Operational control of the strength of safety parts limiting ultimate loads

2021 ◽  
pp. 45-47
Author(s):  
Keyword(s):  
Shear Strength ◽  
Test Material ◽  
Operational Control ◽  
Elastoplastic Contact ◽  
Plastic Hardness ◽  
Non Destructive

A non-destructive method for determining the shear strength of parts based on the laws of elastoplastic penetration of an indenter into a test material is considered. Experiments confirmed the effectiveness of the method in practice. Keywords: non-destructive method, shear strength, elastoplastic contact, plastic hardness. [email protected]

Study of the residual imperfections using methods of probability theory

2021 ◽  
Vol 87 (9) ◽  
pp. 44-49
Author(s):  
D. A. Kuzmin
Keyword(s):  
Probability Theory ◽  
Generalized Equation ◽  
Structural Elements ◽  
Non Destructive Testing ◽  
Operational Control ◽  
Destructive Testing ◽  
Control Procedures ◽  
Non Destructive ◽  
A Current

Discontinuities in the products that occur during manufacture, mounting or upon operation can be missed during non-destructive testing which do not provide their complete detectability at a current level of the technology. Therefore, it is necessary to take into account that certain structural elements may have discontinuities of significant dimensions. We present the results of using the methods of probability theory in studying the residual imperfections that remains in the structure after non-destructive control and repair of the previously identified defects. We used the results of operational control of units carried out by ultrasonic and radiographic methods. We present a method for determining a multifactorial coefficient that takes into account the detectability of defects, the number of control procedures and the errors in the instrumentation and methodological support, as well as a generalized equation for the probability distribution of detecting discontinuities. The developed approach provides assessing of the level of damage to the studied objects, their classification proceeding from the quantitative data and determination of the values of postulated discontinuities for deterministic calculations. The results obtained can be used to improve the methods of monitoring NPP facilities.

Excitation-invariant pre-processing of thermographic data

2018 ◽  
Vol 232 (4) ◽  
pp. 435-446
Author(s):  
Serafeim Moustakidis ◽  
Athanasios Anagnostis ◽  
Apostolos Chondronasios ◽  
Patrik Karlsson ◽  
Kostas Hrissagis
Keyword(s):  
Composite Structures ◽  
Signal To Noise Ratio ◽  
Signal Reconstruction ◽  
Test Material ◽  
Test Surface ◽  
Nondestructive Testing Method ◽  
Uneven Heating ◽  
Processing Techniques ◽  
Inspection Techniques ◽  
Non Destructive

There is a large number of industries that make extensive use of composite materials in their respective sectors. This rise in composites’ use has necessitated the development of new non-destructive inspection techniques that focus on manufacturing quality assurance, as well as in-service damage testing. Active infrared thermography is now a popular nondestructive testing method for detecting defects in composite structures. Non-uniform emissivity, uneven heating of the test surface, and variation in thermal properties of the test material are some of the crucial factors in experimental thermography. These unwanted thermal effects are typically coped with the application of a number of well-established thermographic techniques including pulse phase thermography and thermographic signal reconstruction. This article addresses this problem of the induced uneven heating at the pre-processing phase prior to the application of the thermographic processing techniques. To accomplish this, a number of excitation invariant pre-processing techniques were developed and tested in this article addressing the unwanted effect of non-uniform excitation in the collected thermographic data. Various fitting approaches were validated in light of modeling the non-uniform heating effect, and new normalization approaches were proposed following a time-dependent framework. The proposed pre-processing techniques were validated on a testing composite sample with pre-determined defects. The results demonstrated the effectiveness of the proposed processing algorithms in terms of removing the unwanted heat distribution effect along with the signal-to-noise ratio of the produced infrared images.

scholarly journals Ultrasonic Non-destructive Prediction of Spot Welding Shear Strength

2018 ◽  
Vol 962 ◽  
pp. 012047
Author(s):  
R. Himawan ◽  
M. Haryanto ◽  
R.M. Subekti ◽  
G.R. Sunaryo
Keyword(s):  
Shear Strength ◽  
Spot Welding ◽  
Non Destructive

scholarly journals NON-DESTRUCTIVE CONTROL OF THE TENSILE STRENGTH OF THE METAL IN SHEARING

2020 ◽  
pp. 35-38
Author(s):  
M. M. Matlin ◽  
V. A. Kazankin ◽  
E. N. Kazankina ◽  
E. V. Kapinosova
Keyword(s):  
Tensile Strength ◽  
Test Material ◽  
Elastic Plastic ◽  
Non Destructive

The paper describes a technique for non-destructive determination of the tensile strength of a metal in shearing based on elastic-plastic introduction of an indenter into a test material.

