scholarly journals Influence of vibration loads on the strength of sheet composite elements of ship structures

2021 ◽  
pp. 43-47
Author(s):  
С.И. Корягин ◽  
Н.Л. Великанов ◽  
О.В. Шарков
Keyword(s):  
Strain State ◽  
Applied Load ◽  
Natural Vibration ◽  
Test Procedure ◽  
Experimental Studies ◽  
Polymer Coatings ◽  
Vibration Load ◽  
Urgent Task ◽  
Metal Plates ◽  
Vibration Loads

Использование листовых композитных элементов при ремонте судовых корпусных конструкций выдвигает как актуальную задачу определения влияния вибрационных нагрузок на прочностные характеристики конструкций с композитными элементами. Имеющиеся методики расчета металлических пластин под действием вибрационных нагрузок не могут быть применены для композитных элементов без дополнительных исследований. Разработаны установка и методика проведения экспериментальных исследований. Нагружения проводились циклами различной продолжительности. Представлены полученные зависимости предела прочности материала от числа циклов нагружения, При этом учитывалась ориентация исследуемых слоев относительно приложенной нагрузки. В процессе исследований установлено, что полимерные покрытия способны поглощать часть вибрационной нагрузки и изменять частоты собственных колебаний конструкции. Разработанная экспериментальная установка и методика испытаний позволяют опытным путем определить напряженно-деформированное состояние конструкции с композитными элементами. The use of sheet composite elements in the repair of ship hull structures puts forward as an urgent task to determine the influence of vibration loads on the strength characteristics of structures with composite elements. The available methods for calculating metal plates under the influence of vibration loads cannot be applied to composite elements without additional research. The setup and methodology for conducting experimental studies have been developed. The loads were carried out in cycles of different duration. The obtained dependences of the ultimate strength of the material on the number of loading cycles are presented, taking into account the orientation of the studied layers relative to the applied load. In the course of research, it was found that polymer coatings are able to absorb part of the vibration load and change the natural vibration frequencies of the structure. The developed experimental setup and test procedure allow us to determine the stress-strain state of the structure with composite elements by experimental means.

Experimental Studies Of Multilayer Glass Structures On Compression, Compression With Bending And Simple Bending

2019 ◽  
pp. 22-30
Keyword(s):  
Cross Section ◽  
Cross Sections ◽  
Applied Load ◽  
Experimental Studies ◽  
Strength Properties ◽  
Research Topic ◽  
Normative Values ◽  
Laminated Glass ◽  
The Cross ◽  
Experimental Values

The work of multilayer glass structures for central and eccentric compression and bending are considered. The substantiation of the chosen research topic is made. The description and features of laminated glass for the structures investigated, their characteristics are presented. The analysis of the results obtained when testing for compression, compression with bending, simple bending of models of columns, beams, samples of laminated glass was made. Overview of the types and nature of destruction of the models are presented, diagrams of material operation are constructed, average values of the resistance of the cross-sections of samples are obtained, the table of destructive loads is generated. The need for development of a set of rules and guidelines for the design of glass structures, including laminated glass, for bearing elements, as well as standards for testing, rules for assessing the strength, stiffness, crack resistance and methods for determining the strength of control samples is emphasized. It is established that the strength properties of glass depend on the type of applied load and vary widely, and significantly lower than the corresponding normative values of the strength of heat-strengthened glass. The effect of the connecting polymeric material and manufacturing technology of laminated glass on the strength of the structure is also shown. The experimental values of the elastic modulus are different in different directions of the cross section and in the direction perpendicular to the glass layers are two times less than along the glass layers.

