bluuebunny/crossref_metadata_2025 huggingface dataset:
PERANAN BUDAYA ORGANISASI TERHADAP KUALITAS PENDIDIKAN
Authors: Fajriyah Siti Lailatul
Published: July 2018

Penelitian ini ditujukan untuk mengubah peranan budaya kualitas terhadap organisasi pendidikan, dan komitmen organisasional dan menguji pengaruh budaya organisasi, Budaya organisasi didefinisikan sebagai nilai-nilai, kepercayaan dan prinsip-prinsip yang berfungsi sebagai dasar system manajemen organisasi, praktek-praktek manajemen dan perilaku yang membantu memperkuat prinsip prinsip dasar tersebut (Denison,2000). Menurut Peter F Drucker dalamTika (2009) berpendapat bahwa budaya organisasi adalah pokok penyelesaian masalah-masalah eksternal dan internal yang dalam pelaksanaannya di lakukan secara konsisten oleh suatu kelompok yang kemudian di wariskan kepada anggota-anggota baru berbagai cara sebagai cara yang tepat untuk memahami, memikirkan dan merasakan terhadap masalah masalah terkait. Organisasi harus dapat mengatur dan memanfaatkan sedemikian rupa sehingga potensi sumber daya manusia yang ada di organisasi dapat dikembangkan. Pengaturan atau pengelolaan tersebut dimulai dari pengembangan pengintegrasian hingga pengaturan berkaitan dengan penggalian dan pelaksanaan budaya kerja dalam setiap fungsi dan jabatan yang ada di dalam perusahaan. Pengaturan juga berkait pemenuhan kebutuhan manusia (pemberian kompensasi) secara terus menerus dapat menghasilan peningkatan kepuasan kerja. Dari peningkatan kepusan kerja pada akhirnya menghasilkan kinerja yang baik. Namun bila karyawan dalam suatu perusahaan tidak mendapatkan pengaturan yang baik maka berpengaruh terhadap kepuasan, sehingga akibat tidak puasan maka mereka cenderung berperilaku negatif action dalam kerja seperti aksi demonstrasi, aksi mogok, dan aksi mangkir kerja dan sebagainya.
Thermal performance of fish is explained by an interplay between physiology, behaviour, and ecology
Authors: Neubauer Philipp , Andersen Ken H.
Published: July 2018

Increasing temperatures under climate change are thought to affect individual physiology of fish and other ectotherms through increases in metabolic demands, leading to changes in species performance with concomitant effects on species ecology. Although intuitively appealing, the driving mechanism behind thermal performance is contested: thermal performance (e.g., growth) appears correlated with metabolic scope (i.e., oxygen availability for activity) for a number of species, but a substantial number of datasets do not support oxygen limitation of long-term performance. Whether or not oxygen limitations via the metabolic scope, or a lack thereof, have major ecological consequences remains a highly contested question. Here, we propose a general size and trait-based model of energy and oxygen budgets to determine the relative influence of metabolic rates, oxygen limitation, and environmental conditions on ecotherm performance. We show that oxygen limitation is not necessary to explain performance variation with temperature. Oxygen can drastically limit performance and fitness, especially at temperature extremes, but changes in thermal performance are primarily driven by the interplay between changing metabolic rates and species ecology. Furthermore, our model reveals that fitness trends with temperature can oppose trends in growth, suggesting a potential explanation for the paradox that species often occur at lower temperatures than their growth-optimum. Our model provides a mechanistic underpinning that can provide general and realistic predictions about temperature impacts on the performance of fish and other ectotherms, and function as a null model for contrasting temperature impacts on species with different metabolic and ecological traits.
A RELATIVIDADE CONTEMPORÂNEA DO EXERCÍCO INTERNO DA SOBERANIA
Authors: Lima Mario Jorge P de C
Published: July 2018

O processo de globalização iniciado no século 20 tem realizado inúmeras alterações nos comportamentos sociais, entre estes, a redução do protagonismo solitário dos Estados na condução das sociedades, hoje partilhado com a atuação de atores não governamentais. O efeito do surgimento de fenômenos como a globalização e a participação de novos atores conduz a perceber o fim do exercício absoluto da soberania pelo estado, que passa a operar suas prerrogativas de modo relativo. Essa relatividade se verifica sobretudo na constatação de limites ao exercício externo da soberania pelos estados na comunidade internacional. No entanto, a causa da relatividade do exercício da soberania dos estados decorre dos efeitos dos fenômenos contemporâneos sobre o exercício da soberania no âmbito interno, ao interferir e limitar o conteúdo e funções essenciais da concepção pioneira da soberania como poder absoluto.
Identifikasi Divisi Pteridophyta di Kawasan Danau Aur Kabupaten Musi Rawas
Authors: Riastuti Reny Dwi , Sepriyaningsih Sepriyaningsih , Ernawati Devi
Published: July 2018

