bluuebunny/crossref_metadata_2025 huggingface dataset:
TOPLUMSAL BELLEK, ‘SÜRGÜN’ VE BELGESEL SİNEMA
Authors: BİNGÖL Canel
Published: July 2018

﻿Mevcut dünya algımız geçmiş deneyimlerimizle sıkı
bir bağlantı içindedir ve bellek bugünkü yaşantımızı şekillendirmede etkileyici
bir güçtür. Yaşanmış, yaşanmakta ve yaşanacak olanın anlamlandırılması
önemlidir. Bellek, kimliğin tamamlayıcısıdır. Bellek kavramı ile belgesel
sinema iç içe geçmiş kavramlardır. Bellek bir deneyimin bilinç düzeyine
çıkışını temsil ederken, belgesel sinema bu konuda belleğe yardımcı olmaktadır.
Toplumsal ilişkiler içinde ‘ötekiler’ nedeniyle sürekli yeniden kurulan kimlik,
sinema sanatıyla sürgün/göç olgusu arasında yakından bir bağ da
oluşturmaktadır. Bir metafor ya da bir kavram olarak sürgün figürüne ait
yaşanan ‘kayıp’ daima bir bellek kaybı sorununu 
da içerir. Zaman geçer ve belleğimiz bize, olup bitenler hakkında sadece
belirsiz bir fikir verebilir. Anıların yeniden canlandırılmasıyla, tanıdık
olanla tekinsiz olan arasında yaşanan deneyim, ruhsal olan ile sosyal olan
arasındaki bağı kurmanın olanaklarını sunar. Kuşaklararası
bir aktarım aracı olan bellek ve dolayımlı güncel ritüeli olarak sinemanın
izini sürenler; işte bu yolculukta, sürgünün/yokluğun/kaybın deneyimi ile
karşılaşırlar. Bir ‘düşgücü fabrikası’ olarak sinema ve bellek temalarını ele
alan çeşitli görüşleri Winnicott’yen bir bütünleştiricilik ekseninde ele alan bu
tartışma ve çalışmada; bellek, görsellik ile zaman ve mekandan ‘sürgün’
edilenin belgelenmesi meselesinin temel dinamikleri incelenmiştir.
Uma nova abordagem híbrida para regulação da Educação Superior Privada - promessa ou possibilidade real?
Authors: CORRÊA ENEIDA CARDOSO DE BRITTO
Published: July 2018

O ingresso numa instituição de ensino superior privada brasileira é sempre uma tarefa difícil, complexa, envolve disciplina, persistência e recursos financeiros de alunos e pais para que o objetivo final da conclusão seja alcançado. Neste trabalho, sobre a expansão da Educação Superior Privada no país nos últimos vinte anos, discutimos objetivos, rumos, apresentamos os principais atores públicos e privados e a sua forma de articulação, com destaque para as empresas prestadoras de serviços educacionais – que representam o Mercado – e as instituições do Terceiro Setor – filantrópicas, comunitárias e confessionais. Além de descrever, a pesquisa levantou possibilidades, dilemas e desafios para a regulação da Educação Superior Privada no país, priorizando a discussão sobre uma nova abordagem regulatória, denominada híbrida, integrando: regulação social e regulação econômica; políticas regulatórias e políticas programáticas; ações regulatórias do Ministério da Educação com ações fiscalizatórias e de monitoramento da Receita Federal do Brasil e do Conselho Administrativo de Defesa Econômica; e ações regulatórias com ações de fomento.PALAVRAS-CHAVES: ensino superior privado; regulação híbrida; Mercado e Terceiro Setor.
O SECTOR COOPERATIVO PORTUGUÊS DURANTE PERÍODOS DE CRISE DO SÉC: XX E XXI. UMA VISÃO DESCRITIVA E CRÍTICA DA EVOLUÇÃO DO SECTOR COOPERATIVO EM PERÍODOS DE CRISE
Authors: Santos Dinis Daniel
Published: July 2018

O presente trabalho tem como objetivo lançar um olhar crítico sobre a evolução do número de cooperativas em Portugal durante os períodos-chave da Economia Portuguesa no século XX e XXI. Para isto, foi feita uma breve introdução à economia social e ao setor cooperativo. De seguida são apresentados os períodos-chave, subsequentemente descritos e analisados individualmente quanto ao número de cooperativas existentes. Relativamente ao período de 2007 a 2010, é feita uma análise mais detalhada, não apenas quanto ao número de cooperativas, mas também quanto à área de atuação das mesmas. Conclui-se assim que um crescimento no produto nacional corresponde a um crescimento no número de cooperativas e vice-versa.
A CERTEZA DE SI E O DESCOBRIMENTO DA ESSÊNCIA DO DIREITO: POR UMA PESQUISA JURÍDICA ALÉM DE DESCARTES
Authors: Kosop Roberto José Covaia , Souza-Lima José Edmilson de
Published: July 2018

