scholarly journals Calibration testing of discs using photoelasticity method

2018 ◽  
Vol 251 ◽  
pp. 04055
Author(s):  
Ludmila Frishter
Keyword(s):  
Composite Structures ◽  
Mechanical Characteristics ◽  
Model Material ◽  
Test Method ◽  
Compatibility Conditions ◽  
Disk Model ◽  
Photoelasticity Method ◽  
Temperature Deformations ◽  
Definition Of ◽  
Composite Disk

Using of the photoelasticity method for determining the stresses under the action of specified forced deformations and, in particular, temperature deformations, which do not satisfy the compatibility conditions, is relevant in the study of composite structures. Photoelasticity method, which is a continual method, and the method of “defrosting” forced deformations, as its subsection, allow obtaining a stress-strain state in the composite area with forced deformations on models made of optically - responsive material. The method of defrosting forced deformations, using the procedure of preliminary freezing of model elements with subsequent defrosting of the entire model, is an effective, versatile and promising method for simulation of stresses as a result of specified forced deformations. In the study of composite structures by the method of photoelasticity and defrosting “defrosting” of forced deformations, a model composed of elements with previously created forced deformations is created. To determine the created forced deformations, calibration tests are performed, in which the following actual loads are determined: forced deformations, pressure, optical and mechanical characteristics of the model material: modulus of elasticity, material fringe value. Novelty of the calibration test method is the definition of “frozen” forced deformations in the blank of the photoelasticity model using a single composite disk model without testing additional models - beams [1, 2]. Taken into account the material parameters of model: Young's modulus, the price of a polymeric material strip, which are different for batches of initial components: epoxy resin and anhydrite. In order to approve the results of calibration tests, this paper considers the theoretical and experimental solution of the elasticity test problem for a composite disk, one of the areas of which is uniformly heated. The obtained data are used for calibration tests in determining the actual loads and mechanical characteristics in the model sections.

Research the Test Method of the Voltage Transformer Secondary Load in the Three-Phase Three-Wire Electric Energy Metering Device

2014 ◽  
Vol 687-691 ◽  
pp. 3110-3115
Author(s):  
Gu Li ◽  
Zi Ming Fu ◽  
Jie Feng Yan ◽  
Bing Wen Li ◽  
Zhi Rong Cen
Keyword(s):  
Power Supply System ◽  
Electric Energy ◽  
Test Methods ◽  
Test Method ◽  
Testing Methods ◽  
Voltage Transformer ◽  
Secondary Load ◽  
Three Phase ◽  
Energy Metering ◽  
Definition Of

This paper analyzes and studies the definition of the voltage transformer secondary load, examines the practical purposes of the measured values of the voltage transformer secondary load, and presents a variety of testing methods to analyze and compare the differences. This paper gives the test methods of the voltage transformer secondary load when the connection of the voltage transformer is the Y / Y in a three-phase three-wire power supply system, filling the blank of this type of test method in the industry. When other units within the industry carry out such work, the conclusions of this paper are available for reference, and the conclusions of this paper can be referred when drafting relevant regulations in the future.

scholarly journals Improvement of Accuracy of Control of Physical‑Mechanical Characteristics of Materials By Ultrasonic Pulse Method Due to Reduction of Measurement Error of Propagation Time of Elastic Waves

2018 ◽  
pp. 31-35
Author(s):  
Ya. Serikov
Keyword(s):  
Mechanical Characteristics ◽  
Pulse Method ◽  
Structural Heterogeneity ◽  
Ultrasonic Pulse ◽  
Ultrasonic Signal ◽  
Ultrasonic Transducers ◽  
Propagation Time ◽  
Information Signal ◽  
Pass Through ◽  
Definition Of

Ensuring the reliability of buildings, structures, analysis of their structural elements during reconstruction or major repair includes the task of determining the physical and mechanical characteristics of materials — strength, homogeneity, evaluation of structural heterogeneity, the presence of microcracks, etc. In solving this problem, an ultrasonic pulse method of non-destructive quality control is used. The basis of the method is the dependence of the parameters of ultrasonic oscillations, on these characteristics when they pass through the material. As the main parameter of the information ultrasonic signal, the time of its passage from the radiating to the receiving ultrasonic transducers is used. The amplitude of the information ultrasonic signal to a large extent depends on the structure of the investigated material, its acoustic resistance. At significant violations of the structure of the material there is a significant decrease in the amplitude of the information signal, which causes an increase in the error of measuring the time of its passage, and hence the definition of characteristics, quality of the investigated material. The article describes the developed method of increasing the accuracy of measuring the time of passage of the ultrasonic signal from the radiating to the receiving ultrasonic transducers. The essence of the technique is to use the mathematical modeling of the shape of the ultrasound signal, in particular the form of its so-called «first introduction».

