bluuebunny/crossref_metadata_2025 huggingface dataset:
Rotina de procedimentos utilizados na seleção e adaptação de aparelhos de amplificação sonora individual em centros auditivos na cidade de Porto Alegre, Brasil - RS
Authors: Zandavalli Mariele Boscaini , Christmann Letícia Selbach , Garcez Vera Regina Carvalho
Published: March 2009

OBJETIVOS: verificar a rotina de procedimentos realizados com pacientes candidatos ao uso de aparelho de amplificação sonora individual, em Centros Auditivos na cidade de Porto Alegre, Rio Grande do Sul no Brasil. MÉTODOS: participaram do estudo 14 Centros Auditivos, por meio de questionário preenchido pelo fonoaudiólogo (a), responsável técnico (a) pelo estabelecimento. RESULTADOS: os resultados encontrados indicaram que os únicos procedimentos realizados em 100% dos centros auditivos foram a audiometria tonal limiar, a otoscopia e a pré-moldagem. Quanto ao tipo de aparelhos auditivos, moldes auriculares e tecnologia mais indicados foram retroauriculares, invisíveis simples e digitais, respectivamente. Na adaptação a faixa etária mais comumente foi de 60 a 79 anos, o tipo de adaptação monoaural, e a maioria dos centros auditivos realizam orientações de uso, acompanhamento após aquisição e experiência domiciliar prévia. CONCLUSÃO: os resultados mostraram que não existiram divergências entre os centros auditivos pesquisados, mas que alguns procedimentos teriam importância significativa para o processo de seleção de aparelhos auditivos, pois os mesmos contribuiriam para o sucesso de uma protetização efetiva.
Efeitos ambientais e genéticos sobre escores visuais e ganho de peso à desmama de animais formadores da raça Brangus
Authors: Queiroz Sandra Aidar de , Costa Gabriela Zoccolaro , Oliveira João Ademir de , Fries Luiz Alberto
Published: March 2009

Estudaram-se os efeitos da idade da vaca ao parto e da idade do animal à desmama, bem como os efeitos genéticos aditivo direto e materno e da heterozigose individual, sobre os escores visuais de conformação, precocidade e musculatura e ganho de peso do nascimento à desmama, de animais formadores da raça Brangus. Foram analisados 53.683, 45.136, 52.937 e 56.471 dados de conformação, precocidade e musculatura à desmama e ganho de peso do nascimento à desmama, respectivamente, de animais nascidos entre 1986 e 2002, provenientes do arquivo zootécnico da empresa Gensys Consultores Associados S/C Ltda. Os efeitos de ambiente e genéticos sobre as características em estudo foram analisados pelo método de quadrados mínimos usando modelos matemáticos que incluíram grupo de contemporâneos como variável classificatória e a idade da vaca ao parto, a idade do animal à desmama e os efeitos aditivo direto e materno e da heterozigose individual como co-variáveis. Todos os efeitos incluídos nos modelos afetaram significativamente as características avaliadas, com exceção do efeito da idade da vaca ao parto sobre o ganho de peso do nascimento à desmama e do efeito aditivo materno sobre todas as características estudadas. Os efeitos ambientais e genéticos revelaram-se importantes fontes de variação para as características estudadas e devem, pois, ser considerados na distinção e comparação dos animais para seleção.
Comportamento de ovinos em capim-tanzânia sob lotação rotativa com quatro níveis de suplementação concentrada
Authors: Pompeu Roberto Cláudio Fernandes Franco , Rogério Marcos Cláudio Pinheiro , Cândido Magno José Duarte , Neiva José Neuman Miranda , Guerra José Lúcio Lima , Gonçalves Josemir de Souza
Published: March 2009

Avaliou-se o comportamento de ovinos em pastagem de capim-tanzânia irrigado sob suplementação (0,0; 0,6; 1,2 e 1,8% PV) com concentrado. O delineamento utilizado foi o inteiramente casualizado com seis repetições (ovinos). A porcentagem do tempo total sob o sombrite, pastejando, ruminando, em "outras atividades", em ócio, o número de ingestões de suplemento/sal, de defecações, de micções e de ingestão de água e a taxa de bocado foram estimados dividindo-se o dia em oito períodos de 3 horas (das 5 às 8 h; 8 às 11 h; 11 às 14 h; 14 às 17 h; 17 às 20 h; 20 às 23 h; 23 às 2 h; 2 às 5 h). O tempo de pastejo foi maior entre os animais que não receberam suplementação e decresceu progressivamente, voltando a elevar somente com 1,8% de suplementação. O tempo de ruminação foi maior nos animais com suplementação de 0,6% PV, principalmente das 14 às 17 h e das 17 às 20 h, enquanto o tempo de ócio foi maior no nível de 1,2% PV. A ingestão de água elevou-se com o aumento da suplementação até 1,2% PV e concentrou-se entre 11 e 14 h. O número de micções e de defecações foi maior com suplementação no nível de 1,8% PV. A elevação progressiva na taxa de bocado até o nível de suplementação de 1,2% PV no período das 11 às 20 h com posterior redução sugere efeito aditivo do suplemento sobre o pasto até esse nível, no qual se inicia efeito substitutivo. O tempo sob o sombrite concentrou-se no período das 8 às 14 h e reduziu com a suplementação até 1,2% PV. A suplementação afeta o comportamento ingestivo de ovinos em pastejo, uma vez que, no nível de 1,2% PV, houve otimização da capacidade ingestiva dos animais. Níveis superiores de suplementação comprometem o comportamento ingestivo, por isso, são necessárias alterações na formulação do suplemento quando utilizados níveis mais elevados.
Composição química e degradabilidade in situ da ração em ovinos em área de caatinga no sertão de Pernambuco
Authors: Santos Gladston Rafael de Arruda , Batista Ângela Maria Vieira , Guim Adriana , Santos Mércia Virginia Ferreira dos , Matos Daniele Silva de , Santoro Kleber Régis
Published: March 2009