O presente artigo analisa as contribuições epistemológicas e metodológicas do filósofo e matemático René Descartes (1596 – 1650) ao campo jurídico, culminando na reflexão das limitações do método proposto por tal pensador e da necessidade de complementação da visão jurídica neste tocante. O caminho metodológico utilizado não pretendeu esgotar as obras do autor, ao passo que restringiu-se no “Discurso do Método”, apoiado pelas “Meditações Metafísicas”, para demonstrar como da teoria cartesiana é possível derivar preceitos fundantes do Direito, em especial, a percepção utilitária acerca do conhecimento e a emancipação por intermédio do entendimento do discurso. Desta forma, foi possível concluir que, não obstante o projeto colonizador de conquista do mundo objetivo que limita as fronteiras do campo jurídico, o pensamento de Descartes determinou o núcleo de percepção jurídica tanto epistemológica quanto metodologicamente para apropriação do ambiente físico. PALAVRAS-CHAVE: Metodologia Jurídica; Racionalismo Inato; Método Cartesiano.
GREEN KUBAN IN DAYS OF THE CIVIL WAR IN RUSSIA
Authors: Sivkov S. M.
Published: July 2018

In a review of military memoirs, I. G., Savchenko a brief description of the work, its relevance, reveals the controversial biography of the author of the memoirs, explains the importance of memories to the modern reader. The main events of memories takes place in the Kuban and black sea in 1920. The author of the memoir failed to disclose the difficult contradictions between the peasants of the black sea and Kuban Cossacks. Reveals position of a number of leaders polanskogo movement on relationships with General P. N. Wrangel and the Menshevik Georgia. Indicated the position of the leaders of the Kuban of the Bolsheviks in relation to military experts. Savchenko, in his memoirs touched on this little-known story of the civil war, how the relationship of red and green. Celebrated and complex relationship between the Kuban Rada and the General command of the Armed forces of South Russia. The book is a vivid description of the events of the era of the civil war in the Kuban and black sea coast. The author was able to objectively evaluate the changes that occurred in the camp of the red in three years of Civil war, including those associated with changes in the field of penal policy. However, in General, felt his negative attitude to the new government, the hope for her downfall in the next few years.
THE POSITION OF THE RUSSIAN SCIENTISTS OF SCIENTIFIC INSTITUTIONS DURING THE CIVIL WAR
Authors: Sivkov S. M.
Published: July 2018

Hundred years separates us from the outbreak of Civil war in Russia. This is sufficient time for a rethinking of those past events that shocked the world. The reader is provided a review of the new scientific publication of the Krasnodar researcher A.N. Eremeeva, devoted to problems of development of science and the existence of scholars in this difficult period. Covers a considerable part of the territory of the former Russian Empire, associated with the confrontation of two social systems. Identified problems encountered with the mass relocation of universities and scientific personnel of the country and their daily lives. Given the social structure of the scientific and scientific-pedagogical personnel of higher schools of the prerevolutionary period. “Scientific" survival strategy allows to overcome depressive States, to implement the period of time in extraordinary circumstances, to increase professional competence, to develop optimistic model of the future life. One of the General conclusions indicates that the years of the civil war, a bloody fratricidal slaughter, as paradoxical as it sounds, was an important step in the “intellectualization" of the Russian regions. It is associated not only with civilians, but with the First world war. Materials peer-reviewed monographs can be used by students, graduate students, scientists, all interested in the history of Russian science and the Russian intelligentsia during the Civil war.
THE FORMATION OF THE OPTIMAL CAPITAL STRUCTURE AS THE BASIS FOR FINANCIAL SECURITY CORPORATION
Authors: Sahakyan A.
Published: July 2018

In the economy is a attribute of of the and the state is the of financially corporations are not only to high business to maximize to ensure the of investors, but to ensure the stability of the increase economic One of the of financial and security of the in conditions of is the of import A decisive to play is the with high technical and potential.
HOW TO IMPROVE THE INNOVATIVE CLIMATE OF THE KRASNODAR TERRITORY?
Authors: Zelinskaya M. V. , Vitmayer A. V.
Published: July 2018

The article considers the conditions for the development of science and entrepreneurship in the Krasnodar Territory. The reasons for why the results of research work in most universities and research institutes are being patented are being studied, but they are almost not involved in economic turnover. The objectives of the advisory council of the Krasnodar Territory are listed. The sources of financing of internal expenditures for research and development in the Krasnodar Territory, as well as the main indicators characterizing the state and level of development of the scientific and innovative potential of the region, were also studied. s a result, we found that a significant obstacle to the transition of development from the laboratory to business is the problem of manufacturing prototypes of technical products. Without an operational prototype, it is almost impossible to switch to productive negotiations with an investor, but the developer does not always have his own resources and other resources, including information, which would be sufficient for the production and testing of the prototype. Thus, there is a vicious circle, which at the system level has not yet been broken. We propose that the interaction of science and business includes a power that fulfills the function of an information catalyst. Thus, in order to improve the innovative climate, the classical model of the triple helix “government-business-science".
SOME ASPECTS OF ESTIMATION OF THE STATE OF NATIONAL SECURITY OF THE RUSSIAN FEDERATION
Authors: Bezuglaya N. S.
Published: July 2018

