished part, which will be used in the future, high productivity of the method, the ability to assess other mechanical properties of the material: elasticity, creep, tensile strength. An important aspect in the study of the hardness using in the range the Berkovich and Vickers indenters, which are more consistent with non-destructive testing, while the methods of Brinell and Rockwell leave quite large deformations, in our opinion, which further promote the development of structural defects and reduce the service life, which are not acceptable in critical products. Due to the improvement of product manufacturability, more and more manufacturers are trying to minimize the size of the part, while increasing their performance by applying a reinforced layer, which, in turn, should seek to reduce the thickness with increased service life. It is also impossible to study the hardness of very small products in the micro range due to the large mismatch between the dimensions of the product under test and the test method. In our opinion, the study of hardness by the Berkovich method in comparison with the Vickers method is more expedient for use with the same physicochemical properties of the material because of a larger scatter of hardness values between the compared methods, although they should be almost the same, with a small difference. An important omission to a certain year was the dimensional effect. Goal. The aim of the study is to assess the nature of the change in hardness with increasing load on the indenter, using the functional dependence of the hardness on the depth of the indenter. For this purpose, it is necessary to establish such connection for an indenter of various geometry. In this regard, we consider it appropriate to check the validity of the Meyer equation, which relates the load to the size of the imprint, for different indenters and materials. Results. When the hardness is calculated according to the Martens scales, the Vickers and Berkovich indenters are applied to the function of the surface area of the working part of the tip. An important factor of the consistency of the results in the increase in hardness is the small effect. The reasons for this can be very negligible. The sizeable effect is significantly infused into the results of increasing hardness, changing from 2,5 to 3,0 folds.

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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

Kontrol Diagnostika ◽

10.14489/td.2021.03.pp.004-015 ◽

2021 ◽

pp. 4-15

Author(s):

S. O. Kozel'skaya ◽

D. A. Akimov ◽

A. S. Andreev ◽

O. N. Budadin ◽

V. V. Kotel'nikov

Keyword(s):

Composite Materials ◽

Service Life ◽

Polymer Composite ◽

Prediction Models ◽

Test Methods ◽

Operational Stability ◽

Polymer Composite Materials ◽

Non Destructive Testing ◽

Destructive Testing ◽

Non Destructive

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.

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