Objetivou-se avaliar o efeito do tipo de fístula e da hora de coleta sobre a composição química e a degradabilidade in situ da ração em ovinos criados na caatinga. Foram utilizados dez ovinos mestiços de Santa Inês (cinco com cânula no rúmen e cinco com cânula no esôfago) recebendo água e mistura mineral ad libitum. Os percentuais de matéria seca (MS) variaram de 11,99 a 25,28%, matéria mineral (MM), 10,92 a 14,44%, proteína bruta (PB), 10,64 a 17,19%, extrato etéreo (EE), 2,95 a 4,77%, fibra em detergente neutro (FDN), 54,83 a 63,14%, fibra em detergente ácido (FDA), 39,40 a 46,62%, proteína insolúvel em detergente neutro (PIDN), 49,74 a 57,95%, proteína insolúvel em detergente ácido (PIDA), 28,52 a 39,15%, carboidratos totais (CT), 65,40 a 72,73%, carboidratos não-fibrosos (CNF), 5,47 a 12,86%, fenóis totais (FT), 0,37 a 0,52%, taninos totais (TT), 0,16 a 0,28% e taninos condensados (TC), 1,28 a 6,24%, respectivamente. A degradabilidade potencial variou de 48,25 a 64,63% para MS; 36,43 a 54,34% para FDN; e de 62,13 a 77,24% para proteína; a fração B, de 35,77 a 47,78% para MS; 33,28 a 50,38% para FDN; e 35,44 a 56,09% para proteína; a fração C, de 4,60 a 13,40% para MS; 3,84 a 8,42% para FDN; e 5,37 a 14,36% para proteína; a fração A, 9,74 a 18,13% para MS; 2,16 a 4,41% para FDN; e 20,21 a 31,49% para proteína; a degradabilidade efetiva para a taxa de passagem de 2%/hora, de 43,28 a 55,71 para MS; 29,21 a 36,54 para FDN; 55,84 a 67,49 para proteína; e a degradabilidade efetiva para a taxa de passagem de 5%/hora, de 37,60 a 47,27 para MS; 23,02 a 33,33 para FDN; e 45,74 a 59,99 para proteína. A composição química e a degradabilidade in situ da ração em ovinos foi influenciada pelo mês de avaliação. A dieta apresentou baixa digestibilidade in situ da MS, FDN e PB. A fistula ruminal, em comparação à fistula de esôfago, permitiu melhor avaliação da dieta, em virtude da recuperação total da extrusa.
Iridium-Catalyzed Isomerization of Primary Allylic Alcohols
Authors: Mantilli Luca , Mazet Clément
Published: March 2009

A readily accessible iridium hydrogenation catalyst displays high reactivity for the isomerization of primary allylic alcohols under mild reaction conditions. Key to the efficiency of the catalytic system is to deviate from the conventional hydrogenation route in favor of the desired
isomerization pathway by adequately tuning the reaction conditions as indicated by preliminary mechanistic investigations.
Evaluating Continuing Competency: A Challenge for Nursing
Authors: Allen Patricia , Lauchner Kathryn , Bridges Ruth Ann , Francis-Johnson Patricia , McBride Susan G. , Olivarez Arturo, Jr
Published: March 2009

Twenty-five nurse leaders met at an invitational conference in Texas to discuss professional nurse competency evaluation. Conference attendees who were statewide nursing leaders in practice, education, and administration identified ways to evaluate competency. Responses were recorded and clustered into the following patterns: (1) components of competency evaluation, (2) barriers and challenges to evaluating competency, and (3) recommendations for evaluating competency. Conference attendees reported competency includes the abilities to think in action, have confidence and clarity in decision making, and retrieve information throughout the career trajectory. Nurses must demonstrate the ability to access evidence-based information and synthesize it within the context of practice situations. Self-reflection and self-assessment are necessary components to competency evaluation for the improvement of nursing practice.
Increasing Understanding of Nursing Research for General Duty Nurses: An Experiential Strategy
Authors: Sawatzky-Dickson Doris M. , Clarke Diana E.
Published: March 2009

Misconceptions and trepidation about research abound among practicing nurses. However, in light of the movement toward increasing accountability to consumers and the concurrent drive toward evidence-based practice, the need for nursing research can no longer be ignored. Innovative approaches to augment nurses’ training and education in research and evidence-based practice must be incorporated into continuing education programs. The Nursing Research and Evidence-Based Practice Committee of a large tertiary care teaching hospital in Winnipeg, Manitoba, Canada, developed a series of opportunities for staff nurses to participate in research projects and have ongoing exposure to the steps in the research process. The Great Canadian Cookie Experiment was an opportunity to participate in quantitative research. Qualitative data from patients’ thank you cards were analyzed in an interactive fashion during luncheon seminars held during Nursing Week in 2 subsequent years. A survey of nurses who participated in the luncheon seminars indicated an overall increase in their knowledge about qualitative research methods and an appreciation for participating in the process of nursing research. Continued visibility of nursing research will contribute to changing nurses’ attitudes toward fostering an evidence-based approach to clinical practice.
SWOT Is Useful in Your Tool Kit
Authors: DeSilets Lynore D. , Dickerson Pamela S.
Published: March 2009