National security depends mostly on the quality of executive and strategic planning of economy. Evaluation of its effectiveness is possible only with national security system of indicators, which are partially listed in the regulatory documents. But the absence of a complete indicators system makes it impossible to conduct a thorough analysis. This is why empirical research of security evaluation criteria is essential. National Security Strategy of Russian Federation and its evaluation criteria is part of a long-term development strategy till 2020. Analysis of main priorities of the Strategy indicates absence of legal norms, which would bind institutions to activities within national security strategy. There is also lack of planning at the domestic level. A number of criteria indicate low level of national interest security. A significant marker of negative social-economical occurrences is ever-increasing fraction of population with a wage below minimum standard of living. Absence of cycle manufacturing of capital funds leads to low labor efficiency and high dependence on high-quality commodities. One of the issues, which is occasionally brought to discussion and is essential to this study, is determination of the degree to which economy of Russian Federation should be closed. But considering the modern manufacturing resources and the level of education of skilled labor the efficiency of closed economy causes doubt. In author’s opinion, strategically important are such aspects of national security as long-term projection of needs and trends of society, science and technology development, formation of employment policies, which aim at adequacy of public needs and specialists’ qualification profiles as well as recovery of reprocessing cyclicity of capital funds.
TRANSPORT PROBLEM: ANALYSIS, PROSPECTS AND PROPOSALS
Authors: Lashko S. I. , Milovanov V. F.
Published: July 2018

The article is devoted to the analysis of possible solutions of traffic jams, which have become an integral part of modern society. Modern transport system has many problems that are both complex and global in nature, and cannot meet sufficiently the needs of the people. The reasons lie in the imperfect organization of traffic, various kinds of miscalculations in the design and construction of roads and transport interchanges. Attempts to solve the problem of traffic jams have been made repeatedly, in different countries of the world, many researchers believe that their solution is enough to build new road junctions and the separation of traffic flows. However, according to the authors, the most acceptable, in particular, for our country, may be the ERP system, which is used in Singapore. This system involves the collection of fare: the more loaded the road, the higher the fee waiting for the traffic participant, and Vice versa, in the case of “empty" road fee will not be charged. This and other systems to cope with the transport problem are analyzed in this article.
Sınıf Öğretmenlerinin Okuma-Yazma Öğretiminde Karşılaşıkları Güçlüklerin Hizmetiçi Eğitim Yoluyla Giderilmesi
Authors: AYDIN Harun , KARTAL Hülya
Published: July 2018

Bu
araştırmanın amacı, sınıf öğretmenlerinin ‘Ses Temelli Cümle Yöntemi’ ile
okuma-yazma öğretiminde karşılaştıkları güçlüklerin belirlenmesi ve bu
güçlüklerin hizmetiçi eğitim yoluyla giderilmesidir. Çalışma, karma desen
araştırmadır. Araştırmada 2 farklı grup ile çalışılmıştır. İlk önce birinci
gruptaki Bursa İli İnegöl İlçesinde 2014-2015 eğitim-öğretim yılında 1. sınıf
okutan ve bir sonraki eğitim-öğretim yılında 1.sınıf okutacak olan farklı
sosyoekonomik düzeydeki 12 merkez ilkokulunda görev yapan 136 öğretmene anket
uygulanmış, bu anketlerden 100’ü değerlendirmeye alınmış ve öğretmenlerin
okuma-yazma öğretiminde karşılaştıkları güçlükler belirlenmiştir. Daha sonra,
34 öğretmene seminer döneminde hizmetiçi eğitim verilmiştir. Son olarak eğitime
katılan 34 sınıf öğretmeninden bir sonraki yıl 1. sınıf düzeyinde derse giren
14 sınıf öğretmenine anket tekrar uygulanmıştır. Böylece aradan geçen sürede
hizmetiçi eğitimin etkisinin kalıcılığı belirlenmiştir. Hizmetiçi eğitim
sonrasında ise eğitimi alan grubun cevaplarındaki doğruluk oranının arttığı
görülmüştür. Anketin tekrar uygulandığı üçüncü grubun cevaplarındaki doğruluk
oranlarının azalması, hizmetiçi eğitimde öğrenilenlerin unutulabileceğini ve
hizmetiçi eğitimin sürekliliğinin bir gereksinim olduğunu göstermiştir.
Fen Bilimleri Öğretmenlerinin Ortaöğretime Geçiş Ortak Sınavları Hakkındaki Görüşleri
Authors: ORMANCI Ümmühan , ÇEPNİ Salih , ÜLGER B. Buğra
Published: July 2018

Ülkemizde eğitim politikalarında gerçekleşen değişim ve gelişime paralel olarak, ortaöğretime geçiş sınavlarında değişiklikler meydana gelmektedir. Bu noktada; süreçten en fazla etkilenenlerden biri olan öğretmenlerin, ortaöğretime geçiş sınavları hakkındaki görüşlerinin alınmasının alan yazın açısından önemli olacağı düşünülmektedir. Çalışmanın amacı, farklı illerde görev yapan fen bilimleri öğretmenlerinin ortaöğretime geçiş sınavları hakkındaki görüşlerinin alınmasıdır. Olgu bilim yönteminin kullanıldığı çalışmaya farklı illerde görev yapan 16 fen bilimleri öğretmeni katılmıştır. Veriler sekiz açık uçlu sorudan oluşan görüş formu ile toplanmıştır. Sorularda ortak sınavların; öğretmenlerin ders işleme sürecine kullandıkları yaklaşımlara, değerlendirme yaklaşımlarına ve öğretim teknolojilerine olan etkileri, konuların zamanında tamamlanma durumları, öğrenciler üzerindeki etkileri ve öğretmenlerin önerilerine odaklanılmıştır. Verilerin analizinde nitel araştırmalarda sıklıkla kullanılan içerik analizi kullanılmıştır. Çalışmadan elde edilen verilere göre; öğretmenler ortaöğretime geçiş ortak sınavları ile birlikte öğretim yaklaşımlarında değişime gittiklerini ifade etmişlerdir. Bu durumun temel nedeni öğretmenlerinde ifade ettiği üzere konuları yetiştirememe düşüncesidir. Çalışmadan elde edilen sonuçlar doğrultusunda önerilerde bulunulmuştur.
Impact of Teaching Cohesive Devices on L2 Students’ Language Accuracy in Written Production
Authors: TAHSİLDAR Mohammad Nasim , YUSOFF Zailin Shah
Published: July 2018