This study aims to identify the Pteridophyta Division in the Lake Aur Area of ​​Musi Rawas Regency. The research method used is descriptive qualitative. This research was made in 3 plots with size 10 m x 10 m. Based on the result of identification research of Pteridophyta division in Aur Aurland area there are 5 orders, 9 families, 12 genus and 19 species Pteris biaurita, Ploecnemia irregular, Diplazium esculentum, Asplenium nidus, Gleichenia linearis, Christella dentata, Stenochlaena palastris, Diplazium esculentum, Davallia denticulata, Gleichenia linearis, Lygodium scandens, Lygodium circinatum, Nephrolepis exaltata, Nephrolepis cordifoli, Nephrolepis biserrata, Phymatosorus scolopendria, Selaginella wildenowii , Selaginella caudata and Selaginella plana with soil temperature in Aur Aur Area Musi Rawas Regency ranges 27,5˚C-31,5˚C with degree of acidity (pH) of land ranged from 5,11-6,18.

Keywords: pteridophya division, aur lake.
Pengaruh Minat dan Penggunaan Metode terhadap Hasil Belajar IPA Biologi Siswa Kelas VII SMP Negeri 2 Jayapura
Authors: Nesi Mikael , Akobiarek Maik
Published: July 2018

This study aims to determine (1) The influence of interest on student learning outcomes in Biology science lessons in SMP Negeri 2 Jayapura, (2) The influence of the use of methods and interests on student learning outcomes in the science of Biology in SMP Negeri 2 Jayapura, (3) interaction between method and interest toward student learning outcomes in science biology lesson in SMP Negeri 2 Jayapura. This research type is experiment. This research took place from February to May 2017. The population of this study is all students of class VII in SMP Negeri 2 Jayapura. The sample of this research is all students of class VIIJ, VIIK, and VIIL which is divided into 4 classes. Data analysis uses prerequisite test with parametric analysis path with normality test, homogeneity test, and interest question variable data. While hypothesis testing using ANAVA two way. The results showed (1) There is an influence of interest that arise from within the students to the learning outcomes achieved in the learning process with the results of the calculation of high interest variable average 74.87 and the low interest variable average 65.04. (2) There is an average influence of Biology Science learning outcomes in students who are taught using Student Worksheet (LKS) Word Square Model from the students who taught using lecture method on students who have high interest result Fcount = 2.967 more than Ftable = 2.46. (3) There is an average influence of Biology Science learning outcomes in students who are taught using Student Worksheet (LKS) Word Square Model from the students taught using lecture method on students who have low interest result Fcount = 2.952 more than Ftable = 2.46. (4) There is a very significant influence between the learning method and the interest or the influence of the method on the learning outcomes of Biology IPA depending on the student's interest result Fcount = 3.776 more than Ftable = 2.46.

Keywords: word square, interests, learning outcomes
SYSTEM ASPECTS OF INTERACTION OF SPATIAL STRUCTURES OF THE CITY
Authors: Basenko V. P. , Dianova V. A.
Published: July 2018

Ctivities of all managing directors, irrespective of where they are busy: in commercial enterprise, government, municipal department or university, takes place in fixed interaction with the external environment. In spite of the fact that managing directors only in insignificant degree can influence the external environment (or isn’t able to do it at all), they can’t ignore it, are obliged to react to it adequately. Undoubtedly, managing directors can react when changes in the surrounding external environment are already obvious, but it is much better to expect these changes. For simplification of identification of the sectors of the external environment exerting a certain impact on all types of the entities we classify them as economic, technological, social, political and ethical. Of course, this classification mild. Buyers are the most important factor in the economic activity of commercial enterprises turned outside. Without consumers the business company can’t simply exist. For successful performance the entity shall in every possible way aim to learn that people want and are ready to purchase. Business activity of the entity was always determined by the relative level of its technologies. If the commercial enterprise isn’t aware of the last technological achievements which can be used as in a production process of goods and the provided services, and for enhancement of methods of work, then it in a considerable measure is doomed to failure, especially in the conditions of a fierce competition.
ECONOMIC MECHANISM OF SURVIVAL OF THE MINING INDUSTRY OF SOUTHERN RUSSIA
Authors: Shelkunova T. G. , Shulgaty L. P. , Razorenov Y. I.
Published: July 2018

Article is devoted to the problems of a mountain industry of the South of Russia caused by a general crisis of the reformed economy. The directions of survival of the entities are sounded: involvement in the sphere of production of inventories of technogenic fields and enhancement of work of an economic mechanism in market economy. Features of a resource situation and an economic mechanism of mining and processing enterprises are characterized. The criterion of quality of mineral raw materials in the form of onboard content is formulated. The method of the multidimensional comparative analysis for complex assessment of variable technical and economic indicators of activities of the entity is offered. The role of categories flexibility and adaptability as conditions of efficiency of an economic system is opened. As the general direction the concept of decrease in capital and operating costs of the entity by a combination of traditional and conversion technologies in case of the single scheme of development of fields is offered. The characteristic of assessment of parameters of innovative development a method of production functions is this in case of conversion of the entity on innovative technologies. For mathematical handling of experimental results the approximated production function of Kobba-Douglas is recommended. It is offered to estimate a lost profit on the lost value of a useful component determined by the ceiling price of an industry that allows to come to single criterion -profit taking into account damage on losses of mineral in case of alternative technologies.
STATE REGULATION OF THE CONSTRUCTION INDUSTRY
Authors: Hashaeva O. S.
Published: July 2018