The components of SWOT are addressed in this column as a methodology to identify a department's strengths, weaknesses, opportunities, and threats.
J Contin Educ Nurs
2008;39(5):196–197.
Continuing Professional Competence: Peer Feedback Success From Determination of Nurse Locus of Control
Authors: Mantesso Jaime , Petrucka Pammla , Bassendowski Sandra
Published: March 2009

Continuing competence programs (CCPs) are becoming required in many nursing jurisdictions across Canada. CCPs have the common goal of ensuring nurses remain up-to-date and competent in their professional practice. They often incorporate reflective practice as a tool for nurses to critically explore their practice and professionalism on an ongoing basis. Feedback is one of the strategies within reflective practice which enables nurses to increase reflective capabilities and enhance professional performance through collegial exchange. Locus of control, a personality variable, is considered as a potential indicator of how receptive nurses may be toward CCPs. For CCPs to be optimally embraced by nurses, it is imperative that professional nursing bodies address nurses' loci of control in developing, supporting, and strategizing for reflective practice, generally, and feedback, specifically.

J Contin Educ Nurs
2008;39(5):200–205.
An Academic Service Partnership to Expand Capacity: What Did We Learn?
Authors: Murray Teri A.
Published: March 2009

This article highlights the educational needs that emerged when an academic institution and a hospital partnered to produce more nurses in response to the registered nurse shortage. The partnership proposed to offer quality clinical experiences for students by having the hospital-paid nurse clinicians serve as faculty. This would enable the academic partner to increase enrollment amid limited faculty resources. The qualitative feedback received may prove useful in (1) guiding the professional development activities of future nurse clinicians who participate in education–service partnerships to expand educational capacity; (2) assisting academic nursing program administrators and faculty to expand capacity without compromising quality; and (3) assisting hospital nurse administrators to weigh risks and returns to pursue mutually beneficial outcomes.

J Contin Educ Nurs
2008;39(5):217–224.
Argument Mapping
Authors: Billings Diane M. , Kowalski Karren
Published: March 2009

Argument mapping is an analytical technique that can also be used as an educational tool to assist learners at all levels of their education develop skills of advanced critical thinking and clinical decision making.

J Contin Educ Nurs
2008;39(6):246–247.
Creative Education for Rapid Response Team Implementation
Authors: Johnson Amy L.
Published: March 2009

The Institute for Healthcare Improvement advocates implementation of rapid response teams (RRTs) to bring experts to the bedside to assist with patient assessment and treatment. Due to shrinking budgets and limited resources, initiating new programs and policies can be challenging in the health care environment. This article highlights a creative approach that a community hospital used to provide staff education during the RRT implementation process. This education plan includes a review of learning considerations, creation of a video, and other strategies that could be used by staff development educators for a variety of other topics.

J Contin Educ Nurs
2009;40(1):38–42.
Fracture Simulation of Randomly Cracked Material with Various Crack Length Distributions
Authors: Sato Kazushi , Hashida Toshiyuki
Published: March 2009

In this paper, cracking behavior of distributed microcracks is discussed using a numerical simulation. The microcracks are initially distributed in a rectangle region. The directions and locations of the cracks are chosen at random. Three kinds of length distributions are used, such as a uniform length, a random length distribution and a fractal length distribution. The crack propagations from the initially distributed cracks are analyzed under a uniaxial tensile load using liner elastic fracture mechanics.
The global behaviors of various crack distribution are studied. Results obtained from the numerical calculations indicate that the effect of the crack length distribution is minor in term of the macroscopic behavior of the cracked body.
Fatigue Life Prediction of Impacted Glass/Epoxy Composites under Variable Amplitude Loading
Authors: Kang Ki Weon , Kim Jong Kweon
Published: March 2009

This paper presents the fatigue behavior of plain-weave E-glass/epoxy composites with impact-induced damage under constant and variable amplitude loading. The constant amplitude fatigue life of the impacted composites can be identified through the prediction model, which was proposed on the carbon/epoxy laminates by authors. Also, the models are derived to calculate the equivalent stress of the composites under variable amplitude loading, considering the impact damage. These
models allow fatigue data of the unimpacted and impacted composites under variable amplitude loading to be correlated with constant amplitude data of the unimpacted composites.
Application of the Unified Strength Theory in Analyzing Fracture Strength
Authors: Yu M.H. , Fan W. , Che A.L. , Yoshimine M. , Iwatate Takahiro
Published: March 2009

In practical engineering, the cracks are always mixed mode. The research on the mixed fracture criterion has an important significance in fracture mechanics and engineering. Stress state of the mixed mode cracks is complicated. A new unified strength theory considering the effects of all the three principal stresses is generalized into the fracture mechanics in this paper. The complex stress states are common characteristics between the mixed mode cracks and the unified strength theory. A unified fracture function criterion is established by using the unified strength theory in this paper. In the unified fracture function, the difference between tension and pressure and the effect of the intermediate principal stress σ2 are considered. With the variation of α = σt/ σc and failure parameter b , a series of mixed mode crack criteria are formed, and can be applied for many materials. The J-integral is calculated through FEM. According to the relation between the result and the stress intensity factor, Klc can be obtained. Then it is used in the unified fracture function. The unified fracture criterion is compared with those of other mixed mode criterions.
Inverse Analysis to Estimate Critical Crack Propagation Parameters for Elastic-Plastic and Graded Materials
Authors: Nakamura Toshio , Wang Zi Qiang
Published: March 2009

