bluuebunny/crossref_metadata_2025 huggingface dataset:
THE CONTRIBUTION OF UNIVERSITIES OF THE SOUTH OF RUSSIA IN THE RESTORATION OF ITS MINING POTENTIAL
Authors: Razorenov Y. I. , Shulgaty L. P. , Dzeranov B. V.
Published: July 2018

Given the historical background of ore and non-ore fields of the South of Russia, the reasons for their current state. Set the problem field development of the South of Russia, namely, the weakening in the rate or complete cessation of their operation in the post-reformation era. The role of mining UNIVERSITIES in the South of Russia in scientific and technical progress of mining in the North Caucasus during the development of the natural resources that form the mineral resource base of the Russian statehood. Formulated the concept of technological modernization of mining technology as the program of converting from mining to non-traditional technology. Contents of changes in the system of higher education, which was enriched with new sections of Sciences, which required the intensification of the educational process. Characterized the position of the Federal districts of the South of Russia in mineral resources base of Russia. The characteristic of large ore and non-ore deposits with the allocation of values Zadonskogo and Tyrnyauz fields. Given historical background of education, Novocherkassk Polytechnic Institute, and North-Caucasian Institute of non-ferrous metals and their contribution of groups in research and training engineers for the mining industry. Announced directions of perfection of technology of extraction of ore and nonmetallic raw materials with the use of selective excavation of ore, leaching of poor and substandard ore and disposal of metal mining waste production, leaching into the cage. The peculiarities of the training of mining engineers. Formulated the aim of education in the mountain schools of the South of Russia which is to teach mountain professionals the humane treatment of nature, and the ability to participate in environmental protection and rational use of natural resources.
INSTITUTIONAL CONDITIONALITY OF DEVELOPMENT OF SOVREMEN-NYH OF ECONOMIC SYSTEMS
Authors: Babayan Y. V.
Published: July 2018

Approaches of the institutional theory to differences between hierarchical and market mechanisms of economic interactions are researched. affirms that modern evolution leads to deleting of borders between these two forms and to their mutual interlacing. The research of the fundamental principles of organizational forms and coordination of economic activity as in each of two main forms of cooperation of economic actors - the organization (hierarchy) and the market, and between them is one of basic elements of modern economic science. With respect thereto there is a question of basic differences between them, their borders and forms of interactions. the existing universal typology not absolutely precisely reflects reality. The entities aren’t capable to perform complete optimization of transactional expenses because of complexity and the uncertainty of the environment, and also owing to limited rationality making the decision. Therefore the choice of this or that organizational “ideal model" is utopian as borders of the entities don’t give in to a limitation in connection with variety of the purposes, interdependence of actions of other economic actors as components of the external environment. The state stimulation of these or those links of economic system shall be aimed at the development not of the separate entities, but market structures in general into which they enter only as components.
AGRICULTURAL INDUSTRY OF KUBAN DURING THE PRE-WAR PERIOD OF 19371940: INDICATORS AND PROBLEMS OF DEVELOPMENT
Authors: Zakharova I. Y. , Melikyan K. V.
Published: July 2018

N article the main directions of development of industries of agricultural industry of Krasnodar Krai during the period from 1937 to 1940 are considered. The main tendencies of development of industries of crop production (grain crops, sunflower, a castor-bean tree, cotton, rice, fodder herbs, efiro-olive) and livestock production (horse breeding, sheep breeding and pig-breeding) of Kuban during the pre-war period on districts of the region are revealed. The number of the entities (kolkhozes) having a certain direction of specialization is revealed (grain, olive, beet, fruit and vegetable, cotton, bast, tobacco). The sizes of separate industries of agricultural industry are determined by sectors (kolkhozes and sovkhozes). The specific weight of grain crops in the general structure of sown areas of Kuban is considered. Acreage and productivity of wheat, corn, sunflower, a castor-bean tree, peanut, sesame, soy, a coriander, tobacco, sugar beet, rice, cotton, hemp are revealed. Development of melon growing, vegetable growing and fruit growing in Kuban is considered. The problems arising in areas and in the territory of Krasnodar Krai in general, connected with placement of acreage and specialization of cultures, and also with development of industries of livestock production are revealed. Solutions of further development of industries of economy are determined and developed actions for liquidation of the problems arising in agricultural industry of Kuban are analysed.
PROFESSIONAL STANDARDS: SPECIFICS OF IMPLEMENTATION IN THE RUSSIAN FEDERATION
Authors: Ladauskas S. V. , Sorokina N. V.
Published: July 2018