Microbiological substantiation of application of phytopreparations in treatment of inflammatory periodontal diseases

2019 ◽  
Vol 24 (3) ◽  
pp. 196-202 ◽  
Author(s):  
S. A. Abdurakhmanova ◽  
G. S. Runova ◽  
M. S. Podporin ◽  
E. V. Tsareva ◽  
E. V. Ippolitov ◽  
...  
Keyword(s):  
Tooth Loss ◽  
Periodontal Diseases ◽  
Adult Population ◽  
Experimental Studies ◽  
Herbal Medicines ◽  
Growth Dynamics ◽  
Integrated Approach ◽  
Bacterial Populations ◽  
Streptococcus Constellatus ◽  
Urgent Task

Relevance: Inflammatory-destructive periodontal diseases are the most complicated and became the main cause of tooth loss in adult population. Herbal medicines have a variety of pharmacological properties, so the development and introduction of new forms for the treatment of inflammatory periodontal diseases is an urgent task today.Purpose – experimental evaluation of effectiveness of the use of herbal medicines “Tonzinal” and “CM-1” in relation to the priority periodontal pathogenes.Materials and methods: in experimental studies, the basis for the experiment was the system for the cultivation of microorganisms in real time – the Revers-Spinner RTS-1 bioreactor. With the priority strains of periodontitis pathogens, the study of the growth dynamics of the culture was carried out in several parallels.Results: herbal medicines “CM-1” and “Tonsinal” has a multilateral therapeutic effect, exerting a diverse influence on the key stages of development of such bacterial populations as Aggregatibacter actinomycetemcomitans, Streptococcus constellatus, Candida albicans.Conclusion: tan integrated approach in the treatment of patients with inflammatory periodontal diseases is promising and will contribute to a more prolonged remission and increase the effectiveness of treatment. 

Experimental modeling of adjacent parallel shield tunnels subjected to train-induced vibration loads

2021 ◽  
pp. 095440972098626
Author(s):  
Junchen Zhang ◽  
Qixiang Yan ◽  
Kai Yang ◽  
Minghui Sun
Keyword(s):  
Experimental Studies ◽  
Bimodal Distribution ◽  
Dominant Frequency ◽  
Experimental Modeling ◽  
Load Curve ◽  
Hilbert Huang Transform ◽  
Frequency Peak ◽  
Train Speed ◽  
Vibration Loads ◽  
Train Induced Vibration

Previous studies have performed numerical simulations of adjacent parallel shield tunnels under train-induced vibration loads. However, few experimental studies have been performed for the interaction mechanisms. In this study, experimental modeling is conduced to explore the interaction of adjacent parallel shield tunnels subjected to different train-induced vibration loads. A new Hilbert-Huang transform (HHT) is applied to obtain the instantaneous responses of tunnels. The results show that the acceleration of the tunnel follows the trend of the train load curve. The peak accelerations of the tunnels experience a unimodal distribution along the train speed, while the dominant frequencies of the tunnels follow a bimodal distribution. The interaction between the adjacent parallel tunnels is significant. The transform of the vibration loads to the adjacent tunnel is through the soil below the tunnel. The farther away from the train load is, the greater the train speed corresponding to the dominant frequency peak.

METHOD FOR DETERMINING THE LIMITS OF ELASTICITY AND PROPORTIONALITY OF MATERIALS FOR SUBSEQUENT DRILLING OF WORKPIECES IN THE STRESS–STRAIN STATE

2020 ◽  
Vol 3 ◽  
pp. 164-170
Author(s):  
V.V. KUTS ◽  
A.S. BYSHKIN ◽  
M.S. RAZUMOV
Keyword(s):  
Measurement Error ◽  
Elastic Deformation ◽  
Strain State ◽  
Drilling Process ◽  
Stress Strain ◽  
Workpiece Material ◽  
Stress Strain State ◽  
Urgent Task ◽  
Accuracy Of Measurement ◽  
Proportionality Limit

Drilling holes is one of the most common operations in the manufacture of parts. As a result, improving the efficiency of this process is an urgent task. To improve the efficiency of the drilling process, a method was developed at the Southwestern University for drilling with pre–stressed–deformed material of the workpiece, in which the sample is subjected to elastic deformation at a load that does not exceed the proportionality limit of the workpiece material, that is, when the load is removed, the dimensions of the workpiece remain the same. As part of this work, an experimental device was developed and designed to determine the limits of elasticity and proportionality of materials for subsequent drilling of workpieces in a stress–strain state. This invention will improve the automation and accuracy of measurement. An example of measurement and calculation is considered. Calculation formulas for determining the measurement error are given.