Accurate crack propagation simulation requires critical fracture parameters to be known a priori. For elastic-plastic materials, two fundamental parameters are the separation energy and the peak stress required to generate new crack surfaces. In general, both are difficult to quantify since direct determinations are not possible in experiments. For inhomogeneous materials, such as graded materials, determination is even more complex since these parameters vary spatially. In this paper, a novel method based on an inverse analysis technique is proposed to estimate the fracture parameters of elastic-plastic and graded media. The method utilizes the Kalman filter to process measured data and extract best estimates of the unknown parameters. The accuracy of the method is examined in a verification study where a dynamically propagating crack in double cantilever beam type specimen is modeled. In the study, time variation records of crack opening displacement, opening strain, crack advance distance, and load point reaction force are used as possible measurements. Despite large noises in data, the results confirm accurate estimation. The estimates improve when multiple measurements are supplied to the inverse technique.
Local Stress Field for Torsion of a Penny-Shaped Crack in a Functionally Graded Strip
Authors: Feng Wen Jie , Hao R.J. , Wang Li Bin , Liu Juan
Published: March 2009

The torsion of a penny-shaped crack in a functionally graded strip is considered. Hankel transform is used to reduce the problem to solving a Fredholm integral equation. The crack tip stress field is obtained by considering the asymptotic behavior of Bessel function. Investigated are the effects of material property parameters and geometry criterion on the stress intensity factor. Numerical results show that increasing the gradient of shear modulus can suppress crack initiation
and growth, and that the stress intensity factor varies little with the increasing of the strip's highness.
Effect of Cavitation Number on the Improvement of Fatigue Strength of Carburized Steel Using Cavitation Shotless Peening
Authors: Macodiyo D.O. , Soyama H. , Saka Masumi
Published: March 2009

Peening can be used to produce a layer of compressive residual stress at the surface of components which are subject to fatigue or stress corrosion, thereby retarding crack initiation and/or impeding the development of new cracks and hence improving their fatigue life. We have developed a new peening method, Cavitation Shotless Peening (CSP), which makes use of cavitation impacts induced by the collapse of the cavitation bubbles to produce compressive residual stress and work hardening on the material surface. CSP is a surface enhancement technique which differs with shot peening in that shots are not used. CSP uses a submerged high-speed water jet with cavitation, herein referred to as a cavitating jet, whose intensity and occurring region can be controlled by parameters such as upstream pressure and nozzle size. Cavitation number , which is defined by the ratio of upstream pressure to downstream pressure, is the main parameter of the cavitating jet. In this paper, the pit distribution on the specimen was observed with cavitating numbers  = 0.0057 and  = 0.0142. The improvement of fatigue strength and introduction of residual stress were investigated for both conditions using carburized alloy steel (JIS SCM415). It was evident from a comparison between non-peened and cavitation shotless peened specimens that the cavitation number has influence on the fatigue strength of metallic materials. Comparison of shot peened and CSP specimens has also been discussed.
Probabilistic Estimation of the Fatigue Life of an Electric Car Bogie Frame
Authors: Goo Byeong Choon , Seo Jung Won
Published: March 2009

Bogie frames of electric cars play an important role as a structural member for the support of vehicle loading. To guarantee more than 25 years' durability, a lot of study has been carried out for the prediction of the fatigue life of the bogie frame in experimental and theoretical domains. One of the new methods being applied in recent years for rolling stock structures is a reliability-based approach.
In this paper, using one of these methods, we estimate fatigue life of the bogie frame of an electric car, which was developed by the Korea Railroad Research Institute. First of all, we have carried out tensile fatigue tests with several types of specimens: as-welded, ground on weld toe, reinforcement-removed and post weld heat treated specimens for each type aforementioned. In addition, we perform the probabilistic distribution tests of the S-N curves for the ground specimens. Normal, lognormal and Weibull distributions are used to model the distributions. Along with the obtained S-N relations, we use two approaches to evaluate the fatigue life of the bogie frame. In the first approach probabilistic distribution of the S-N curve is used. The S-N curves are obtained in function of failure percent from the specimen tests. Then the fatigue life is estimated by use of Miner-Palmgren hypothesis. In the second approach, load spectra measured by strain gauges are approximated by a two variable Weibull distribution. And a limit state function for the criterion of failure is derived by use of Miner-Palmgren hypothesis. The fatigue life is evaluated by a reliability engineering method.
A Study on the Evaluation of Material Degradation of 1Cr-1Mo-0.25V Steel Using Ultrasonic Techniques
Authors: Kim Jeong Pyo , Bae Bong Kook , Seok Chang Sung
Published: March 2009