Currently at the forefront in the development of labour legislation beyond the introduction of professional standards, namely directly regulatory, information provision and decision of issues of legal regulation, improvement of the existing system of qualification requirements to the employees about what will be discussed in this scientific article. Due to the fact that Russian labour legislation does not contain many of the concepts, terms, procedural provisions and the order of introduction of qualification requirements for employees upon hiring, determining work func tions and stuff that is hampering the implementation of main goals and tasks of labour legislation. From July 2016 in Russia, the time has come for professional standards, entered into force article 195.1-195.3 of the Labor code governing the professional standards of the Ministry of labor of Russia (Federal law No. 122-FZ of 2.05.2015). From that time the workers have to regularly confirm their professional satisfaction. In the existing handbooks and the literature requirements for workers is often inaccurate and infrequently updated, and it directly is an important gap to resolve which applied to professional standards, detail of which will be discussed in this scientific article.
THE CURRENT STATE OF THE AUDIT MARKET IN RUSSIA
Authors: Roshchektayeva U. Y.
Published: July 2018

In the Russian Federation since the 1990s, the state tried to create a system of independent auditing: preparing for the auditors, formed the audit organization determined the list of their activities were confined to professional duties, rights and responsibilities of auditors in accordance with legislative acts, including rules (standards) of audit. However, still remain problematic issues of theory, methodology and methods, including definition of the essence of audit, control objects, object of knowledge, principles and functions. Requires justification also questions of development of methodology of audit by clarifying its requirements, tenets and elements of the system. The development of market relations in the economy, processes of globalization, the emergence of new organizational and legal forms of economic entities and diverse forms of ownership have had an impact on the mechanism of economic control in the Russian Federation, which became one of the most important elements of a market economy that actually performs the function of managing of economic subjects. One of the most important, promising and effective economic control of financial and economic activities of commercial organizations in a market is independent control - audit.
PRIORITY DIRECTIONS OF REALIZATION OF THE INSTRUMENTS FOR FINANCING SMALL AND MEDIUM ENTERPRISES IN MODERN CONDITIONS: REGIONAL COMPARISON
Authors: Vishnyakov I. P.
Published: July 2018

The article considers the problem of supporting small and medium businesses in the southern Federal district and Rostov region. The topic is relevant, because on small and medium enterprises hold the economy of the developed countries. The development of the microcredit sector in Russia and market development of financial services requires the theoretical study and practical resolution of issues that are associated with the organization levers of the financial interaction between the public and private sectors of the economy, the development of the legal base and state regulation. Special attention is paid to the problem of microcrediting of small businesses, with a description of regional programs of support and analysis specific amounts of subsidies and microcredit, the conditions of issuance, etc.. The specifics of microfinance organizations and credit organizations of a special kind, their special role and positive impact on the economic processes in Russia, which is reflected in the demand for loans to enterprises medium and small businesses and strengthening the flow of capital through the provision of loans to enterprises of the real sector of the economy, and participation in the transformation of the banking system, to ensure the flexibility of the financial system and the functioning of the differentiated structure of the banking organizations in Russia.
RATIONING SYSTEM IN KUBAN DURING THE POSTOCCUPATIONAL PERIOD OF 1943
Authors: Lazovskaya S. V. , Pavlova G. Y.
Published: July 2018

In article the organization of a rationing system in the territory of Krasnodar Krai during the period after the German occupation since February, 1943 is considered. After liberation of Kuban it was necessary to adjust life and work of the big region and also in the shortest possible time to begin supply of food and industrial goods for soldiers of the Red Army. Deliveries of agricultural production laid down a heavy burden on shoulders of the population of the region. In many areas people was on the verge of hunger: crops grain and potatoes in July, 1942 were destroyed by the receding Red Army, and a new harvest wasn’t grown up even on private farmsteads yet; production of trophy food warehouses was given to Red Army men, in areas there was no draft force. For improvement of a situation, in the territory of the region the rationing system which provided distribution of products and essentials among the population was introduced. The fact of restoration of rated supply played the important stabilizing role. Along with a rationing system the Krasnodar krayispolkom made the decision on distribution of the single help in the size of 300 rub to family and also the person in need and children of the military personnel single coupons on receiving a dry ration. Special attention from the regional authorities was paid to children, expressed in the organization of free food, providing with necessary clothes and footwear. In article the measures for toughening of control from the state connected with functioning of the commercial enterprises of food, revelry of the market relations and also moonshinings are considered. The rationing system introduced in Kuban during the period after occupation allowed to stabilize a situation and supported the population during the difficult period.
EVALUATION OF THE PROCESS OF PRICING WITH THE USE OF THE SELECTION OF THE PRICING STRATEGY OF THE FIRM AND DISCOUNTS
Authors: Chernyavskaya E. Y. , Pluzhnikova P. A. , Tatarenko A. A.
Published: July 2018