A well-written text is not only grammatical, but also cohesive and coherent. Cohesive devices play the most basic role in cohesion of a text and should be taken into consideration in teaching writing. This paper reports on a study investigating the impact of teaching academic text cohesive devices on L2 students’ language accuracy in written production. The main objective of the study is to find out if teaching cohesive devices would enhance students’ prior knowledge and subsequently result in increased written language accuracy. Based on a pre-post-test research design, 40 students enrolled in English for Academic Purposes course at a university in Malaysia were engaged as participants. A note-taking test was conducted prior to and post intervention. The intervention consisted of lessons on academic text cohesive devices. The data was then analysed and reported using descriptive statistics and paired sample t-test. From the findings, it is clear that there is an increase in the minimum and maximum scores as well as in the mean scores between the pre- and post-test. More importantly, there is evidently a significant improvement in the participants’ post-test language accuracy as evaluated through number of error-free t-units. In sum, the teaching of academic text cohesive devices does have a significant impact on language accuracy in written production. Hence, this study recommends L2 learners’ prior knowledge activation to enhance written language accuracy.
Response of porous SMA: a micromechanical study
Authors: Sepe V. , Marfia S. , Auricchio F.
Published: July 2018

Lately porous shape memory alloys (SMA) have attracted great interest as low weight materials characterized by high energy dissipation capability. In the present contribution a micromechanical study of porous SMA is proposed, introducing the simplifying hypothesis of periodic distribution of voids. The mechanical response of the heterogeneous porous medium is derived by performing nonlinear finite element micromechanical analyses considering a typical repetitive unit cell made of a circular hole in a dense SMA matrix and prescribing suitable periodicity and continuity conditions. The constitutive behavior and the dissipation energy capability of the porous Nitinol are examined for several porosity levels. Numerical applications are performed in order to test the ability of the proposed procedure to well capture the overall behavior and the key features of the special heterogeneous material.
The strong formulation finite element method: stability and accuracy
Authors: Tornabene Francesco , Fantuzzi Nicholas , Bacciocchi Michele
Published: July 2018

The Strong Formulation Finite Element Method (SFEM) is a numerical solution technique for solving arbitrarily shaped structural systems. This method uses a hybrid scheme given by the Differential Quadrature Method (DQM) and the Finite Element Method (FEM). The SFEM takes the best from DQM and FEM giving a highly accurate strong formulation based technique with the adaptability of finite elements. The present study investigates the stability and accuracy of SFEM when applied to 1D and 2D structural components, such as rods, beams, membranes and plates using analytical and semi-analytical well-known solutions. The numerical results show that the present approach can be very accurate using a small number of grid points and elements, when it is compared to standard FEM.
Bond-slip analysis via a cohesive-zone model simulating damage, friction and interlocking
Authors: Serpier R. , Varricchio L. , Sacco E. , Alfano G.
Published: July 2018

A recently proposed cohesive-zone model which effectively combines damage, friction and mechanical interlocking has been revisited and further validated by numerically simulating the pull-out test, from a concrete block, of a ribbed steel bar in the post-yield deformation range. The simulated response is in good agreement with experimental measurements of the bond slip characteristics in the post-yield range of deformed bars reported in the literature. This study highlights the main features of the model: with physically justified and relatively simple arguments, and within the sound framework of thermodynamics with internal variables, the model effectively separates the three main sources of energy dissipation, i.e. loss of adhesion, friction along flat interfaces and mechanical interlocking. This study provides further evidence that the proposed approach allows easier and physically clearer procedures for the determination of the model parameters of such three elementary mechanical behaviours, and makes possible their interpretation and measurement as separate material property, as a viable alternative to lumping these parameters into single values of the fracture energy. In particular, the proposed approach allows to consider a single value of the adhesion energy for modes I and II.
Resilience and ductility of Oxy-fuel HAZ cut
Authors: Martín-Meizoso A. , Aldazabal J. , Pedrejón J.L. , Moreno S.
Published: July 2018