It's required that mechanical properties of in-service facilities maintain the safety of operation in power plants as well as chemical plants. In this study the four classes of thermally aged 1Cr-1Mo-0.25V specimens were prepared using an artificially accelerated aging method at 630°C. Ultrasonic tests, tensile tests, KIC
tests and hardness tests were performed in order to evaluate the degree of the
material degradation. The mechanical properties deteriorated as the specimen degraded, but the attenuation coefficient and the harmonic generation level of the ultrasonic signal increased. The non-linear parameter derived from the harmonic generation level is especially sensitive and will be a good parameter to evaluate the material degradation.
An Energy Gradient Fracture Criterion Based on Virtual Crack Vector Model with Application to T-Stress Problem
Authors: Liu D.A. , Li Li Yun , Yuan Q.F. , Cheng D.X.
Published: March 2009

A virtual crack vector model is proposed in this paper to simulate the branched crack propagation and simplify its calculation of energy release rate. An energy gradient fracture criterion is constructed based on this model. It can take account of the effects of biaxial loads or T-stress on brittle mixed mode fracture and agrees well with the test data of biaxial tensile fracture and the specially conducted experiment of the influences of ox on the mixed mode fracture of plexiglas. Considering its advantage of predicting initial propagation angle and critical fracture stress independently without the determination of the core region radius, it can be used as a practical fracture criterion for brittle mixed mode fracture under biaxial tension.
Damage Detection of Beams Based on Experimental Wavelet Analysis of Flexible Waves
Authors: Li Zheng , Xia Shuman , Fan J.W. , Su Xian Yue
Published: March 2009

In this paper, the continuous wavelet transform by the Gabor wavelet is applied to analyzing
flexural waves in a cantilever beam with an edge crack. The amplitudes and arrival times of the
incident, reflected and transmitted waves at a certain frequency are extracted from the wave signals
to identify the damage location exactly and estimate the damage extent qualitatively. The results
show that this is an effective damage detection method and can be extended to the damage detection
of complicated structures.
Effect of HfC Addition on Mechanical Properties of Nb-5Mo-2W-18Si In-Situ Composites
Authors: Wang Sheng Wu , Hirai Hisatoshi , Tabaru Tatsuo , Kitahara A. , Ueno Hideto
Published: March 2009

Nb base in-situ composites with the base composition of Nb-5Mo-2W-18Si were prepared by conventional arc-melting and induction heating floating zone melting followed by directional solidification. To investigate the effect of HfC addition, Nb was replaced with 0, 1 and 2 mol% HfC. The in-situ composites predominantly have an eutectic microstructure consisting of Nb solid solution (NbSS) and (Nb,Mo,W))5Si3 (5-3 silicide). The strength at 1470 K and 1670 K increases without fracture toughness decreasing, with increasing the HfC content. Directional solidification also improves the strength at the high temperature. The slip band under the shearing stress occurs in the NbSS during plastic deformation, which contributes to suppress microcrack propagation. It seems that HfC addition reinforces the bonding strength at grain boundary or NbSS/5-3 silicide interface.
Fracture Behaviors of Multi-Crack in Rock-Like Material
Authors: Li Li Yun , Che F.X. , Liu D.A.
Published: March 2009

Multi-crack problems are deeply involved in rock-like material and rock engineering. In order to study the influences of lateral stress and inclined crack angle on the failure load of the multi-cracked body, uniaxial and biaxial compression fracture tests are conducted on plate specimens with regular distributed multi-cracks. The stress distribution and the stress intensity factors KI and KII for every crack tips of the specimens are calculated by FEM. The experiment revealed that the failure load of the multi-cracked specimens increase obviously with the increase of the lateral pressure σ2 and the inclined crack angle α. And the multi-cracked specimens will hardly initiate propagation under equal biaxial compression. Analyses have been shown that these can be explained by the variation of KII with the σ2 and the α.
Study on the Joint Open Deformation Using Joint Interface Element in the Shiplock of the Three Gorges Project
Authors: Sheng Qian , Huang Zheng Jia , Yang Chun He
Published: March 2009

In light of the open deformation of joints in the middle isolated pier of the permanent shiplocks of Three Gorges Project(TGP), a typically simplified joint model is set up based on the geological conditions and the crack investigation. The method of joint interface element is used to analyze the joint open deformation and study the characteristic of open joints. The results show that the open deformation and the open length of joints are directly related to their occurrence and geometrical
character.
Hydro-Mechanical Coupling Analyses of Cofferdam Stability of Taian Pumped Storage Power Station
Authors: Li Shu Cai , Li Shu Chen , Zhu Wei Shen , Chen Wei Zhong , Zhang Le Wen , Chau K.T.
Published: March 2009

Three-dimensional hydro-mechanical coupling analyses have been conducted on the
water-tight structure of the cofferdam for both intake and outlet of Taian pumped storage power station, located in Shandong Province of China. In addition, the effects of excavation on the cofferdam and foundation slopes were also studied by using the 3D FLAC. The calculation results show that the central core of high-pressure grouting has a prefect anti-seepage effect and therefore is able to strengthen the stability of the cofferdam and foundation slopes. The excavation process has only some local effects on the cofferdam and does not greatly affect the global stability of the cofferdam. Therefore, no failure takes place around slope toes. The results show that the width of platform left on the excavation side is reasonable.
A New Three-Dimensional FEM Model on Arch Dam Cracking Analysis
Authors: Lin P. , Zhou W.Y. , Yang Q. , Hu Yu Jing
Published: March 2009