Condition of the building complex has an impact on the ability to work all areas of the economy and life processes of reproduction. Currently, construction management in the Russian Federation is considered as self-regulatory control system in this activity with obligatory direct impact of this activity on the part of government. State intervention in the regulation of construction activities necessary to combine state (public) and private interests, with a view to the development of large proportions (ratios) in the economy between consumption, saving and investment on the basis of forecasting, strategic planning, budget financing, taxation and other measures of state influence on investment markets, contracting, real estate The article discusses the role and value of bodies of state regulation of the construction industry, as well as their basic control and monitoring functions. The most important role in the implementation of state influence on the construction industry assigned to the federal bodies of executive power at the regional level identified sectoral authorities and the public sphere of regulation of construction and housing and communal services, at the municipal level describes the functions of the administrative-territorial units in the field. The article also identifies key federal agencies with the greatest impact on the construction industry.
PARTICULARITY OF POLITYCAL LANGUAGE IN THE PEOPLE’S REPUBLIC OF CHINA
Authors: Pak E. M.
Published: July 2018

The article considers the concepts as “metaphor”, “political linguistics”, “a political discourse”, “Confucianism”. The issue of the use of a metaphor in the speech of political figures and what role it plays in political life of the country is touched. The article has examples what turns of speech are used in the speech by political leaders are given favorably to influence and influence public. Influence of Confucianism on consciousness of people and on political life of the country is considered. The relevance of this work lies in fact that use of a metaphor in political language is the direct tool of impact on consciousness of the people and also in how cultural, traditional values of China influence outlook of the person. The aim of this work is to reveal the main postulates of Confucianism and their influence on political consciousness of people. The objective of this article: to give definition of a metaphor; to reveal her main functions in a political discourse; to learn how traditional cultural values influence change of people’s consciousness according to example of Confucian philosophy; what role in domestic and foreign policy is played by the concepts connected with centuries-old history and the culture of China.
INVESTMENT ATTRACTIVENESS OF THE ENTERPRISE AS A FACTOR OF EFFECTIVE DEVELOPMENT
Authors: Oganesan L. L. , Basenko V. P.
Published: July 2018

The article investigates the process of investment, which plays an important role in the economy of any country, region, enterprise. Investing largely determines the economic growth of the region in particular, employment of the population and is a significant element base, on which to base the economic development of society. Modern management practices by business entities in different regions of the country often has significant differences. In the conditions of post-crisis state of the economy is greatly influenced by the rational and efficient use of capital, which requires scientific substantiation and improvement of the financial management or governance mechanism the movement of financial resources, directed on increase of investment growth and profit. Investing is one of the most important aspects of any dynamically developing organization (enterprise), which gives priority to profitability.
IMPROVEMENT OF LEGAL REGULATION OF INCLUSIVE EDUCATION IN THE HIGHER EDUCATION SYSTEM IN KRASNODAR REGION
Authors: Belgisova K. V. , Simatova E. L. , Shapoval O. V.
Published: July 2018

In the current Russian legislation stipulates that for the organization of inclusive education in the Universities need to create special conditions, without which it is impossible or hampered the development of the educational programs of students with disabilities. In economically successful regions, and in large cities, higher education institutions carry out a more rapid transition to the integrated system of learning that is due not only to the active financing and development of material and technical resources, but also developed legal regional framework, providing legal regulation of this process. However, not all regions of the Russian Federation legislation covers all levels of education, predominantly legal regulation aimed at introducing inclusive education in schools, no institutions of secondary and higher professional education. A similar situation exists in the Krasnodar region. To date, the special regulations to inclusive education in Universities in the Kuban there. Regulatory framework affecting at least partly integrated learning are quite General, conceptual documents, and departmental acts of Executive bodies are primarily intended for the solution of individual questions of the General education system. The study of problems of introduction and development of inclusive education system in Universities based on the study of foreign experience, analysis of Federal and regional legislation (including Krasnodar territory), and taking into account relevant scientific papers, will significantly deepen and expanding the existing system of knowledge about the specifics of legal regulation of integrated education in the system of Russian higher education at the present stage of development.
ANALYSIS AND STRUCTURE OF RUSSIAN DIRECT INVESTMENTS ABROAD
Authors: Izyumova O. N. , Krylova T. A.
Published: July 2018