Cutting processes affect the material to a deeper or shallower attached-to-the-cut zone. Its microstructure, its hardness and mechanical properties are changed. Also the cutting process introduces surface roughness and residual stresses. In most cases it is recommended to remove this region by grinding, in order to keep a smoother surface, free from the above mentioned effects. This work presents the characterization results of the Heat Affected Zone (HAZ) of a steel plate of grade S460M, with a thickness of 25 mm, cut by flame oxyfuel gas cutting. The HAZ microstructure is observed (and the depth of the HAZ measured), the hardness profile and the stress vs. strain curves until fracture are measured by testing micro-tensile samples, instrumented with strain gauges. Micro-Tensile specimens are 200 microns in thickness and were obtained from layers of the HAZ at different distances from the oxy-fuel cut. The obtained stress-strain curves are compared with the hardness measurements and the observed metallography.
Improvements in self-consolidating cementitious composites by using micro carbonized aggregates
Authors: Ferro Giuseppe Andrea , Ahmad Sajjad , Khushnood Rao Arsalan , Restuccia Luciana , Tulliani Jean Marc
Published: July 2018

There is growing interest in the use of self-consolidating cementitious systems in construction industry. The present research was conducted to enhance the mechanical performance of cement composites by the utilization of micro-sized inert particles. This paper deals with the synthesis of micro-sized inert carbonized particles from hemp hurds. The synthesized carbonized particles were characterized by field emission scanning electron microscope (FESEM). These particles were further used as additive in self-consolidating cement composites. Total of four different wt% additions (i.e. 0.08, 0.20, 1.00 and 3.00 by wt% of cement) were investigated. The cement composites containing carbonized particles inclusions were characterized by three point bending and compression tests. The results indicate that the carbonized particles additions enhanced the flexural and compressive strengths of the cement composites. It was also observed that the fracture properties and the energy absorption capability of the cement composites were enhanced substantially.
SCC and Corrosion Fatigue characterization of a Ti-6Al-4V alloy in a corrosive environment – experiments and numerical models
Authors: Baragetti S. , Villa F.
Published: July 2018

In the present article, a review of the complete characterization in different aggressive media of a Ti-6Al-4V titanium alloy, performed by the Structural Mechanics Laboratory of the University of Bergamo, is presented. The light alloy has been investigated in terms of corrosion fatigue, by axial fatigue testing (R = 0.1) of smooth and notched flat dogbone specimens in laboratory air, 3.5% wt. NaCl–water mixture and methanol–water mixture at different concentrations. The first corrosive medium reproduced a marine environment, while the latter was used as a reference aggressive environment. Results showed that a certain corrosion fatigue resistance is found in a salt water medium, while the methanol environment caused a significant drop – from 23% to 55% in terms of limiting stress reduction – of the fatigue resistance of the Ti-6Al-4V alloy, even for a solution containing 5% of methanol. A Stress Corrosion Cracking (SCC) experimental campaign at different methanol concentrations has been conducted over slightly notched dog-bone specimens (Kt = 1.18), to characterize the corrosion resistance of the alloy under quasi-static load conditions. Finally, crack propagation models have been implemented to predict the crack propagation rates for smooth specimens, by using Paris, Walker and Kato-Deng-Inoue-Takatsu propagation formulae. The different outcomes from the forecasting numerical models were compared with experimental results, proposing modeling procedures for the numerical simulation of fatigue behavior of a Ti-6Al-4V alloy.
Design optimization of cruciform specimens for biaxial fatigue loading
Authors: Baptista R. , Claudio R. A. , Reis L. , Guelho I. , Freitas M. , Madeira J. F. A.
Published: July 2018

In order to correctly assess the biaxial fatigue material properties one must experimentally test different load conditions and stress levels. With the rise of new in-plane biaxial fatigue testing machines, using smaller and more efficient electrical motors, instead of the conventional hydraulic machines, it is necessary to reduce the specimen size and to ensure that the specimen geometry is appropriated for the load capacity installed. At the present time there are no standard specimen’s geometries and the indications on literature how to design an efficient test specimen are insufficient. The main goal of this paper is to present the methodology on how to obtain an optimal cruciform specimen geometry, with thickness reduction in the gauge area, appropriated for fatigue crack initiation, as a function of the base material sheet thickness used to build the specimen. The geometry is optimized for maximum stress using several parameters, ensuring that in the gauge area the stress is uniform and maximum with two limit phase shift loading conditions. Therefore the fatigue damage will always initiate on the center of the specimen, avoiding failure outside this region. Using the Renard Series of preferred numbers for the base material sheet thickness as a reference, the reaming geometry parameters are optimized using a derivative-free methodology, called direct multi search (DMS) method. The final optimal geometry as a function of the base material sheet thickness is proposed, as a guide line for cruciform specimens design, and as a possible contribution for a future standard on in-plane biaxial fatigue tests.
Double peeling of elastic pre-tensioned tapes
Authors: Putignano C. , Afferrante L. , Carbone G. , Demelio G.
Published: July 2018

Peeling is a physical mechanics involved in the detachment of many natural and industrial applications. In this paper, we investigate the double peeling of an endless elastic pre-stressed tape adhering to a flat smooth rigid substrate. Solutions are given in closed form and their stability is discussed. Critical pull-off force needed to detachment is shown to be higher for pre-stressed tapes. However, when a pre-stress is high, tapes behave differently and may spontaneously detach from the rigid substrate.
Mechanical behavior of a sandwich with corrugated GRP core: numerical modeling and experimental validation
Authors: Tumino D. , Ingrassia T. , Nigrelli V. , Pitarresi G. , Urso Miano V.
Published: July 2018