Studies of the Flame Spraying of Polymers

1996 ◽  
Author(s):  
D.J. Varacalle ◽  
K.W. Couch ◽  
V.S. Budinger
Keyword(s):  
Bond Strength ◽  
Combustion Process ◽  
Experimental Studies ◽  
Polymer Coatings ◽  
Flame Spraying ◽  
Knoop Microhardness ◽  
Resultant Coating ◽  
Strength Characterization ◽  
Thermally Sprayed

Abstract Experimental studies of the subsonic combustion process have been conducted in order to determine the quality and economics of polyester, epoxy, urethane, and hybrid polyester-epoxy coatings. Thermally sprayed polymer coatings are of interest to several industries for anti-corrosion applications, including the infrastructural, chemical, automotive, and aircraft industries. Classical experiments were conducted, from which a substantial range of thermal processing conditions and their effect on the resultant coating were obtained. The coatings were characterized and evaluated by a number of techniques, including Knoop microhardness tests, optical metallography, image analysis, and bond strength. Characterization of the coatings yielded thickness, bond strength, hardness, and porosity.

scholarly journals Investigation of the structure of cement conglomerates

2021 ◽  
Vol 266 ◽  
pp. 03005
Author(s):  
D. N. Shabanov ◽  
E. Trambitsky ◽  
E. Borovkova
Keyword(s):  
Strain State ◽  
Residual Life ◽  
Experimental Studies ◽  
Cement Stone ◽  
Virtual Model ◽  
Structural Studies ◽  
Acoustic Sensors ◽  
Cement Pastes ◽  
The Moment ◽  
Physical And Chemical

This article describes the structural studies of a cement conglomerate, its evolution from the moment of formation to the loss of operational properties. Physical and chemical phenomena and interactions of various elements of cement stone are considered. The study of its rheology includes creating a virtual model and monitoring the formation of the structure of cement pastes by acoustic emission (AE). The results of combined experimental studies to determine the residual life of cement stone samples using AE and tensometry methods are presented. The authors created a complex for monitoring the stress-strain state of artificial conglomerates, which includes both internal and acoustic sensors.

scholarly journals INVESTIGATION OF THE METHOD OF PROCESSING HOLES WITH A ROTARY CUP CUTTER WITH SURFACING

2021 ◽  
pp. 1-6
Author(s):  
Bakytzhan Donenbayev ◽  
Karibek Sherov ◽  
Assylkhan Mazdubay ◽  
Aybek Sherov ◽  
Medgat Mussayev ◽  
...  
Keyword(s):  
Surface Roughness ◽  
Cutting Tool ◽  
Large Diameter ◽  
Cutting Tools ◽  
Experimental Studies ◽  
Surface Hardness ◽  
Hard Metal ◽  
Metal Plates ◽  
Study Results ◽  
The Cost

This article presents the experimental study results of the process of rotational friction holes boring using a cup cutter surfaced by STOODY M7-G material. As a result of experimental studies, the following quality indicators were achieved: surface roughness within Ra=10÷1,25 micrometer; surface hardness within HB 212-248. Using a cup cutter surfaced by STOODY M7-G material in case of rotational friction boring of large-diameter holes for large-sized parts can improve processing performance in comparison with cutting tools equipped with hard metal plates and provided the required surface roughness. Preliminary calculations showed that the manufacture of cup cutters from non-instrumental materials reduces the cost of the cutting tool by 5-7 times and the cost of the operation by 1.5-2 times.

scholarly journals Numerical simulation of the stress-strain state of complex-reinforced elements