In the article the authors consider the pricing process at different firms, where price strategies and discounts are used to attract potential buyers and maximize profits. The authors evaluate the most common types of pricing strategies and discounts, trying them on the analyzed companies. As a methodological basis for the study, federal-wide general scientific methods have emerged, as the collection of important economic categories analysis, the year the logical approach is essential to the assessment of the economic year of phenomena, the comparison factors of the studied indicators. The authors of the article evaluate the existing price strategies, which are sufficient number, respectively, for firms to not get confused with the choice, they need a specific study of them. Different types of price strategies allow in market situations to choose the most optimal option, which is necessary in specific conditions. In turn, the seller gives discounts, promotes sales, which, inherently, has an impact on the amount of revenue and creates an attractiveness of the company, firm or other object, that is why the formation of discounts is not only the main element of price policy, but also the method used for creation of financial policy of the organization.
FINANCIAL RISKS IN THE SYSTEM OF MANAGEMENT OF INTANGIBLE ASSETS OF COMPANIES
Authors: Artemenko D. A. , Vorobyova A. V.
Published: July 2018

In conditions of growing competition, the importance of intangible assets to Russian companies is justified by necessity of regular improvement of risk management techniques associated with the management of IA and punishable by financial and information losses. In today’s dynamically changing economic situation in the country increases the degree of importance of the study of the effect of those risks on the value of intangible assets of the company, and identifying ways to protect against these risks. Timely identification of risks affecting the value of intangible assets allows to avoid financial losses and reduce costs to cover the consequences of these risks. Such consequences are the factor of universality of risks that are probabilistic. The universality of risk is manifested in the fact that they are not the random result of a conscious activity, a necessary condition for the existence of any company. Hence the structure of the risk management system is an indispensable necessity for effective activity of any enterprise. This is justified by the systematic risk and is considered as a property characteristic of all types of economic activity of enterprises. The diversity of forms and ways of manifestation of the risks as well as the variety of methods of assessment is determined by the absence of systematic approaches to risk management.
KEY FACTORS OF FORMATION OF SCIENTIFIC AND COMMUNICATIVE CAPACITY IN THE PROCESS OF TEACHING THE DISCIPLINE “RUSSIAN LANGUAGE AND SPEECH CULTURE” IN A NON-PHILOLOGICAL UNIVERSITY
Authors: Fedotova T.
Published: July 2018

In article the problem of forming of scientific potential in the course of development of discipline “Russian and the standard of speech" in not philological higher education institution is considered. In addition to interpretation of a modern line item of such concepts as scientific competence, the scientific potential, innovative technologies, the author sets the task scientific and pedagogical judgment of methods and methods of the effective organization of scientific cognitive activity of students, and also forming at the trained intellectual qualities and acceptances of generation and reproduction of new knowledge. On the example of teaching linguistic discipline questions of emergence of changes in the cogitative functions of the student allowing to manage effectively an information and intellectual resource are discussed. A condition of the problem resolution is implementation of innovative forms of knowledge acquisition and development of scientific potential, development of scientific and humanitarian thinking of the students included in scientific information space. Use of the principle of problem training acts as such innovations.
EXERIENCES WITH CONGINTIVE MECHANISMS IN TEACHING FOREING LANGUAGE
Authors: Anisimova A. T.
Published: July 2018

The article describes the experiences of applying cognitive linguistic approach to development of learners foreign language competence. It is suggested that the introduction of new language material should be based on conceptual representations (senses) of language forms rather than on comparability of native and foreign languages. Behind the cognitive approach to teaching foreign language there is a proposition that language is connected with reality or one of the possible realities through interpreting activity of an individual. The author discusses such issues of cognitive science as knowledge representation, information processing, development of language consciousness and individual learning styles in relation to teaching Russian learners a foreign language. The article describes the experiences of using cognitive mechanisms in development of effective tools in teaching a foreign language, in particular such topics as the system of the English article, teaching learners new foreign language vocabulary, usage of polysemantic words. The enhancement of language didactics paradigm with cognitive issues appears to be beneficial not only in learning a foreign language but also in development the learners general discursive competence.
MANAGEMENT OF PROFILE FACTORS OF MODERNIZATION OF INDUSTRIAL ENTERPRISES
Authors: Abelian H. S. , Ivanova N. E.
Published: July 2018

In the article, using econometric methods to analyze various aspects of identification of relevant factors of modernization of industrial enterprises, determined the most effective relations between them, their ranking is carried out. The paper provides an understanding of the role and place of the accelerated technological modernization of the industry as one of the imperatives of the state socio-economic strategy that currently updates the problem identification forms, mechanisms, strategies to build domestic industrial capacity. Along with this, SMEs require clear mechanisms of organizational-economic providing of the implementation of comprehensive modernization, including taking into account the specifics of the industrial complex and the accumulated socio-economic potential of the region. This predetermines the importance of the formulation of problems of organizational-economic providing of processes of technological modernization of the industry at the regional level. Discusses the changes in the process of modernization: the emergence of the latest procedures and devices of resolving social problems on the basis of improvement of all system of public relations and modification of way of life the emergence of innovative technologies; development of commodity-money relations, the acquisition of the highest level of professional expertise of managers and employees; the modification of social relations. The generalized algorithm effective management of the enterprise in terms of innovation, the tools identify the time lags of development of the enterprise. It is concluded that the identification of the relevant factors provides the possibility of optimizing the process of active management of innovative activity taking into account the stage of development of the enterprise.
HIGHER EDUCATION SYSTEM IN THE USA
Authors: Filipovich I. I.
Published: July 2018