In this work the mechanical behaviour of a core reinforced composite sandwich structure is studied. The sandwich employs a Glass Reinforced Polymer (GRP) orthotropic material for both the two external skins and the inner core web. In particular, the core is designed in order to cooperate with the GRP skins in membrane and flexural properties by means of the addition of a corrugated laminate into the foam core. An analytical model has been developed to replace a unit cell of this structure with an orthotropic equivalent thick plate that reproduces the in plane and out of plane behaviour of the original geometry. Different validation procedures have been implemented to verify the quality of the proposed method. At first a comparison has been performed between the analytical model and the original unit cell modelled with a Finite Element mesh. Elementary loading conditions are reproduced and results are compared. Once the reliability of the analytical model was assessed, this homogenised model was implemented within the formulation of a shell finite element. The goal of this step is to simplify the FE analysis of complex structures made of corrugated core sandwiches; in fact, by using the homogenised element, the global response of a real structure can be investigated only with the discretization of its mid-surface. Advantages are mainly in terms of time to solution saving and CAD modelling simplification. Last step is then the comparison between this FE model and experiments made on sandwich beams and panels whose skins and corrugated cores are made of orthotropic cross-ply GRP laminates. Good agreement between experimental and numerical results confirms the validity of the proposed model.
The effect of steady torsion on fatigue crack growth under rotating bending loading on aluminium alloy 7075-T6
Authors: da Fonte M. , Reis L. , de Freitas M.
Published: July 2018

Axles and shafts are of prime importance concerning safety in the transportation industry and railway in particular. Design rules for axles and shafts are mainly based on endurance curves for the material used according to the established standards and procedures. Recently, the knowledge of fatigue crack growth under typical loading conditions of axles and shafts with rotating bending and steady torsion is being object of research and industrial studies in order to apply damage tolerance concepts, mainly for maintenance purposes. The effect of a steady torsion on fatigue crack growth under rotating bending is focused in this paper. While axles and shafts in the transportation industry are traditionally designed on steels, the need for weight reduction due to fuel economy and eco-design constraints, lightweight materials must be considered for these applications. In this study, fatigue crack growth on rotating bending axles and shafts with or without an applied steady torsion is presented. Fracture mechanics approaches are used to analyze the results based on Stress Intensity Factors developed for bending and torsion in shafts and show fatigue crack growth retardation when steady torsion is applied. Fractographic observations using SEM are presented and helped to explain the fatigue crack growth retardation observed when steady torsion is applied to rotating bending. Results are compared for the same loading conditions on steels and relevant differences on fatigue crack growth are commented.
Numerical modelling of reinforced concrete beams with fracture-plastic material
Authors: Sucharda O. , Brozovsky J.
Published: July 2018

This paper describes the use of models of fracture-plastic materials for reinforced concrete in numerical modelling of beams made from reinforced concrete. The purpose of the paper is to use of a model of concrete for modelling of a behaviour of reinforced concrete beams which have been tested at the University of Toronto within re-examination of classic concrete beam tests. The original tests were performed by Bresler- Scordelis. A stochastic modelling based on LHS (Latin Hypercube Sampling) has been performed for the reinforced concrete beam. An objective of the modelling is to evaluate the total bearing capacity of the reinforced concrete beams depending on distribution of input data. The beams from the studied set have longitudinal reinforcement only. The beams do not have any shear reinforcement. The software used for the fracture-plastic model of the reinforced concrete is the ATENA.
Impact response of balsa core sandwiches
Authors: Mortas Nurdane , N.B. Reis Paulo , A.M. Ferreira José
Published: July 2018

The benefits of resins nano-enhanced on the impact response of sandwich composites made by fiber glass/epoxy skins and balsa wood core were studied. Afterwards, the influence of the core's discontinuity was analyzed in terms of impact strength. For better dispersion and interface adhesion matrix/clay nanoclays were previously subjected to a silane treatment appropriate to the epoxy resin. Resins enhanced by nanoclays promote higher maximum impact loads, lower displacements and the best performance in terms of elastic recuperation. The core's discontinuity decreases the impact strength, but the resin enhanced by nanoclays promotes significant benefits.
Investigation about crack propagation paths in thin rim gears
Authors: Curà F. , Mura A. , Rosso C.
Published: July 2018

Crack propagation in gears is a problem related not only to the life of the components, but also to the concept of failsafe design. Fail safe design means to design a component in order that, if a failure occurs, this may cause a “safe failure”. This aspect is very important above all in aerospace industry. As a matter of fact, in aerospace application, the need of reducing weight brings to produce gears with very thick rim and web. Considering thin rim gears, when a crack is nucleated near the tooth root, it may propagate through the tooth (causing the loss of the entire tooth or a portion of it) or the propagation may follow a path across the wheel diameter (causing the projection of big parts of the gear that may break the gearbox and may cause serious damage to the aircraft). The first failure mode is define as “failsafe failure” and the second one as “catastrophic failure” and of course has to be avoided. Designers need to have robust design criteria in order to predict crack propagation paths and to avoid catastrophic failures. In literature, few works are present concerning this topic, in particular related to the effect of geometrical parameters that may affect the crack propagation. In this work a numerical analysis about crack propagation in gears with respect to the backup ratio (ratio between tooth height and rim thickness), initial crack position and shape has been done by means of the Extended FEM (XFEM) technique, realizing 3D models. XFEM 3D is a relatively new technique consisting in enriching traditional finite elements with more complex shape functions; in this way it is possible to propagate crack also between mesh nodes and to have mesh independent results. Aim of this paper is to highlight the crack propagation path in order to give to designers an high confident design criterion, related to the gear geometry. In particular, the effect of both rim thickness and orientation of the initial crack have been considered in order to enrich the literature knowledge. Numerical results obtained in this work have been compared with those found in the literature, showing a very good correlation.
A research on detecting and recognizing bridge cracks in complex underwater conditions
Authors: Tao Wang , Tao Du , Xiaohong Zou , Yiming Sun
Published: July 2018