2019 ◽  
Vol 13 (2) ◽  
pp. 110-115
Author(s):  
Olena Krantovska ◽  
Mykola Petrov ◽  
Liubov Ksonshkevych ◽  
Matija Orešković ◽  
Sergii Synii ◽  
...  
Keyword(s):  
Numerical Simulation ◽  
Strain State ◽  
Theoretical Calculations ◽  
Experimental Studies ◽  
Theoretical Studies ◽  
Stress Strain ◽  
Narrow Strip ◽  
Stress Strain State ◽  
Graphical Environment ◽  
Experimental And Theoretical Studies

The article describes a developed technique of a numerical simulation of the stress-strain state of complex-reinforced elements, which allows you to create models of double-span continuous. The performed experimental and theoretical studies allowed us to carry out the testing of the developed design model and to justify the reliability of the proposed numerical simulation methodology. The results of the experimental studies were compared with those of the theoretical studies. The theoretical calculus algorithm was developed by using the finite element method. Theoretical calculations were performed by using the mathematical-graphical environment software system LIRA-SOFT and the mathematical and computer program MATLAB. On the basis of the experimental research, the iso-fields of displacements and stresses in the materials of an eccentrically compressed beam with a small bend of the slab were constructed, which collapse behind the inclined narrow strip of concrete and displacements and stresses in the materials of the eccentrically stretched beam, which is destroyed due to the yield of the upper mounting armature.

Porous Polymer Coatings Based on Nitrocellulose

2019 ◽  
Vol 968 ◽  
pp. 68-75
Author(s):  
Valeriy Vyrovoy ◽  
Viacheslav Bachynckyi ◽  
Nadia Antoniuk
Keyword(s):  
Porous Structure ◽  
Cellular Structure ◽  
Polymer Coating ◽  
Experimental Studies ◽  
Polymer Coatings ◽  
Porous Polymer ◽  
Polymeric Coatings ◽  
New Approach ◽  
Porous Coatings

The paper presents the development of optimum structures and the production of polymeric coatings technology which can absorb aggressive substances. The studies of coatings penetrating into the film are presented due to the organization of their capillary-cellular structure by introducing special fillers. A new approach to solve the problem of protecting the environment, people, buildings and structures from the effects of aggressive substances has been proposed. The essence of the method consists in the preventive deposition on the surfaces of construction objects of porous coatings that can irreversibly absorb aggressive substances. Based on theoretical and experimental studies, porous coatings have been developed that are capable of accumulating in their volume aggressive substances, as well as certain principles of providing the coating with the necessary capillary-porous structure. The mechanism of creating a capillary-cellular structure of a polymer coating based on nitrocellulose are substantiated.

scholarly journals Experimental studies of hole drilling operations in stress-strain workpiecematerial

2018 ◽  
Vol 226 ◽  
pp. 01011
Author(s):  
Vadim V. Kuts ◽  
Mikhail S. Razumov ◽  
Aleksandr S. Byshkin
Keyword(s):  
Axial Force ◽  
Experimental Studies ◽  
Hole Drilling ◽  
Drilling Process ◽  
Stress Strain ◽  
Workpiece Material ◽  
South West ◽  
Urgent Task ◽  
Drilling Operations ◽  
Proportionality Limit

Drilling holes is one of the most common operations in the part production. Consequently, increasing the efficiency of this process is an urgent task. To improve the efficiency of the drilling process, the South- West University developed a method of drilling for pre-stressed and prestrained workpiece material, which requires a sample to be subjected to elastic strain under load not exceeding the proportionality limit of the workpiece material. That is, when the load is removed, the dimensions of the workpiece remain unchanged. The paper presents the experimental device designed to determine the axial force and torque when drilling holes in the stress-strain workpiece material. Multi-factor experiments were carried out to obtain empirical dependences of the axial force and torque arising in drilling holes in the stress-strain workpiecematerial on the process parameters.

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