scholarly journals KONSISTENSI AKSIOMA-AKSIOMA TERHADAP ISTILAH-ISTILAH TAKTERDEFINISI GEOMETRI HIPERBOLIK PADA MODEL PIRINGAN POINCARE

EDUPEDIA ◽  
2018 ◽  
Vol 2 (2) ◽  
pp. 161
Author(s):  
Febriyana Putra Pratama ◽  
Julan Hernadi
Keyword(s):  
Half Plane ◽  
Hyperbolic Geometry ◽  
Euclidean Geometry ◽  
Cross Ratio ◽  
Literature Study ◽  
Disk Model ◽  
Non Euclidean Geometry ◽  
The Cross ◽  
Definition Of ◽  
Poincaré Disk

This research aims to know the interpretation the undefined terms on Hyperbolic geometry and it’s consistence with respect to own axioms of Poincare disk model. This research is a literature study that discusses about Hyperbolic geometry. This study refers to books of Foundation of Geometry second edition by Gerard A. Venema (2012), Euclidean and Non Euclidean Geometry (Development and History)  by Greenberg (1994), Geometry : Euclid and Beyond by Hartshorne (2000) and Euclidean Geometry: A First Course by M. Solomonovich (2010). The steps taken in the study are: (1) reviewing the various references on the topic of Hyperbolic geometry. (2) representing the definitions and theorems on which the Hyperbolic geometry is based. (3) prepare all materials that have been collected in coherence to facilitate the reader in understanding it. This research succeeded in interpret the undefined terms of Hyperbolic geometry on Poincare disk model. The point is coincide point in the Euclid on circle . Then the point onl γ is not an Euclid point. That point interprets the point on infinity. Lines are categoried in two types. The first type is any open diameters of   . The second type is any open arcs of circle. Half-plane in Poincare disk model is formed by Poincare line which divides Poincare field into two parts. The angle in this model is interpreted the same as the angle in Euclid geometry. The distance is interpreted in Poincare disk model defined by the cross-ratio as follows. The definition of distance from  to  is , where  is cross-ratio defined by  . Finally the study also is able to show that axioms of Hyperbolic geometry on the Poincare disk model consistent with respect to associated undefined terms.

Study oil density in flow, system of automated measurement and inaccuracies

2020 ◽  
pp. 39-44
Author(s):  
M.M. Isayev ◽  
◽  
M.B. Mammadova ◽  
N.M. Khasayeva ◽  
F.Sh. Aghayeva ◽  
...  
Keyword(s):  
Measurement Errors ◽  
Automatic Measurement ◽  
Test Method ◽  
Measuring Accuracy ◽  
Fuel Density ◽  
Oil Pipelines ◽  
Operation Algorithm ◽  
Test Equation ◽  
Oil Density ◽  
Definition Of

The paper reviews the issues of specification of fluid fuel amount with high measuring accuracy transported through oil pipelines. The operation algorithm of vibration-frequency densitometer for automatic measurement of fluid fuel density with high measuring accuracy in technological process in the exploitation conditions is based on the hybrid test method. For this purpose test equations on measuring links using simple additive and multiplicative tests, as well as their combinations have been developed, test equations composed, and as a result of their solution the main test equation obtained. The mathematic-statistic estimation of the results of densitometer measurements correcting test algorithms for the definition of measurement errors and composing inaccuracies, the method of automated calibration are presented as well.

scholarly journals Calculation of composite elements of slabs in buildings, structures and fragments of spans of bridges

2018 ◽  
Vol 230 ◽  
pp. 02007 ◽  
Author(s):  
Stanislav Fomin ◽  
Yuriy Izbash ◽  
Serhii Butenko ◽  
Maryna Iakymenko ◽  
Karina Spirande
Keyword(s):  
Bearing Capacity ◽  
High Temperatures ◽  
Composite Structures ◽  
Strain Ratio ◽  
Strain Diagram ◽  
Stress Strain ◽  
Maximum Deformation ◽  
Definition Of ◽  
Two Stages ◽  
The Mathematical Model

The calculation consists of two stages. The first one begins with the definition of their class, bearing capacity at temperature of 20 °C, according to EN 1992-1-1. At the second stage, the calculation at high temperatures shall be carried out in accordance with Eurocode 4 part 1-2. Comparison of the “stress-strain” diagram of concrete of class 30 under compression and temperature of 20 °C in two formulas showed their difference. That is, the designers do not have the opportunity to continue the calculation of diagrams at different heating temperatures. There was a need to improve the mathematical model of the “stress-strain” ratio of concrete high temperatures, clarification of the criteria of the bearing capacity of concrete in calculation of the fire resistance of composite structures in EN 1994-1-2:2005. In this paper, the method of determination of εcu1,θ developed has allowed, based on the energy approach, to formulate the corrected dependence of the limit deformation on temperature, dependence of the maximum deformation on temperature, and the value of the parameters of the “stress-strain” diagram. According to these data, using the formulas of the first stage, the “stress-strain” diagrams of the concrete of class 30 are calculated at the compression and heating according to EN 1992-1-2:2004.