The method aims to recognize and extract the characteristic parameters of bridge cracks based on images of the cracks obtained through the application of preprocessing technologies, such as graying, graphical enhancements, spatial filtering, gray-level threshold segmentation, etc.. The approach has been tested for accuracy to avoid the incorrect identification of chaff as a method error. The proposed method has proved to be rather accurate and effective in extracting information on cracks from the bridge image tests.
An analysis research of the stiffness characteristics of hospital building materials
Authors: Yunyu Chen
Published: July 2018

This paper primarily aims to introduce different stiffness ratio requirements for hospital buildings of various structural styles, to achieve a new standard. The requirements of each stiffness ratio are analyzed, according to the specification formulas and illustrations. And whether the structural deformation situation complies with the code requirement or dissatisfies the specification requests can be intuitively reflected through the application of the chart form, respectively. The corresponding measures complying with the code requirement and the matters needing attention in the schematic design phase are proposed. The comparison analysis for the lateral rigidity and lateral stiffness ratios is performed by applying different methods for the project cases of shear wall, frame tube and partial frame shear wall structures. The proposed computing method may better reflect the stiffness characteristics of the component’s cross-section, with regard to vertical layer, storey height and materials, as well as the actual situation of the turning constraint on both ends. The result thus determined can better reflect the real lateral rigidity of the construction, which is available as a benchmark for engineers designing hospital building structures.
Advanced techniques for estimation of the tensile fracture toughness of adhesive joints
Authors: Campilho R.D.S.G. , Banea M.D. , da Silva L.F.M.
Published: July 2018

Adhesive bonding has become more efficient in the last few decades due to the adhesives developments, granting higher strength and ductility. As a result, adhesives are being increasingly used in industries such as the automotive, aerospace and construction. Thus, it is highly important to predict the strength of bonded joints to assess the feasibility of joining during the fabrication process of components (e.g. due to complex geometries) or for repairing purposes. When using the Finite Element Method with advanced propagation laws, the tensile (Gnc) and shear (Gsc) fracture toughness of adhesive joints must be determined with accuracy. Several conventional methods to obtain Gnc and Gsc exist in the literature, mainly based on Linear Elastic Fracture Mechanics (LEFM). The J-integral technique is accurate to measure these parameters for adhesives with high ductility. In this work, the J-integral is used to obtain Gnc by the Double-Cantilever Beam (DCB) test. An optical measurement method is developed for the evaluation of the crack tip opening and adherends rotation at the crack tip during the test, supported by a Matlab® sub-routine for the automated extraction of these quantities. As output of this work, an optical method that allows an easier and quicker extraction of the parameters to obtain Gnc than the available methods is proposed (by the J-integral technique) and some results are presented regarding joints with different geometry and adherend material.
Numerical simulation of galvanized rebars pullout
Authors: Pereira H.F.S.G. , Cunha V.M.C.F. , Sena-Cruz J.
Published: July 2018

The usage of rebars in construction is the most common method for reinforcing plain concrete and thus bridging the tensile stresses along the concrete crack surfaces. Usually design codes for modelling the bond behaviour of rebars and concrete suggest a local bond stress – slip relationship that comprises distinct reinforcement mechanisms, such as adhesion, friction and mechanical anchorage. In this work, numerical simulations of pullout tests were performed using the finite element method framework. The interaction between rebar and concrete was modelled using cohesive elements. Distinct local bond laws were used and compared with ones proposed by the Model Code 2010. Finally an attempt was made to model the geometry of the rebar ribs in conjunction with a material damaged plasticity model for concrete.
Inter-laminar shear stress in hybrid CFRP/austenitic steel
Authors: Lopes J. , Freitas M. , Stefaniak D. , Camanho P.P.
Published: July 2018

Bolted joints are the most common solution for joining composite components in aerospace structures. Critical structures such as wing to fuselage joints, or flight control surface fittings use bolted joining techniques. Recent research concluded that higher bearing strengths in composite bolted joints can be achieved by a CFRP/ Titanium hybrid lay-up in the vicinity of the bolted joint. The high costs of titanium motivate a similar research with the more cost competitive austenitic steel. An experimental program was performed in order to compare the apparent inter-laminar shear stress (ILSS) of a CFRP reference beam with the ILSS of hybrid CFRP/Steel beams utilizing different surface treatments in the metallic ply. The apparent ILSS was determined by short beam test, a three-point bending test. Finite element models using cohesive elements in the CFRP/Steel interface were built to simulate the short beam test in the reference beam and in the highest interlaminar shear stress hybrid beam. The main parameters for a FEM simulation of inter laminar shear are the cohesive elements damage model and appropriate value for the critical energy release rate. The results show that hybrid CFRP/Steel have a maximum ILSS very similar to the ILSS of the reference beam. Hybrid CFRP/Steel is a competitive solution when compared with the reference beam ILSS. FEM models were able to predict the maximum ILSS in each type of beam.
Influence of crack offset distance on the interaction of multiple cracks on the same side in a rectangular plate
Authors: Bisht Neeraj , Gope P. C. , Panwar Kuldeep
Published: July 2018