The aim of the article is to analyze the system of Higher Education in the USA. It reviews the kinds of educational institutions and types of education which they provide. The system of Higher education in the United States of America is made up of two levels or stages. The first level is undergraduate education and when students complete it they usually become Bachelors of Art or Bachelors of Science. The second level is called postgraduate education which is completed with acquiring Master or Ph.D. degrees. There are several types of higher educational institutions such as colleges, universities, 2-year community colleges, conservatories, art schools, military academies and others. To be admitted in each level of higher education students have to take some certain standardized tests and prove their ability to manage the educational program. The article describes the system of funding of the USA higher education. The educational institutions can be categorized into public, private and for-profit schools. Private and for-profit colleges and universities are the most expensive schools. Students pay for tuition, room and board with their own money. There is a system of educational loans, scholarships and grants which you can take or receive if you do not have enough of your own finance. Americans are willing to pay for the education of their children as well as their own. It has to do with their belief that education will enable them to achieve success and financial stability. Many Americans follow the lifelong learning for professional growth, new knowledge and skills.
INTELLECTUAL CAPITAL OF THE ORGANIZATION: ITS CONCEPT AND ESSENCE
Authors: Ermishina E. B. , Orel E. V.
Published: July 2018

The concept of human capital was introduced by Adam Smith and John Stuart Mill, who understood the quantity and quality of a person’s ability to work under him. In the scientific revolution this concept was introduced by D. Gilbert in the late 60’s. XX century. The theory of intellectual capital was further developed on the basis of the development of the theory of human capital. The article deals with modern concepts of human capital, which became the basis for substantiating the decisive role of a person, his abilities and potential in creating the value of a concrete organization and social progress. Much attention is paid to the structure of intellectual capital, which is represented by a combination of human, organizational and consumer capital; comparison of intellectual capital with physical is given.
PROBLEMS OF INNOVATIVE DEVELOPMENT OF THE RUSSIAN FEDERATION
Authors: Saprykina V. Y. , Degtyarenko E. A.
Published: July 2018

Some researchers call the modern stage of development of the world economy “the era of innovations". Studies show that economic and social progress is ensured through an innovative process - the process of producing new knowledge and practices. Thanks to new technologies, deep structural changes are taking place in the economic sectors, new industries are being formed, new jobs are being created. Globalization and the integration of the world economy have further exacerbated competition in the market for high-tech products. In these circumstances, innovative instruments remain the only possible source of increasing the competitiveness of national economies. The innovative way of development of the Russian economy is recognized as the main direction promoting restoration of volumes of production, the international competitiveness, a standard of living of the population, increase of efficiency of national economy, improvement of an ecological condition of a natural environment. Therefore, it is no coincidence that at this stage of development of Russia’s economic system, its main vector is to increase the effectiveness of the implementation of innovation policy. The special attention paid at present to the issues related to the implementation of innovation policy is caused by the active activity of the state, which aims to transfer the Russian economy to the innovative way of development by 2020. It is an undeniable fact that the innovative way of development of the country is the only way to overcome the global socio-economic crises that pose a threat to the sustainable development of the state, both in the present and in the future. This article is devoted to the problems of innovative development of our country.
TRENDS OF DEVELOPMENT OF THE INTERNATIONAL MARKET OF TOURIST SERVICES
Authors: Shpyrnya O. V.
Published: July 2018

This article contains a detailed statistical analysis of the development of the international tourism market. It was considered the period after the end of the Second World War (the starting point, which gave impetus to the rapid development of the industry as a global phenomenon) to the present day. At the same time, the main attention was paid to the last twenty years of the functioning of the tourism and hospitality industry. At the same time, the main attention was paid to the last twenty years of the functioning of the tourism and hospitality industry. In the course of the analysis, various factors that significantly influenced the development of the international market for tourist services were identified: climate change, natural disasters, currency fluctuations, changes in prices for petroleum products, political and military conflicts, terrorism, epidemics of dangerous viral and infectious diseases, financial and economic crises and a number of other factors. It was noted that most of the above factors have a direct impact on the development of the international market of tourist services. However, all these factors are inherently exogenous, that is, they are not directly related to tourism, but have a significant impact on it. The article notes the process of becoming popular tourist destinations, analyzes the trends of modern tourist flows, and studies the patterns of their formation. As a result, the conclusion was made that the presence of the Russian Federation in the international market of tourist services is inadequate, as well as the need to make certain decisions in this area.
SEMANTIC FEATURES OF THE LANGUAGE GAME AND ITS REPRESENTATIONS IN THE PROSE OF A. T. AVERCHENKO
Authors: Kucheryavykh Y. N.
Published: July 2018