This article analyzes direct investments. Currently, with the development of market relations and the strengthening of international relations, the objective trends in the growing volume of the export of Russian capital, the increase in its scale and the size of foreign assets, the consolidation of Russian companies in the promising segments of the world market, makes the article relevant and important for consideration. For a more precise presentation of the present situation, the structure of capital flows, in the context of economic entities, as well as statistical data on regulatory measures for foreign direct investment, are provided. The analysis revealed an unfavorable situation on the world investment market for the Russian Federation. The outflow of foreign direct investment from countries with economies in transition tends to decline. Carrying out the analysis of investments it is impossible to bypass. It should be noted that the structure of the capital exported from Russia differs from the similar structure of states with a progressive market by the fact that the share of other investments approximates to the share of foreign direct investment, and this trend increases dramatically in the period of instability. A clearer idea allows us to obtain a detailed analysis of the outflow of Russian investments and the inflow of foreign capital, as given in the paper. The article allows to consider the structure and present position of Russian direct investments and foreign capital.
PEDAGOGICAL STANDARDS AND REQUIREMENTS FOR THE PEOPLE WITH SPECIAL NEEDS AND DISABILITIES TRAINING IN PROFESSIONAL AND EDUCATIONAL ORGANIZATIONS
Authors: Kamenskaya R. A. , Lukyanova V. A.
Published: July 2018

The article is about standards, organizational and pedagogical requirements for the inclusive education realization in the professional educational organizations. The article deals with the detailed requirements for the inclusive education including the methodological support for the adapted educational program and personnel.
THE EFFECTIVENESS OF VIBROSENSITIVITY MATERIALS
Authors: Dmitruk Y. V.
Published: July 2018

Loading and transportation of plastic and bulk cargo is characterized by a decrease of their quality, negative environmental impact and high cost. Improving the efficiency of loading is ensured by the use of a vibrating pipeline transportation of materials, which eliminates the construction of auxiliary structures, does not change the state environment and improves logistics of goods. The analytical results using data from foreign and domestic practice on the issue of delivery of materials. Detailed aspects of the use of the innovative technology of vibro-transportation of cargo. The parameters of transportation of concrete mixtures with the increase in their quality due to the effect of vibration in the pipeline. Justified the optimal parameters of transport of materials with minimization of threats to the environment. Optimization of parameters of transport tailings leaching allows to reduce the level of hazardous chemical pollution in the ecosystems of the environment by leachate. Indicates the direction of obtaining environmental and technological effect from the use at the same time environmental and resource-saving technologies.
FEATURES OF TEACHING LOCAL HISTORY
Authors: Logacheva T. N.
Published: July 2018

The article analyzes the problems of teaching local history in the Volgograd region. The results of a survey among teachers of educational institutions dealing with issues relating to local history. Examines educational and teaching AIDS used in the process of studying the history of his native land.
Öğretmenlerin Özyeterlik Algılarının Çeşitli Değişkenlere Göre İncelenmesi
Authors: AYTAÇ Alper
Published: July 2018

Bu araştırmanın amacı öğretmenlerin özyeterlik algılarını çeşitli değişkenlere göre incelemektir. Tarama modeli ile tasarlanan araştırmanın çalışma grubunu çeşitli branşlardan 249 öğretmen oluşturmaktadır. Verilerin toplanmasında Tschannen-Moran ve Hoy (2001) tarafından geliştirilen ve Çapa, Çakıroğlu ve Sarıkaya (2005) tarafından Türkçe’ye uyarlanan “Öğretmen Özyeterlik Ölçeği” kullanılmıştır. Verilerin analizinde aritmetik ortalama, standart sapma, bağımsız t testi ve tek yönlü varyans analizi kullanılmıştır. Çoklu karşılaştırmalarda ise Tukey testi tercih edilmiştir. Verilerin analizine geçmeden hem ölçek genelinde hem de alt boyutlarda normallik varsayımlarına bakılmıştır. Basıklık ve çarpıklık değerlerinin -1 ile +1 değerleri arasında olduğu tespit edilmiş ve verilerin normal dağıldığı varsayılmıştır. Araştırma sonuçlarına göre öğretmenlerin özyeterlik algıları “yüksek” düzeyde bulunmuştur. Bunun yanı sıra öğretmenlerin özyeterlik algılarının cinsiyete göre anlamlı şekilde farklılaşmadığı, buna karşın branş, görev yapılan yerleşim birimi ve mesleki kıdeme göre anlamlı şekilde farklılaştığı ortaya çıkarılmıştır. Buna göre şehir merkezinde görev alan öğretmenlerin özyeterlik algıları, kırsalda görev alan öğretmenlerin özyeterlik algılarına göre daha yüksektir. Temel eğitim alanı (okulöncesi ve sınıf) öğretmenlerinin özyeterlik algıları, branş öğretmenlerinin özyeterlik algılarına göre daha yüksektir. Son olarak, öğretmenlerin özyeterlik algıları, mesleki kıdem arttıkça yükselmektedir.
Influence of boundary conditions on the response of multilayered plates with cohesive interfaces and delaminations using a homogenized approach
Authors: Massabò R.
Published: July 2018