In this paper, a new three dimensional FEM model was elucidated on arch dam cracking
analysis. Based on the least potential energy method, the stiffness of the interface between two
types of mesh is coupled into the whole stiff matrix in this model. By this means, the FEM mesh of
local area of arch dam can be easily changed from a coarse mesh to a fine mesh. By changing the
density of mesh, the consideration of heterogeneity for the calculating elements is achieved by
assigned to the elements random strength and elastic modulus according to a Weibull distribution.
This model allows to densify the mesh of a local area and to trace the cracking of this area
undertake damage criterion. By applying this new model, the mechanism of vertical cracks opening
along the downstream surface of Shuanghe Arch Dam after two years of operation was briefly
analyzed. The numerical result is basically agreed with the field investigation.
The Effect of the Incidence Direction of Stress Wave on Cracks
Authors: Chen Jing Xi , Zhang Guang , Liu Shi Qi
Published: March 2009

The writer has performed a series of dynamic breaking tests for researching impact of incidence direction of stress wave on rectangle plaster plank with cracks in its center and stress-strain relation’s variation and distribution on rectangle plaster plank with time under impacting action of stress wave, especially analyzing and testing breaking direction, developing route and sequence under the specific conditions of that incidence angles between cracks and stress wave are 0°, 30°, 45°, 60° and 90°.
Transient Anti-Plane Crack Problem in a Functionally Graded Smart Structure
Authors: Zou Z.Z. , Chen J. , Wu Sheng Xing
Published: March 2009

The dynamic anti-plane crack problem in a functionally graded smart structure is considered. Integral transforms are employed to reduce the problem to the solution of singular integral equations. Numerical results are presented to show the nfluences of electrical crack condition, crack position, electromechanical combination factor and material gradient parameter on the fracture behavior.
Strength and Impact Damage Characteristics of Al7075/CFRP Sandwich Panel
Authors: Yoon Han Ki , Lee Jae Hyup , Park Yi Hyun , Park J.S.
Published: March 2009

Carbon fiber reinforced aluminum layer laminate (CARALL), which were consisted of various numbers of CFRP prepregs, adhesive films and aluminum sheets, were fabricated by an autoclave. Impact damage behaviors of carbon fiber reinforced plastic (CFRP) and CARALL were investigated. The impact damage resistance of CARALL was significantly higher than that of CFRP. Compression after impact (CAI) tests was conducted to investigate the effect of impact damage on the compression strength of CARALL and CFRP specimens. The CAI strength of CFRP and CARALL decreased with increase of impact energy. However, CAI strength of CARALL is higher than that of CFRP, which can be attributed to the excellent impact damage absorbability of aluminum sheet in CARALL.
Strength and Fracture of Single Crystal Metal Nanowire
Authors: Wu Heng An , Soh Ai Kah , Wang Xiu Xi , Sun Z.H.
Published: March 2009

Numerical simulations have been carried out to determine the mechanical property of single crystal copper nanowire subjected to tension using the molecular dynamics method. The mechanism of deformation, strength and fracture are elucidated based on these numerical simulations. No strengthening is found after yielding of the single crystal nanowire. The simulation results show that the strength of copper nanowire is far greater than that of realistic polycrystalline bulk copper. By decreasing the size of the nanowire's cross-section, which leads to an increase of the ratio of surface atoms, the yield stress is increased. The strain rate has an influence on strength, and mechanism of deformation and fracture. When the strain rate is comparatively low, plastic deformation arises from dislocation slips and twins. However, when the strain rate is sufficiently high, amorphization is a dominant factor of plastic deformation and super-plasticity is found. The fracture process is
demonstrated using the atomic images.
Relation between Stress Intensity Factor of a Small Edge Interface Crack and Intensity of Free-Edge Stress Singularity of Bonded Dissimilar Materials
Authors: Ioka Seiji , Kubo Shiro
Published: March 2009

When two materials are bonded, the free-edge stress singularity usually develops near the intersection of the interface and the free-surface. Fracture in bonded dissimilar materials may therefore occur from an interface crack which develops at the intersection of interface and free-surface. Free-edge stress singularity is very important in the evaluation of strength of bonded dissimilar materials. In this study, the relationship between the stress intensity factor of a small edge crack on interface of bonded dissimilar materials and the intensity of free-edge stress singularity of bonded dissimilar materials with no crack under external mechanical loading was investigated numerically by using the boundary element method. The relationship was also investigated theoretically by using the principle of superposition. The results of numerical analyses were compared with those of theoretical analyses. It was found that stress intensity factors of small edge
crack on interface K1 and K2 were proportional to the intensity of free-edge stress singularity of bonded dissimilar materials Kσ without crack irrespective of the combination of materials. The
numerically determined proportional coefficient between K1 and Kσ agreed well with the theoretical one, and was not affected by crack length when proper normalizations were applied. From these results, it is suggested that stress intensity factor of small edge crack on interface can be used as a
strength criterion of interface of bonded dissimilar materials.
Mode III Interfacial Edge Crack in a Magnetoelectroelastic Bimaterial
Authors: Soh Ai Kah , Liu Jin Xi
Published: March 2009

This paper deals with a Mode III interfacial edge crack in a magnetoelectroelastic bimaterial subjected to line singularities such as an out-of-plane line force, a line electric charge, a line magnetic charge and a straight screw dislocation. The surfaces (including crack surfaces) of the bimateral are assumed to be electrically open and magnetically closed. The closed-form analytical solution to the problem is obtained by employing the complex variable approach in conjunction
with the conformal mapping technique. The intensity factors of stress, electric displacement and magnetic induction are given explicitly. The obtained results can be used as the Green's function to solve more complicated problems.
Parametric Study of Combined Adhesive-Riveted Lap Joints
Authors: Fongsamootr Thongchai , Dechwayukul Charoenyut , Kamnerdtong Notsanop , Rubin Carol A. , Hahn George T.
Published: March 2009