The article discusses the features of the formation and functioning of irony as a way of expressing evaluation in the relationship of the characters of works of art A. T. Averchenko. The importance of this phenomenon is determined by the dependence of the elements of its construction, as well as the external historical and literary vertical context, language elements that form the emotional and expressive marking of the statement. Therefore, it is possible to distinguish some types of ironic evaluation: non-reflexive and reflexive. Acting as a means of language comedism, pun in the humorous prose of Arkady Averchenko structurally-semantically organized, and, as an element of the language game, has the laws of construction and selection of stylistic techniques of creation and influence characteristic of the works of the writer. Therefore, the variety of means of creating a comic assessment in the artistic texts of the author suggests that the choice of a particular technique depends on the language personality of the writer, the ratio of linguistic and extralinguistic means of representing the evaluation in the literary text, because the meaning of the phrase predicted by the addressee is created at the expense of the expected word order for the original syntax. Consequently, the realization of the ironic meaning inherent by the Creator of the work of art in the lexemes, becomes clear only from the surrounding context. Since the game is the basis of any culture, the ratio of these concepts becomes the leading person playing, manifested in the manner of speech behavior of the linguistic personality of both the author-Creator and the character - his creations. Therefore, it is appropriate to state that the linguistic personality exists in the space of culture, and, therefore, it can be presented as a linguocultural type as an image recognizable by representatives of a certain national culture, embodied in the character of an artistic work as a creative and playing unique linguistic personality.
8. Sınıf Öğrencilerine Pisagor Bağıntısının Adidaktik Bir Ortamda Öğretimi
Authors: GÜNEŞ Kardelen , Tapan Broutin Menekşe Seden
Published: July 2018

Bu çalışma öğrencilerin didaktik durumlar teorisi ışığında Pisagor Bağıntısını oluştururken, öğretim sürecinde ortaya çıkan didaktik ve adidaktik durumların incelenmesi amaçlamaktadır. Brousseau (1998) tarafından ileri sürülen bir kuram olan Didaktik Durumlar Teorisi tanıtılmaya ve teoride önemli yer tutan adidaktik öğrenme ortamı ana hatlarıyla açıklanmaya çalışılmıştır. Çalışma Sakarya’nın Söğütlü ilçesindeki bir ortaokulun 8. Sınıf öğrencileri olan 27 öğrenci ile 2015-2016 eğitim-öğretim yılı güz döneminde gerçekleştirilmiştir. Ders video ile kayıt altına alınmıştır. Verilerin analizi için betimsel analiz yöntemi kullanılmıştır. Hazırlanan adidaktik ortamda öğrenciler Pisagor Bağıntısı oluşturulmuştur.
Strain gradient elasticity within the symmetric BEM formulation
Authors: Terravecchia S. , Panzeca T. , Polizzotto C.
Published: July 2018

The symmetric Galerkin Boundary Element Method is used to address a class of strain gradient elastic materials featured by a free energy function of the (classical) strain and of its (first) gradient. With respect to the classical elasticity, additional response variables intervene, such as the normal derivative of the displacements on the boundary, and the work-coniugate double tractions. The fundamental solutions - featuring a fourth order partial differential equations (PDEs) system - exhibit singularities which in 2D may be of the order 1/ r 4 . New techniques are developed, which allow the elimination of most of the latter singularities. The present paper has to be intended as a research communication wherein some results, being elaborated within a more general paper [1], are reported.
Development of biodegradable magnesium alloy stents with coating
Authors: Petrini Lorenza , Wu Wei , Gastaldi Dario , Altomare Lina , Farè Silvia , Migliavacca Francesco , Demir Ali Gökhan , Previtali Barbara , Vedani Maurizio
Published: July 2018