In the present work finite element method has been employed to study the interaction of multiple cracks in a finite rectangular plate of unit thickness with cracks on the same side under uniaxial loading conditions. The variation of the stress intensity factor and stress distribution around the crack tip with crack offset distance has been studied. Due to the presence of a neighbouring crack, two types of interactions viz. intensification and shielding effect have been observed. The interaction between the cracks is seen to be dependent on the crack offset distance. It is seen that the presence of a neighbouring crack results in the appearance of mode II stress intensity factor which was otherwise absent for a single edge crack. It can be said that the proximity of cracks is non-desirable for structural integrity. The von-Mises stress for different crack orientations has been computed. Linear elastic analysis of state of stress around the crack tip has also been done.
Measurement and analysis of fatigue crack deformation on the macro- and micro-scale
Authors: Nowell D. , O’Connor S.J. , Dragnevski K.I.
Published: July 2018

The paper describes an experiment which performs in-situ loading of a small compact tension specimen in a scanning electron microscope. Images are collected throughout a number of successive loadincg cycles. These are then analysed using digital image correlation (DIC) in order to produce crack flank displacements as a function of load. This data is then compared with a simple elastic approach, and it is concluded that elastic-plastic analysis is required in order to accurately capture the displacements close to the crack tip. A simple approach due to Pommier and Hamam is therefore employed. This gives a better representation of the data, but predicts a variation of crack tip displacement, ?, which is difficult to explain from a physical perspective. The need for a more sophisticated analysis of the data is therefore highlighted.
Three-dimensional effects on cracked components under anti-plane loading
Authors: Berto F. , Campagnolo A.
Published: July 2018

The existence of three-dimensional effects at cracks has been known for many years, but understanding has been limited, and for some situations still is. Understanding improved when the existence of corner point singularities and their implications became known. Increasingly powerful computers made it possible to investigate three-dimensional effects numerically in detail. Despite increased understanding, threedimensional effects are sometimes ignored in situations where they may be important. The purpose of the present investigation is to study by means of accurate 3D finite element (FE) models a coupled fracture mode generated by anti-plane loading of a straight through-the-thickness crack in linear elastic plates. An extended version of the present work has recently been published in the literature. The results obtained from the highly accurate finite element analyses have improved understanding of the behaviour of through cracked components under anti-plane loading. The influence of plate bending is increasingly important as the thickness decreases. It appears that a new field parameter, probably a singularity, is needed to describe the stresses at the free surfaces. Discussion on whether KIII tends to zero or infinity as a corner point is approached is futile because KIII is meaningless at a corner point. The intensity of the local stress and strain state through the thickness of the cracked components has been evaluated by using the strain energy density (SED) averaged over a control volume embracing the crack tip. The SED has been considered as a parameter able to control fracture in some previous contributions and can easily take into account also coupled three-dimensional effects. Calculation of the SED shows that the position of the maximum SED is independent of plate thickness. Both for thin plates and for thick ones the maximum SED is close to the lateral surface, where the maximum intensity of the coupled mode II takes place.
Estimation of the crack propagation direction in a mixed-mode geometry via multi-parameter fracture criteria
Authors: Malíková L. , Veselý V. , Seitl S.
Published: July 2018

The presented work introduces a numerical parametric study on the crack propagation direction under mixed-mode conditions (mode I + II). It is conducted for the geometry of an eccentric asymmetric fourpoint bending of a single edge notched beam specimen; various levels of mode-mixity are ensured by modifications in the crack length and crack eccentricity. The direction of crack propagation is estimated semianalytically using both the maximum tangential stress criterion and the strain energy density criterion (implemented as a procedure within the used finite element computational code) as well as numerically (from verification reasons). Multi-parameter fracture mechanics is employed in the presented work for precise analytical evaluation of the stress field in the cracked specimen. This theory is based on description of the stress and deformation fields in the cracked body by means of their approximation using several initial terms of the Williams power series. Recent studies show that utilization of only first term of the series, which corresponds to the stress intensity factor (SIF), the single controlling parameter for the crack initiation and propagation assessment in brittle materials, is insufficient in many crack problems. It appears also in this study that the higher-order terms of the asymptotic crack-tip field are of great relevance for the conducted analysis, similarly to a number of other fracture phenomena (near-crack-tip stress field approximation, non-linear zone extent estimation, etc.).
Fretting in complete contacts - the use of Williams’ solution
Authors: Hills D. A. , Flicek R.
Published: July 2018

Williams’ solution may be used to characterize the corners of ‘complete’ fretting contacts. Here we look at the practicalities of conducting fretting tests using a range of different kinds of apparatus and the kind of results they can reveal of practical relevance to establishing a fretting database.