Stress and displacement fields in multilayered composites with interfacial imperfections, such as imperfect bonding of the layers or delaminations, or where the plies are separated by thin interlayers allowing relative motion, have large variations in the thickness, with characteristic zigzag patterns and jumps at the layer interfaces. These effects are well captured by a model recently formulated by the author for multilayered plates with imperfect interfaces and affine interfacial traction laws (Massabò & Campi, Meccanica, 2014, in press; Compos Struct, 2014, 116, 311-324). The model defines a homogenized displacement field, which satisfies interfacial continuity, and uses a variational technique to derive equilibrium equations depending on only six generalized displacement functions, for any arbitrary numbers of layers and interfaces. The model accurately predicts stresses and displacements in simply supported, highly anisotropic, thick plates with continuous, sliding interfaces. In this paper the model is applied to wide plates with clamped edges and some inconsistencies, which have been noted in the literature for models based on similar approaches and have limited their utilization, are explained. A generalized transverse shear force is introduced as the gross stress resultant which is directly related to the bending moment in the equilibrium equations of multilayered structures with imperfect interfaces and substitutes for the shear force of single-layer theory. An application to a delaminated wide plate highlights the potential and limitations of the proposed model for the solution of fracture mechanics problems.
A consistency assessment of coupled cohesive zone models for mixed-mode debonding problems
Authors: Dimitri R. , Trullo M. , Zavarise G. , De Lorenzis L.
Published: July 2018

Due to their simplicity, cohesive zone models (CZMs) are very attractive to describe mixed-mode failure and debonding processes of materials and interfaces. Although a large number of coupled CZMs have been proposed, and despite the extensive related literature, little attention has been devoted to ensuring the consistency of these models for mixed-mode conditions, primarily in a thermodynamical sense. A lack of consistency may affect the local or global response of a mechanical system. This contribution deals with the consistency check for some widely used exponential and bilinear mixed-mode CZMs. The coupling effect on stresses and energy dissipation is first investigated and the path-dependance of the mixed-mode debonding work of separation is analitically evaluated. Analytical predictions are also compared with results from numerical implementations, where the interface is described with zero-thickness contact elements. A node-to-segment strategy is here adopted, which incorporates decohesion and contact within a unified framework. A new thermodynamically consistent mixed-mode CZ model based on a reformulation of the Xu-Needleman model as modified by van den Bosch et al. is finally proposed and derived by applying the Coleman and Noll procedure in accordance with the second law of thermodynamics. The model holds monolithically for loading and unloading processes, as well as for decohesion and contact, and its performance is demonstrated through suitable examples.
Integrated structure for a resonant micro-gyroscope and accelerometer
Authors: Zega V. , Comi C. , Corigliano A. , Valzasina C.
Published: July 2018

This paper presents the study of the mechanical behavior of a microstructure designed to detect acceleration and angular velocity simultaneously. The new resonant micro-sensor proposed, fabricated by the ThELMA© surface-micromachining technique, bases detection of two components of external acceleration (one in-plane component and one out-of plane component) and two components of angular velocity (roll and yaw) on the variation of frequency of several elements set in resonance. The device, despite its small dimensions, provides a differential decoupled detection of four external quantities thanks to the presence of four slender beams resonating in bending and four torsional resonators.
Estimate of compressive strength of an unidirectional composite lamina using cross-ply and angle-ply laminates
Authors: Scafè M. , Raiteri G. , Brentari A. , Dlacic R. , Troiani E. , Falaschetti M. P. , Besseghini E.
Published: July 2018

In this work has been estimated the compressive strength of a unidirectional lamina of a carbon/epoxy composite material, using the cross-ply and angle-ply laminates. Over the years various methods have been developed to deduce compressive properties of composite materials reinforced with long fibres. Each of these methods is characterized by a specific way of applying load to the specimen. The method chosen to perform the compression tests is the Wyoming Combined Loading Compression (CLC) Test Method, described in ASTM D 6641 / D 6641M-09. This method presents many advantages, especially: the load application on the specimen (end load combined with shear load), the reproducibility of measurements and the experimental equipment quite simplified. Six different laminates were tested in compressive tests. They were realized by the same unidirectional prepreg, but with different stacking sequences: two cross-ply [0/90]ns, two angle-ply [0/90/±45]ns and two unidirectional laminates [0]ns and [90]ns. The estimate of the compressive strength of the unidirectional laminates at 0°, was done by an indirect analytical method, developed from the classical lamination theory, and which uses a multiplicative parameter known as Back-out Factor (BF). The BF is determined by using the experimental values obtained from compression tests.
Damage initiation in brittle and ductile materials as revealed from a fractoluminescence study
Authors: Chmel Alexandre , Shcherbakov Igor’
Published: July 2018

A set of heterogeneous and homogeneous materials differing in their brittle and ductile characteristics (granite, marble, silica ceramics, silicon carbide, organic glass) were subjected to impact damaging by a falling weight. Multiple chemical bond ruptures produced by elastic waves propagating from a damaged zone were accompanied by the photon emission generated throughout the sample (tribo- or fractoluminescence, FL). The statistical analysis of the FL time series detected with high resolution (10 ns) showed that the energy release distributions in brittle solids follow the power law typical for the correlated nucleation of primary defects. At the same time, the formation of damaged sites in ductile materials (marble and organic glass) was found to be fully random.
FE analysis of cruciform welded joints considering different mechanical properties for base material, heat affected zone and weld metal
Authors: Corigliano Pasqualino , Crupi Vincenzo , Guglielmino Eugenio , Fricke Wolfgang
Published: July 2018