Biodegradable stents are attracting the attention of many researchers in biomedical and materials research fields since they can absolve their specific function for the expected period of time and then gradually disappear. This feature allows avoiding the risk of long-term complications such as restenosis or mechanical instability of the device when the vessel grows in size in pediatric patients. Up to now biodegradable stents made of polymers or magnesium alloys have been proposed. However, both the solutions have limitations. The polymers have low mechanical properties, which lead to devices that cannot withstand the natural contraction of the blood vessel: the restenosis appears just after the implant, and can be ascribed to the compliance of the stent. The magnesium alloys have much higher mechanical properties, but they dissolve too fast in the human body. In this work we present some results of an ongoing study aiming to the development of biodegradable stents made of a magnesium alloy that is coated with a polymer having a high corrosion resistance. The mechanical action on the blood vessel is given by the magnesium stent for the desired period, being the stent protected against fast corrosion by the coating. The coating will dissolve in a longer term, thus delaying the exposition of the magnesium stent to the corrosive environment. We dealt with the problem exploiting the potentialities of a combined approach of experimental and computational methods (both standard and ad-hoc developed) for designing magnesium alloy, coating and scaffold geometry from different points of views. Our study required the following steps: i) selection of a Mg alloy suitable for stent production, having sufficient strength and elongation capability; ii) computational optimization of the stent geometry to minimize stress and strain after stent deployment, improve scaffolding ability and corrosion resistance; iii) development of a numerical model for studying stent degradation to support the selection of the best geometry; iv) optimization of the alloy microstructure and production of Mg alloy tubes for stent manufacturing; v) set up, in terms of laser cut and surface finishing, of the procedure to manufacture magnesium stents; vi) selection of a coating able to assure enough corrosion resistance and computational evaluation of the coating adhesion. In the paper the multi-disciplinary approach used to go through the steps above is summarized. The obtained results suggest that developed methodology is effective at designing innovative biomedical devices.
Experimental investigation of fibre reinforced plastics with hybrid layups under high-velocity impact loads
Authors: Romano Marco , Hoinkes Carl J. J. , Ehrlich Ingo , Höcherl Johann , Gebbeken Norbert
Published: July 2018

This paper deals with experimental investigations concerning energy dissipation capacity of different kinds of reinforcement fibres in monolithic and hybrid layups under high-velocity impact loads. The investigated kinds of fibres are carbon, glass and basalt fibres. Therefore test panels, using the same thermoset resin, were built up and cured by autoclave processing. The fibre volume content of the test panels has been determined. Furthermore the influence of a separating layer at selected positions in the hybrid stacked panels was investigated. The results show the influence and the energy dissipation capacity of each single kind of fibre and the enhanced properties for the hybrid layups by hybrid stacking sequences and the use of a separating core material.
A new formulation for estimating maximum stress intensity factor at the mid plane of a SENB specimen: Study based on 3D FEA
Authors: Kudari S. K. , Kodancha K. G.
Published: July 2018

In this investigation, three-dimensional elastic finite element analyses have been conducted to compute the stress intensity factor (KI) in a SENB specimen with varied thickness (B) and crack-length to width ratio (a/W). The results indicate that the magnitude of KI depends on B, and significantly varies along the crackfront from surface to the center of the specimen. The maximum value of KI is found at mid plane of the specimen. Based on the present 3D finite element calculations an effort is made to propose the new analytical relationship between maximum KI and specimen a/W, which helps to estimate maximum KI by only knowing specimen geometry and applied load.
Critical applied stresses for a crack initiation from a sharp V-notch
Authors: Náhlík L. , Huta P. , Štegnerová K.
Published: July 2018

The aim of the paper is to estimate a value of the critical applied stress for a crack initiation from a sharp V-notch tip. The classical approach of the linear elastic fracture mechanics (LELM) was generalized, because the stress singularity exponent differs from 0.5 in the studied case. The value of the stress singularity exponent depends on the V-notch opening angle. The finite element method was used for a determination of stress distribution in the vicinity of the sharp V-notch tip and for the estimation of the generalized stress intensity factor depending on the V-notch opening angle. Critical value of the generalized stress intensity factor was obtained using stability criteria based on the opening stress component averaged over a critical distance d from the V-notch tip and generalized strain energy density factor. Calculated values of the critical applied stresses were compared with experimental data from the literature and applicability of the LEFM concept is discussed.
Cf/C composites: correlation between CVI process parameters and Pyrolytic Carbon microstructure
Authors: Burgio F. , Fabbri P. , Magnani G. , Scafè M. , Pilloni L. , Brentari A. , Brillante A. , Salzillo T.
Published: July 2018

Chemical Vapour Infiltration (CVI) technique has been long used to produce carbon/carbon composites. The Pyrolytic Carbon (Py-C) matrix infiltrated by CVI could have different microstructures, i.e. Rough Laminar (RL), Smooth Laminar (SL) or Isotropic (ISO). These matrix microstructures, characterized by different properties, influence the mechanical behaviour of the obtained composites. Tailoring the process parameters, it is possible to direct the infiltration towards a specific Py-C type. However, the factors, influencing the production of a specific matrix microstructure, are numerous and interconnected, e.g. temperature, pressure, flow rates etc. Due to the complexity of the physical and chemical phenomena involved in CVI process, up to now it has not been possible to obtain a general correlation between CVI process parameters and Py–C microstructure. This study is aimed at investigating the relationship between infiltration temperature and the microstructure of obtained Py-C, for a pilot - sized CVI/CVD reactor. Fixing the other process parameters and varying only the temperature, from 1100°C to 1300°C, the Py-C infiltration was performed on fibrous preforms. Polarized light microscopy, with quantitative measurements of average extinction angle (Ae), and Raman spectroscopy were used to characterize the obtained Py-C microstructures.
The notch effect on fracture of polyurethane materials
Authors: Voiconi T. , Negru R. , Linul E. , Marsavina L. , Filipescu H.
Published: July 2018