scholarly journals The Analysis of the Post-Operation Microstructure and Mechanical Properties of the Similar Welded Joint

2020 ◽  
pp. 37-41
Author(s):  
Agata Merda ◽  
Klaudia Klimaszewska
Keyword(s):  
Mechanical Properties ◽  
Welded Joint ◽  
Base Material ◽  
Steam Pressure ◽  
Test Material ◽  
Quality Level ◽  
Fine Grained ◽  
Post Operation ◽  
Non Destructive ◽  
M23c6 Carbides

The test material was a specimen sampled from sections of a pipe operated for 41,914 hours at a temperature of 575°C and under a steam pressure of 28.2 MPa. The specimen subjected to metallurgical tests was a welded joint made of austenitic steel TP347HFG. The non-destructive tests and the macroscopic tests confirmed the lack of any welding imperfections. The test joint represented quality level B in accordance with related standard requirements. The microstructural tests of the heat-affected zone (HAZ) revealed the presence of the fine-grained austenitic structure with numerous precipitates on grain boundaries – probably M23C6 carbides. In spite of long-lasting operation, the mechanical properties of the test welded joint were high and did not exceed the standard-related requirements concerning the base material.

scholarly journals OPERATIONAL CONTROL OF THE LIMIT UNIFORM PLASTIC DEFORMATION

2020 ◽  
pp. 33-35
Author(s):  
M. M. Matlin ◽  
V. A. Kazankin ◽  
E. N. Kazankina
Keyword(s):  
Plastic Deformation ◽  
Structural Steels ◽  
Spherical Indenter ◽  
Operational Control ◽  
Plastic Properties ◽  
Elastic Plastic ◽  
Acceptable Accuracy ◽  
Plastic Indentation ◽  
Non Destructive

The paper presents a non-destructive method for determining the limit uniform narrowing of structural steels by the parameters of the elastic-plastic indentation of a spherical indenter. An acceptable accuracy of the method for engineering assessment of the plastic properties of the material of parts is shown.

scholarly journals DIAGNOSTICS OF THE PHYSICAL AND MECHANICAL PROPERTIES OF THE METAL BY THE PARAMETERS OF THE ELASTIC-PLASTIC INDENTATION OF A SPHERICAL INDENTER

2020 ◽  
pp. 58-62
Author(s):  
M. M. Matlin ◽  
V. A. Kazankin ◽  
E. N. Kazankina
Keyword(s):  
Mechanical Properties ◽  
Physical And Mechanical Properties ◽  
Spherical Indenter ◽  
Test Material ◽  
Tensile Stresses ◽  
Elastic Plastic ◽  
Plastic Indentation ◽  
Non Destructive ◽  
Destructive Methods

The paper describes non-destructive methods for determining the physical and mechanical properties of metals based on the regularities of elastic-plastic indentation of a spherical indenter into the test material. Using the proposed methods makes it possible to construct a diagram of true tensile stresses based on the results of a single indentation of a spherical indenter.

scholarly journals A New Proposal for the Shear Strength Prediction of Beams Longitudinally Reinforced with Fiber-Reinforced Polymer Bars

Buildings ◽  
2020 ◽  
Vol 10 (5) ◽  
pp. 86 ◽  
Author(s):  
Czesław Bywalski ◽  
Michał Drzazga ◽  
Mieczysław Kamiński ◽  
Maciej Kaźmierowski
Keyword(s):  
Shear Strength ◽  
Shear Capacity ◽  
Destructive Testing ◽  
Concrete Members ◽  
Reinforced Polymer ◽  
Proposed Model ◽  
Fibre Reinforced Polymer ◽  
Frp Reinforcement ◽  
Non Destructive ◽  
Frp Bars

This paper investigates composite reinforcement with regard to its use as longitudinal reinforcement. The methods used to calculate the shear strength of concrete members reinforced with fibre-reinforced polymer (FRP) bars are analysed. The main parameters having a bearing on the shear strength of beams reinforced with composite bars are defined. A comparative analysis of the shear strength calculating algorithms provided in the available design recommendations concerning FRP reinforcement and formulas derived by others researchers is carried out. A synthesis of the research to date on sheared concrete members reinforced longitudinally with FRP bars is made. The results of the studies relating to shear strength are compared with the theoretical results yielded by the considered algorithms. A new approach for estimating the shear capacity of support zones reinforced longitudinally with FRP bars without shear reinforcement was proposed and verified. A satisfactory level of model fit was obtained—the best among the available proposals. Taking into account the extended base of destructive testing results, the estimation of the shear strength in accordance with the proposed model can be used as an accompanying (non-destructive) method for the empirical determination of shear resistance of longitudinally reinforced FRP bars.

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