The aim of this scientific work was to investigate the behaviour of cruciform welded joints under static loading using a full-field technique: Digital Image Correlation. The material curves, relative to different zones (base material, heat affected zone, weld), were obtained by hardness measurements, which were done by means of a fully automated hardness scanner with high resolution. This innovative technique, based on the UCI method, allowed to identify the different zones and to assess their different mechanical properties, which were considered in the finite element model. Finally the finite element model was validated experimentally, comparing the results with the measurements obtained using the Digital Image Correlation technique.
The effect of thickness on out-of-plane constraint in terms of the T-stress
Authors: Matvienko Yu.G.
Published: July 2018

The plastic zone is theoretically and numerically analyzed for various combinations of the nonsingular terms xx T to zz T ratios in connection with specimen thickness under mode I loading. The plastic zone size distribution is based on the Mises yield criterion for mode I conditions and mapped in the specimen thickness direction. It is shown that the plastic zone size is affected by the zz T -stress, i.e. there is strong effect of out-of-plane constraint (thickness) on crack tip plastic zones. In addition, to study the effect of thickness and loading mode mixity (mode I and II) of the specimen on the singular (KI, KII) and the non-singular ( xx T , zz T ) terms along the 3D crack front, three-dimensional stress fields are analyzed by means of finite element analysis. The strong effect of thickness and mixed mode loading conditions on the zz T -stress is observed. At the same time, there is not the effect of thickness on the nonsingular xx T -stress at the same loading conditions.
In-service fatigue cracking of the propeller shafts joined by a spline-pinned construction to the engines of AN-24, AN-26, and IL-18 aircrafts
Authors: Shanyavskiy A. , Toushentsov A.
Published: July 2018

The paper delivers a critical review of the research data on the crack initiation and crack growth patterns characteristic of the components of the spline-bolted joints between the propeller shaft and reducer shaft at An-24, An-26, and Il-18 aircrafts. Cracks in the shafts nucleated because of reduced bolt-fastening force. Actually, the bolt (bolts) failed first (also by fatigue) and then fatigue cracks nucleated and grew in the shafts, the spline surface fretting zones and/or sharp edges of the attachment (bolt-conducting) holes making the crack origin sites. The crack growth history shows itself through the regular Macro-Beach Marks, each mark sequentially pointing to the next loading event of the propeller shaft, i.e., to each next flight. The cracks cease growing for some while in the airscrews and their shafts just replaced to another aircraft. For the airscrew shafts, the critically assessed data show the crack growth period Np ranging as five to ten percent of a total running period Nf . We recommend performing nondestructive inspection of the airscrew shafts on every 250- hour running period to ensure the safety flights.
Fatigue crack behavior on a Cu-Zn-Al SMA
Authors: Di Cocco V. , Iacoviello F. , Natali S. , Volpe V.
Published: July 2018

In recent years, mechanical property of many SMA has improved in order to introduce these alloys in specific field of industry. Main examples of these alloys are the NiTi, Cu-Zn-Al and Cu-Al-Ni which are used in many fields of engineering such as aerospace or mechanical systems. Cu-Zn-Al alloys are characterized by good shape memory properties due to a bcc disordered structure stable at high temperature called ?-phase, which is able to change by means of a reversible transition to a B2 structure after appropriate cooling, and reversible transition from B2 secondary to DO3 order, under other types of cooling. In ?-Cu-Zn-Al shape memory alloys, the martensitic transformation is not in equilibrium at room temperature. It is therefore often necessary to obtain the martensitic structure, using a thermal treatment at high temperature followed by quenching. The martensitic phases can be either thermally-induced spontaneous transformation, or stressinduced, or cooling, or stressing the ?- phase. Direct quenching from high temperatures to the martensite phase is the most effective because of the non-diffusive character of the transformation. The martensite inherits the atomic order from the ?-phase. Precipitation of many kinds of intermetallic phases is the main problem of treatment on cu-based shape memory alloy. For instance, a precipitation of ?-phase occurs in many low aluminum copper based SMA alloy and presence of ?-phase implies a strong degradation of shape recovery. However, Cu-Zn-Al SMA alloys characterized by aluminum contents less than 5% cover a good cold machining and cost is lower than traditional NiTi SMA alloys. In order to improve the SMA performance, it is always necessary to identify the microstructural changing in mechanical and thermal conditions, using X-Ray analyses. In this work a Cu-Zn-Al SMA alloy obtained in laboratory has been microstructurally and metallographically characterized by means of X-Ray diffraction and Light Optical Microscope (LOM) observations. Furthermore a fatigue crack propagation and fracture surface scanning electron microscope (SEM) observations have been performed in order to evaluate the crack path and the main crack micromechanisms.
On the improved adhesion of NiTi wires embedded in polyester and vinylester resins
Authors: Merlin Mattia , Scoponi Martina , Soffritti Chiara , Fortini Annalisa , Rizzoni Raffaella , Garagnani Gian Luca
Published: July 2018