Riveted lap joints are widely used to assemble complex structures, e.g. aircraft fuselages. A thin layer of adhesive (sealant), is normally applied to lap joints in order to restrict the entry of moisture and retard corrosion. In this work, combined adhesive-riveted lap joints were studied to understand the effect of three parameters: panel thickness, adhesive stiffness and adhesive layer thickness, on single row non-countersunk riveted lap joints. Finite element analysis (FEA), along
with Thin Adhesive Layer Analysis (TALA-developed for simulating the adhesive layer in lap joint models), were used to analyze the joint behavior. In previous studies, the stress concentration factor for single row riveted lap joints was found to be approximately 6.1, and the stress concentration factor for sealed riveted lap joints was approximately 5.2 for a 180 micron thick sealant layer. In this study, panel thickness, adhesive stiffness and adhesive layer thickness were varied parametrically in FEA analyses to determine their affects on the joints. The FEA/TALA results were used to predict the fatigue life of the joints as functions of the three parameters. The results show that the maximum tensile stress is smaller with a smaller panel thickness. The results also showed that the stress concentration factor in the joints was reduced when the stiffness of the adhesive layer was increased or when the thickness of the adhesive layer was decreased. Finally, fatigue tests showed that the fatigue life of the combined adhesive-riveted lap joints was greater than for riveted lap joints without adhesive.
Effects of Surface Treatment and Loading Speed on Adhesive Strength of Aluminum to Polycarbonate Lap Joints
Authors: Seo Do Won , Yoon Ho Chel , Lee J.Y. , Lim Jae Kyoo
Published: March 2009

The bonding strength of adhesive joints is influenced by the surface roughness of the joining parts. However, the magnitude of the influence has not yet been clarified because of the complexity of the phenomena. In this study, it is showed that surface treatment affects adhesive strength and durability of aluminum/polycarbonate single-lap joints, and loading speed affects tensile-shear strength of adhesive joints. To evaluate the effect of surface treatments on the adhesive strength, several surface treatment methods are used, that is, cleaning, grinding, SiC polishing and sand
blasting. It is showed that an optimum value of the surface roughness exists with respect to the tensile-shear strength of adhesive joints. The adhesive strength shows linear relationship with the surface roughness and loading speed. And the mechanical removal of disturbing films of lubricants, impurities and oxides make adhesive strength increase significantly.
The Performance Advancement of Test Algorithm Using Neural Network for Semiconductor Packages
Authors: Kim Jae Yeol , Sim Jae Ki , Song M.J. , Kim Chang Hoi , Kwac Lee Ku
Published: March 2009

Availability of defect test algorithm that recognizes exact and standardized defect information in order to fundamentally resolve generated defects in industrial sites by giving artificial intelligence to SAT(Scanning Acoustic Tomograph), which previously depended on operator’s decision, to find various defect information in a semiconductor package, to decide defect pattern, to reduce personal errors and then to standardize the test process was verified. In order to apply the algorithm to the lately emerging Neural Network theory, various weights were used to derive results for performance advancement plans of the defect test algorithm that promises excellent field applicability.
Fracture Strength of WC-12Co Thermal Sprayed Coating under Mixed Loading Mode I&III in Crack Surface Displacement
Authors: Kaneko Kenji , Ohmori Akira , Hiraishi T.
Published: March 2009

Fracture strength of WC-12Co thermal sprayed coating is investigated experimentally and analytically. In the experiments, one pair of butt cylindrical specimen with coating is subjected to combined tension with torsion stresses. Fracture loci were obtained for three kinds of thickness of the coating in σ-τstress plane. Stress distributions at crack tip singular point on fractured surfaces are analyzed by Finite-Element-Method and approximated by the expression σ＝KR-λ where R means normalized thickness coordinate. It is found that the normal stress distributions are common to all cases of testing stress conditions and so fracture condition of the brittle coating is represented as K≧Kcr in the normal stress distribution even under mixed deformation mode I and III. A critical shear stress distribution for separation could also be obtained
Evaluation of Interfacial Strength by Multi-Stages Peel Test
Authors: Omiya Masaki , Inoue Hisahiro , Kishimoto Kikuo
Published: March 2009

Multi-layer thin films are widely used in micro-sensor and microelectronics products. These electronic devices contain several metal or polymer thin films and reliability of these systems is strongly dependent on the interfacial adhesion of these thin films. Due to the thermal stress, residual stress or elastic mismatch, the delamination between layers sometimes occurs. Therefore, it is important to evaluate the interfacial strength precisely. Peel tests are simple way to estimate an interfacial strength and, in fact, widely used in industrial field. Recently, a new simple but
functional device for peel tests has developed in our group. This test method is called 'Multi-stages peel test'. There are two features in this device. At first, peeling tips can be observed continually and it becomes easy to measure a peeling angle. Second is that the peeling angle can be varied by attaching dead weights on the specimen. This dead weight works as a shear force at the peeling tip and the peeling angle can be changed variously. Therefore, the fracture tests under various phase
angles are possible. In this paper, Multi-stages peel test is applied to the evaluation of interface strength of multi-layer thin films that are composed of Cu, Cr, PI and Si layers. By considering the energy balance during the peel test, the interfacial strength independent of the thickness can be obtained.
Meshless Method Used in Wave Propagation in Anisotropic Material
Authors: Ge Dong Yun , Lu Ming Wan , Lu Qiu Hai
Published: March 2009