This paper investigates the fracture properties and notch effect of PUR materials with four different densities. The asymmetric semi-circular bend specimen was adapted to perform mixed mode fracture toughness tests. This semi-circular specimen with radius R, which contains an edge crack of length a oriented normal to the specimen edge, loaded with a three point bending fixture, was proved to give wide range of mixed modes from pure mode I to pure mode II, only by changing the position of one support. Different types of notched specimens were considered for notch effect investigations and the Theory of Critical Distances was applied. It could be seen that the critical distances are influenced by the cellular structure of investigated materials.
Evaluation of the AZ31 cyclic elastic-plastic behaviour under multiaxial loading conditions
Authors: Anes V. , Reis L. , Freitas M.
Published: July 2018

Components and structures are designed based in their material’s mechanical properties such as Young's modulus or yield stress among others. Often those properties are obtained under monotonic mechanical tests but rarely under cyclic ones. It is assumed that those properties are maintained during the material fatigue life. However, under cyclic loadings, materials tend to change their mechanical properties, which can improve their strength (material hardening) or degrade their mechanical capabilities (material softening) or even a mix of both. This type of material behaviour is the so-called cyclic plasticity that is dependent of several factors such as the load type, load level, and microstructure. This subject is of most importance in design of structures and components against fatigue failures in particular in the case of magnesium alloys. Magnesium alloys due to their hexagonal compact microstructure have only 3 slip planes plus 1 twining plane which results in a peculiar mechanical behaviour under cyclic loading conditions especially under multiaxial loadings. Therefore, it is necessary to have a cyclic elastic-plastic model that allows estimating the material mechanical properties for a certain stress level and loading type. In this paper it is discussed several aspects of the magnesium alloys cyclic properties under uniaxial and multiaxial loading conditions at several stress levels taking into account experimental data. A series of fatigue tests under strain control were performed in hour glass specimens test made of a magnesium alloy, AZ31BF. The strain/stress relation for uniaxial loadings, axial and shear was experimentally obtained and compared with the estimations obtained from the theoretical elastic-plastic models found in the state-of-the-art. Results show that the AZ31BF magnesium alloy has a peculiar mechanical behaviour, which is quite different from the steel one. Moreover, the state of the art cyclic models do not capture in full this peculiar behaviour, especially the cyclic magnesium alloys anisotropy. Further, an analysis is performed to identify the shortcomings inherent to the actual cyclic models in the capture of the magnesium alloys cyclic behaviour. Several conclusions are drawn.
Interlaminar fracture in woven carbon/epoxy laminates
Authors: Reis Paulo N.B. , Ferreira José A.M. , Costa José D.M. , Pereira António M.
Published: July 2018

This paper describes an experimental study developed to characterize the mode I and mode II fracture toughness of carbon/epoxy woven composites, using DCB and ENF tests, respectively. The laminates were manufactured using an epoxy resin and twelve woven balanced bi-directional layers of carbon fibres, all of them with the same orientation (0/90º). Significant instantaneous delaminations were observed particularly for the DCB specimen, which were responsible for an oscillatory behaviour of GI versus crack length. The maximum values obtained for GIC and GIIC were 281 and 1800 J/m2, respectively.
Integrated assessment procedure for determining the fracture strength of glass components in CSP systems
Authors: Guerra Rosa L. , Cruz Fernandes J. , Li B.
Published: July 2018

The structural integrity and reliability of glass components are key issues for concentrated solar power (CSP) systems. For example, the glass windows in a solar furnace may suffer catastrophic fracture due to thermal and structural loadings, including reaction chamber pressure cycling. Predicting design strength provides the basis for which the optical components and mounting assembly can be designed so that failure does not occur over the operational lifetime of a given CSP system. The fracture strength of brittle materials is dependent on the size and distribution of cracks or surface flaws. Due to the inherent brittleness of glass resulting in catastrophic failure, conservative design approaches are currently used for the development of optical components made of glass, which generally neglect the specific glass composition as well as subcritical crack growth, surface area under stress, and nature of the load – either static or cyclic – phenomena. In this paper, several methods to characterize the strength of glass are discussed to aid engineers in predicting a design strength for a given surface finish, glass type, and environment. Based on the Weibull statistical approach and experimental data available on testing silica glass rod specimens, a theoretical model is developed for estimating their fracture strength under typical loading conditions. Then, an integrated assessment procedure for structural glass elements is further developed based on fracture mechanics and the theory of probability, which is based on the probabilistic modelling of the complex behaviour of glass fracture but avoids the complexity for calculation in applications. As an example, the design strength of a glass window suitable for a solar furnace reaction chamber is highlighted.
Time-history simulation of civil architecture earthquake disaster relief- based on the three-dimensional dynamic finite element method
Authors: Bing Liu , Yaoguang Qi , Jiyun Du
Published: July 2018