This paper discusses the effect of different surface treatments on shape memory alloy wires embedded in PolyEster (PE) and VinylEster (VE) polymeric matrices. In particular, two types of chemical etching and a chemical bonding with a silane coupling agent have been performed on the surfaces of the wires. Pull-out tests have been carried out on samples made from a specifically designed Teflon mould. Considering the best results of the pull-out tests obtained with PE resin, the debonding induced by strain recovery of 4%, 5% and 6% pre-strained NiTi wires has been evaluated with the wires being subjected to different surface treatment conditions and then being embedded in the PE matrix. The results prove that the wires functionalised and embedded in the PE resin show the maximum pull-out forces and the highest interfacial adhesion. Finally, it has been found that debonding induced by strain recovery is strongly related to the propagation towards the radial direction of sharp cracks at the debonding region.
Design of a novel magnetorheological damper with internal pressure control
Authors: Golinelli Nicola , Spaggiari Andrea
Published: July 2018

In this work we designed and manufactured a novel magnetorheological (MR) fluid damper with internal pressure control. Previous authors’ works showed that the yield stress ?B of MR fluids depends both on the magnetic field intensity and on the working pressure. Since the increase of the magnetic field intensity is limited by considerations like power consumption and magnetic saturation, an active pressure control leads to a simple and efficient enhancement of the performances of these systems. There are three main design topics covered in this paper about the MR damper design. First, the design of the magnetic circuit; second the design of the hydraulic system and third the development of an innovative pressure control apparatus. The design approach adopted is mainly analytical and provides the equations needed for system design, taking into account the desired force and stroke as well as the maximum external dimensions.
Near tip strain evolution of a growing fatigue crack
Authors: Zhu M.-L. , Lu Y.-W. , Lupton C. , Tong J.
Published: July 2018

Near tip full-field strains in a growing fatigue crack have been studied in situ using the Digital Image Correlation (DIC) technique in a compact tension specimen of stainless steel 316L under tension-tension cyclic loading. An error analysis of displacements and strains has been carried out, and the results show that the precision of displacements and strains in the wake of the crack is worse than that in front of the crack. A method for the determination of crack tip location is proposed for the DIC analysis. Strain ratchetting is observed ahead of the growing fatigue crack tip and found to be dependent on the distance to the crack tip; whilst normal strains appear to stabilise behind the crack tip.
Interpreting experimental fracture toughness results of quasi-brittle natural materials through multi-parameter approaches
Authors: Spagnoli Andrea , Carpinteri Andrea , Vantadori Sabrina
Published: July 2018

Natural stones like marbles are often employed as façade panels to externally cover buildings. These natural materials tend to exhibit a quasi-brittle nonlinear fracture behaviour which, conversely to concrete counterpart, has much less been studied in the literature. In the present paper, an experimental campaign on the so-called red Verona marble is carried out, and the results are discussed together with some previously published results on the white Carrara marble. The analysis of the two marbles as a whole allows us to discuss size effect and to point out the need for additional parameters in order to describe their fracture behaviour. The study focuses on a two-parameter model which accounts for a characteristic material length. A quantitative correlation between material microstructure features, obtained from thin sections technique, and the characteristic material length is proposed.
Fatigue crack tip damaging micromechanisms in a ferritic-pearlitic ductile cast iron
Authors: Iacoviello Francesco , Di Cocco Vittorio , Cavallini Mauro
Published: July 2018

Due to the peculiar graphite elements shape, obtained by means of a chemical composition control (mainly small addition of elements like Mg, Ca or Ce), Ductile Cast Irons (DCIs) are able to offer the good castability of gray irons with the high mechanical properties of irons (first of all, toughness). This interesting properties combination can be improved both by means of the chemical composition control and by means of different heat treatments(e.g. annealing, normalizing, quenching, austempering etc). In this work, fatigue crack tip damaging micromechanisms in a ferritic-pearlitic DCI were investigated by means of scanning electron microscope observations performed on a lateral surface of Compact Type (CT) specimens during the fatigue crack propagation test (step by step procedure), performed according to the “load shedding procedure”. On the basis of the experimental results, different fatigue damaging micromechanisms were identified, both in the graphite nodules and in the ferritic – pearlitic matrix.
Surface crack growth in cylindrical hollow specimen subject to tension and torsion
Authors: Shlyannikov V. , Yarullin R. , Ishtyryakov I.
Published: July 2018

The subject for studies is an aluminium cylindrical hollow specimen with external axial and part circumferential semi-elliptical surface crack undergoing fatigue loads. Both the optical microscope measurements and the crack opening displacement (COD) method are used to monitor and calculate both crack depth and crack length during the tests. The variation of crack growth behaviour is studied under cyclic axial tension, pure torsion and combined tension+torsion fatigue loading. For the particular surface flaw geometries considered, the elastic and plastic in-plane and out-of-plane constraint parameters, as well as the governing parameter for stress fields in the form of In-integral and plastic stress intensity factor, are obtained as a function of the aspect ratio, dimensionless crack length and crack depth. The combined effect of tension and torsion loading and initial surface flaw orientation on the crack growth for two type of aluminium alloys is made explicit. The experimental and numerical results of the present study provided the opportunity to explore the suggestion that fatigue crack propagation may be governed more strongly by the plastic stress intensity factor rather than the magnitude of the elastic SIFs alone. One advantage of the plastic SIF is its sensitivity to combined loading due to accounting for the plastic properties of the material.
Crack tip fields in elastic-plastic and mixed mode I+II+III conditions, finite elements simulations and modeling
Authors: Fremy F. , Pommier S. , Galenne E. , Courtin S.
Published: July 2018