The compactly supported radial basis functions (RBFs) is modified and used to the wave propagation in the anisotropic materials. An example to simulate the wave propagation in composite material is used in the paper to verify this method. In this example, stress wave propagation histories are obtained. The comparison between results by this method and by finite element method is also made. And the agreement with two results shows that this method can be used to simulate the wave propagation history in anisotropic material efficiently.
Reliability Analysis of Steam Turbine Blade Using Monte Carlo Simulation
Authors: Kim Chul Su , Kim Jung Kyu
Published: March 2009

In this study, the reliability analysis of the low pressure steam turbine blade was performed using
the Monte Carlo simulation considering variations of applied stress and strength. Applied stress
under the service condition of steady state was obtained by finite element analysis. The fatigue
strength under rotating bending load was evaluated by the staircase method. The most appropriate
probabilistic distribution of the fatigue strength is 3-parameter Weibull distribution, which is
determined by the comparative analysis. The failure probability under various loading conditions
was derived from the strength-stress interference model.
The Implementation of Inter-Element Model for Crack Growth Simulation
Authors: Ariffin Ahmad Kamal , Huzni Syifaul , Mohamed Nik Abdullah Nik , Nor Mohd Jailani Mohd
Published: March 2009

The implementation of inter-element model to simulate crack propagation by using finite element analysis with adaptive mesh is presented. An adaptive finite element mesh is applied to analyze two-dimension elastoplastic fracture during crack propagation. Displacement control approach and updated Lagrangean strategy are used to solve the non-linearity in geometry, material and boundary for plane stress crack problem. In the finite element analysis, remeshing process is based on stress error norm coupled with h-version mesh refinement to find an optimal mesh. The
crack is modeled by splitting crack tip node and automatic remeshing calculated for each step of crack growth. Crack has been modeled to propagate through the inter-element in the mesh. The crack is free to propagates without predetermine path direction. Maximum principal normal stress criterion is used as the direction criteria. Several examples are presented to show the results of the implementation.
Numerical Modeling of the Constitutive Relationship of a Soft Rock Using a 3-D Elastic Visco-Plastic Model
Authors: Su Li Jun , Liao Hong Jian , Yin Jian Hua
Published: March 2009

In this paper, a diatomaceous soft rock is studied. Triaxial tests had been conducted on this soft rock. From the test results, it is found that the stress-strain curve of this soft rock has a notable strain-softening tendency. In order to study its time-dependent stress-strain behavior, a constitutive model that can describe not only the strain-hardening behavior, but also the strain-softening behavior must be constructed. Based on Perzyna’s fundamental assumptions of the elastic visco-palstic theory, a visco-plastic flow rule, and Yin and Graham’s 3-D elastic visco-palstic constitutive model (3-D EVP model), the constitutive formulation under a triaxial stress state is obtained in this paper. The derived formulation can be used to simulate the time-dependent stress-strain behavior of both consolidated undrained and consolidated drained triaxial tests of soils and rocks. In this paper, the constitutive formulation is used to simulate the time-dependent stress-strain behavior of consolidated undrained triaxial tests of the soft rock studied in this paper. The simulated results are compared with the triaxial test results. The comparison of the results shows that model predictions agree well with measured results. This demonstrates that the EVP model can be used to describe the time-dependent stress-strain behavior of the soft rock studied in this paper.
Effects of Meso-Scale Structure and Interactions on Macro-Scale Mechanical Properties in Polymeric Materials
Authors: Shinozaki Akira , Omiya Masaki , Inoue Hisahiro , Kishimoto Kikuo
Published: March 2009

The mechanical properties of polymers are strongly influenced by meso-scale structure such as entanglement, orientation, folded chain, etc. However, the relationship between the meso-scale structure and macro-scale mechanical properties of polymers has not been clarified. In this paper, network models of polymer chains are introduced to simulate the meso-scale interactions. From the FEM analysis of this model, the effects of interactions on macro-scale mechanical properties are investigated.
Behaviors of Composite Circular Struts in Space Environment: Analyses and Experiments
Authors: Kim Chul , Lee Jong Heun , Kim J.H. , Choi Hoon Sang
Published: March 2009

The optimal stacking sequence and wall thickness of the composite strut tubes were determined to minimize thermal strains during orbital operation using generic algorithms and finite element analyses. From the results of previous thermal analyses of composite struts with various stacking sequences, the axial deformation is a matter of prime importance. For this reason, the optimization focuses to minimize the axial strains. The balanced and symmetric stacking sequences are used to
minimize the radial and the twisting deformations. The genetic algorithm is known to be very effective for the discrete optimization such as stacking sequences of composite materials. As a result, the thermal deformations of the strut with an optimal stacking sequence are almost zero. The optimal strut tube consists of 6 plies and the weight of a composite strut is 22.4% that of aluminum strut. Finite element analyses showed that the optimal design of composite strut tubes withstood combined launch loads without buckling and failure. To validate the analyses, four composite struts were fabricated and their thermal strains were measured under the temperature increase of 100°C. The thermal and vibration experiments showed excellent correlations with analytical results.