Review of material test standardization status for the material qualification of laminated thermosetting composite structures

2020 ◽  
pp. 073168442095810
Author(s):  
Sang Yoon Park ◽  
Won Jong Choi
Keyword(s):  
Composite Materials ◽  
Material Properties ◽  
Composite Structures ◽  
Failure Modes ◽  
Laminated Composite ◽  
Test Methods ◽  
Test Method ◽  
Experimental Comparison ◽  
Laminated Composite Materials ◽  
Design Values

This paper presents a review of recent literature related to the static mechanical testing of thermoset-based carbon fiber reinforced composites and introduces a material qualification methodology to generate statistically-based allowable design values for aerospace application. Although most test methods have been found to be effective in determining the specific material properties by incorporating them into the material qualification and quality control provisions, a full validation to clarify the behavior of thermoset-based laminated composite materials is currently lacking, particularly with regard to the characterization of compressive, in-plane, interlaminar shear, and damage tolerance properties. The present study obtains information on the different types of test method that can be employed within the same material properties, and makes an in-depth experimental comparison based on the past literatures. A discussion on the scope of theoretical analysis involves a description of how the proposed test method can be adequate for obtaining more accurate material properties. This discussion is directly applicable to the assessment of material nonlinearity and the geometrical effect of specimens. Finally, the resulting failure modes and the effect of each material property are studied to aid the understanding of the load distribution and behavior of laminated composite materials.

Study of Strength and Deformation Properties of the Composite Reinforcing Bar from the Continuous Basalt Fiber

2020 ◽  
Vol 1013 ◽  
pp. 132-138
Author(s):  
L.Yu. Stupishin ◽  
S.G. Emelyeanov ◽  
E.V. Savelyeva ◽  
M.L. Moshkevich
Keyword(s):  
Composite Structures ◽  
Test Procedure ◽  
Basalt Fiber ◽  
High Strength ◽  
Test Method ◽  
Strength Characteristics ◽  
Reinforcing Bar ◽  
Low Weight ◽  
Deformation Properties ◽  
Weight One

Composite structures require the use of modern reinforcing materials combining high strength characteristics and resistance to aggressive influences with low weight. One of the promising materials for the production of reinforcing products is basalt roving. The high strength of the thread in combination with fragility imposes certain limitations on its placement in the material, and requires new approaches to the design of the reinforcing bar itself. The article investigates the strength characteristics of a composite reinforcing bar made of a basalt complex thread proposed by the authors. The features of the test procedure and the mechanical characteristics of the reinforcing material are described. The effectiveness of the applied test method developed in the process of testing reinforcing rods is shown. An increase in the tensile strength of a composite reinforcing bar based on basalt fiber is established in comparison with products from fiber and roving.

Possibility of Usage of Aluminium Rivet Nuts Connections in Composite Materials

2015 ◽  
Vol 240 ◽  
pp. 137-142 ◽  
Author(s):  
Radosław Bielawski ◽  
Michał Kowalik ◽  
Karol Suprynowicz ◽  
Paweł Pyrzanowski
Keyword(s):  
Composite Materials ◽  
Tensile Test ◽  
Composite Structures ◽  
Test Method ◽  
Damage Models ◽  
Constant Torque ◽  
Composite Damage ◽  
Composites Materials ◽  
Riveted Joints ◽  
Static Tensile

Development and application of composite materials in modern industry are very dynamic. Composite materials seem to be replacing steel and aluminium ones. Composites are a cheaper solution, with similar mechanical strengths. Generally, there are two types of joints in composite structures: mechanical and adhesively bonded ones. The aim of the study was to determine the feasibility of riveted joints in composites materials. Static tensile test method was used. In the test there was used one type of glass fabric (Interglas 92140) from which two types of composite samples were prepared. In each sample there was used the same type of fiber with the same fiber orientation – 3 layers. Samples had dimensions of 220x100 mm and thickness of approximately 1.5 mm. They were connected to each other with aluminium rivet nuts (from 1 to 3) and placed in a metal frame with a screw connection which was made of screws with nominal thread pitch M5. Screws were tightened with constant torque. It was to provide an axial force to the sample during the tensile test. The frame was placed between cross-bars of tensile machine INSTRON 8516. The samples were stretched at a speed of 0.05 mm/s at a distance up to 20 mm. During the tensile test displacement of the samples and pull force were registered. Depending on the fiber orientations and number of rivet nuts composite damage models were described. On the basis of the results the possibility of usage of aluminium rivet nuts connections in composite materials was determined.

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