This paper is devoted to the analysis of the load path effect on I+II+III mixed mode fatigue crack propagation in a 316L stainless steel. Experiments were conducted in mode I+II and in mode I+II+III. The same maximum, minimum and mean values of the stress intensity factors were used for each loading path in the experiments. The main result of this set of experiments is that very different crack growth rates and crack paths are observed for load paths that are however considered as equivalent in most fatigue criteria. The experiments conducted in mode I+II and in mode I+II+III, also allowed to show that the addition of mode III loading steps to a mode I+II loading sequence is increasing the fatigue crack growth rate, even when the crack path is not significantly modified.
Critical crack path assessments in failure investigations
Authors: Caligiuri Robert D.
Published: July 2018

This paper presents a case study in which identification of the controlling crack path was critical to identifying the root cause of the failure. The case involves the rupture of a 30-inch (0.76 m) natural gas pipeline in 2010 that tragically led to the destruction of a number of homes and the loss of life. The segment of the pipeline that ruptured was installed in 1956. The longitudinal seam of the segment that ruptured was supposed to have been fabricated by double submerged arc welding. Unfortunately, portions of the segment only received a single submerged arc weld on the outside, leaving unwelded areas on the inside diameter. Post-failure examination of the segment revealed that the rupture originated at one of these unwelded areas. Examination also revealed three additional crack paths or zones emanating from the unwelded area: a zone of ductile tearing, a zone of fatigue, and a zone of cleavage fracture, in that sequence. Initial investigators ignored the ductile tear, assumed the critical crack path was the fatigue component, and (incorrectly) concluded that the root cause of the incident was the failure of the operator to hydrotest the segment after it was installed in 1956. However, as discussed in this paper, the critical path or mechanism was the ductile tear. Furthermore, it was determined that the ductile tear was created during the hydrotest at installation by a mechanism known as pressure reversal. Thus the correct root cause of the rupture was the hydrotest the operator subjected the segment to at installation, helping to increase the awareness of operators and regulators about the potential problems associated with hydrotesting.
Crack paths and the linear elastic analysis of cracked bodies
Authors: Pook L. P.
Published: July 2018

The linear elastic analysis of cracked bodies is a Twentieth Century development, with the first papers appearing in 1907, but it was not until the introduction of the stress intensity factor concept in 1957 that widespread application to practical engineering problems became possible. Linear elastic fracture mechanics (LEFM) developed rapidly in the 1960s, with application to brittle fracture and fatigue crack growth. The first application of finite elements to the calculation of stress intensity factors for two dimensional cases was in 1969. Finite element analysis had a significant influence on the development of LEFM. Corner point singularities were investigated in the late 1970s. It was soon found that the existence of corner point effects made interpretation of calculated stress intensity factors difficult and their validity questionable. In 1998 it was shown that the assumption that crack growth is in mode I leads to geometric constraints on permissible fatigue crack paths. Current open questions are. The need for a new field parameter, probably a singularity, to describe the stresses at surfaces. How best to allow for the influence of corner point singularities in three dimensional numerical predictions of fatigue crack paths. Adequate description of fatigue crack path stability.
Kinetics of fatigue crack growth and crack paths in the old puddled steel after 100-years operating time
Authors: Lesiuk G. , Szata M.
Published: July 2018

The goal of the authors’ investigations was determination of the fatigue crack growth in fragments of steel structures (of the puddled steel) and its cyclic behavior. Tested steel elements coming from the turn of the 19th and 20th were gained from still operating ancient steel construction (a main hall of Railway Station, bridges etc.). This work is a part of investigations devoted to the phenomenon of microstructural degradation and its potential influence on their strength properties. The analysis of the obtained results indicated that those long operating steels subject to microstructure degradation processes consisting mainly in precipitation of carbides and nitrides inside ferrite grains, precipitation of carbides at ferrite grain boundaries and degeneration of pearlite areas [1, 2]. It is worth noticing that resistance of the puddled steel to fatigue crack propagation in the normalized state was higher. The authors proposed the new kinetic equation of fatigue crack growth rate in such a steel. Thus the relationship between the kinetics of degradation processes and the fatigue crack growth rate also have been shown. It is also confirmed by the materials research of the viaduct from 1885, which has not shown any significant changes in microstructure. The non-classical kinetic fatigue fracture diagrams (KFFD) based on deformation (??) or energy (?W) approach was also considered. In conjunction with the results of low- and high-cycle fatigue and gradual loss of ductility as a consequence (due to the microstructural degradation processes) - it seems to be a promising construction of the new kinetics fatigue fracture diagrams with the energy approach.