Earthquake action is the main external factor which influences long-term safe operation of civil construction, especially of the high-rise building. Applying time-history method to simulate earthquake response process of civil construction foundation surrounding rock is an effective method for the anti-knock study of civil buildings. Therefore, this paper develops a civil building earthquake disaster three-dimensional dynamic finite element numerical simulation system. The system adopts the explicit central difference method. Strengthening characteristics of materials under high strain rate and damage characteristics of surrounding rock under the action of cyclic loading are considered. Then, dynamic constitutive model of rock mass suitable for civil building aseismic analysis is put forward. At the same time, through the earthquake disaster of time-history simulation of Shenzhen Children’s Palace, reliability and practicability of system program is verified in the analysis of practical engineering problems.
The influence of fibre orientation on the post-cracking tensile behaviour of steel fibre reinforced self-compacting concrete
Authors: Abrishambaf A. , Cunha V.M.C.F. , Barros J.A.O.
Published: July 2018

Adding fibres to concrete provides several advantages, especially in terms of controlling the crack opening width and propagation after the cracking onset. However, distribution and orientation of the fibres toward the active crack plane are significantly important in order to maximize its benefits. Therefore, in this study, the effect of the fibre distribution and orientation on the post-cracking tensile behaviour of the steel fibre reinforced self-compacting concrete (SFRSCC) specimens is investigated. For this purpose, several cores were extracted from distinct locations of a panel and were subjected to indirect (splitting) and direct tensile tests. The local stress-crack opening relationship (?-w) was obtained by modelling the splitting tensile test under the finite element framework and by performing an Inverse Analysis (IA) procedure. Afterwards the ?-w law obtained from IA is then compared with the one ascertained directly from the uniaxial tensile tests. Finally, the fibre distribution/orientation parameters were determined adopting an image analysis technique.
Development of an engineering methodology for non-linear fracture analysis of impact-damaged pressurized spacecraft structures
Authors: Telichev Igor
Published: July 2018

Motivated by the dramatic worsening and uncertainty of orbital debris situation, the present paper is focused on the structural integrity of the spacecraft pressurized modules/pressure vessels. The objective is to develop an engineering methodology for non-linear fracture analysis of pressure wall damaged by orbital debris impact. This methodology is viewed as a key element in the survivability-driven spacecraft design procedure providing that under no circumstances will the “unzipping” occur. The analysis employs the method of singular integral equation to study the burst conditions of habitable modules, although smaller vessels containing gases at higher pressures can also be analyzed.
Specimen thickness effect on elastic-plastic constraint parameter A
Authors: Nikishkov G.P. , Matvienko Yu.G.
Published: July 2018

Three-dimensional elastic-plastic problems for a power-law hardening material are solved using the finite element method. Distributions of the J-integral and constraint parameter A along the crack front for varying specimen thickness and crack depth are determined for edge cracked plate, center cracked plate, three point bend and compact tension specimens. The constraint parameter A is a measure of stress field deviation from the HRR field. Higher A values signify lower specimen constraint. Results of finite element analyses show that the constraint parameter A significantly decreases when specimen thickness changes from 0.1 to 0.5 of the specimen width. Then it has more or less stable value. Among four specimen the highest constraint is demonstrated by the compact tension specimen which has the constraint parameter A lower than its small scale yielding value.
Experimental evaluation of plasticity-induced crack shielding from crack tip displacements fields
Authors: Vasco-Olmo J.M. , Díaz F.A.
Published: July 2018

In this work it is proposed a methodology for the evaluation of plasticity-induced crack shielding from the analysis of the crack tip displacements fields measured by digital image correlation. This methodology is based on the evaluation of the stress intensity factors determined from the displacements fields measured at the vicinity of the tip of a growing fatigue crack. For the characterisation of the crack tip displacements field, CJP model has been implemented. This model considers the shielding effects due to plasticity generated during fatigue crack growth. For the purpose of the current work, several fatigue experiments at different R-ratios have been conducted on Al2024-T3 compact tension specimens. In addition, compliance based methods have been adopted to perform a comparison of the results with those obtained by DIC. Results show a good level of agreement, illustrating the enormous potential of DIC technique for the study of fracture mechanics problems.