检索结果-南通市图书馆

A two variable refined plate theory for the bending analysis of functionally graded plates

在线全文

学校读者我要写书评

暂无评论

Acta Mechanica Sinica 2010年第6期26卷 941-949页

作者： Ismail Mechab Hassen Ait Atmane Abdlouahed Tounsi Hichem Abdesselem Belhadj EI Abbas Adda bedia Laboratoire des Materiaux et Hydrologie Universite de Sidi Bel AbbesBP 89 Cite Ben M'hidi22000 Sidi Bel AbbesAlgerie Departement de genie civil Faculte des Sciences de l'IngenieurUniversite Hassiba Benbouali de ChlefChlefAlgerie

Bending analysis of functionally graded plates using the two variable refined plate theory is presented in this *** number of unknown functions involved is reduced to merely four,as against five in other shear deformation theories. The variationally consistent theory presented here has, in many respects,strong similarity to the classical plate theory. It does not require shear correction factors,and gives rise to such transverse shear stress variation that the transverse shear stresses vary parabolically across the thickness and satisfy shear stress free surface *** properties of the plate are assumed to be graded in the thickness direction with their distributions following a simple power-law in terms of the volume fractions of the *** equations are derived from the principle of virtual displacements, and a closed-form solution is found for a simply supported rectangular plate subjected to sinusoidal loading by using the Navier *** results obtained by the present theory are compared with available solutions,from which it can be concluded that the proposed theory is accurate and simple in analyzing the static bending behavior of functionally graded plates.

关键词： fG plates Shear deformation theory Refined plate theory Higher-order theory Navier solution

A New Higher Order Shear Deformation Model for Static Behavior of functionally Graded Plates

在线全文

学校读者我要写书评

暂无评论

Advances in Applied Mathematics and Mechanics 2013年第3期5卷 351-364页

作者： Tahar Hassaine Daouadji Abdelouahed Tounsi El Abbes Adda bedia Universit´e Ibn Khaldoun BP 78 Zaaroura14000 TiaretAlg´erie Laboratoire des Mat´eriaux&Hydrologie Universit´e de Sidi Bel AbbesAlg´erie

In this paper,a new displacement based high-order shear deformation theory is introduced for the static response of functionally graded *** any other theory,the number of unknown functions involved is only four,as against five in case of other shear deformation *** theory presented is variationally consistent,has strong similarity with classical plate theory inmany aspects,does not require shear correction factor,and gives rise to transverse shear stress variation such that the transverse shear stresses vary parabolically across the thickness satisfying shear stress free surface *** mechanical properties of the plate are assumed to vary continuously in the thickness direction by a simple power-law distribution in terms of the volume fractions of the *** illustrations concerned flexural behavior of fG plates with Metal-Ceramic *** studies are performed for varying ceramic volume fraction,volume fraction profiles,aspect ratios and length to thickness *** validity of the present theory is investigated by comparing some of the present results with those of the classical,the first-order and the other higher-order *** can be concluded that the proposed theory is accurate and simple in solving the static behavior of functionally graded plates.

关键词： functionally graded material power law index volume fraction higher-order shear deformation theory Navier solution

free vibration of functionally graded sandwich plates using four-variable refined plate theory

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Applied Mathematics and Mechanics(English Edition) 2011年第7期32卷 925-942页

作者： L.HADJI H.A.ATMANE A.TOUNSI I.MECHAB E.A.ADDA bedia Laboratoire des Matériaux et Hydrologie Université de Sidi Bel AbbesSidi Bel Abbes 22000Algérie Département de Génie Civil Université Ibn KhaldounTiaret 14000Algérie Département de Génie Civil Faculté des Sciences de l'IngénieurUnivesité Hassiba Benbouali de ChlefChlef 02000Algérie

This paper uses the four-variable refined plate theory （RPT） for the free vibration analysis of functionally graded material （fGM） sandwich rectangular plates. Unlike other theories, there are only four unknown functions involved, as compared to five in other shear deformation theories. The theory presented is variationally consistent and strongly similar to the classical plate theory in many aspects. It does not require the shear correction factor, and gives rise to the transverse shear stress variation so that the transverse shear stresses vary parabolically across the thickness to satisfy free surface conditions for the shear stress. Two common types of fGM sandwich plates are considered, namely, the sandwich with the fGM facesheet and the homogeneous core and the sandwich with the homogeneous facesheet and the fGM core. The equation of motion for the fGM sandwich plates is obtained based on Hamilton＇s principle. The closed form solutions are obtained by using the Navier technique. The fundamental frequencies are found by solving the eigenvalue problems. The validity of the theory is shown by comparing the present results with those of the classical, the first-order, and the other higher-order theories. The proposed theory is accurate and simple in solving the free vibration behavior of the fGM sandwich plates.

关键词： functionally graded material (fGM) free vibration sandwich plate refinedplate theory (RPT) Navier solution

Static Analysis of functionally Graded Sandwich Plates Using an Efficient and Simple Refined Theory

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Aeronautics 2011年第4期24卷 432-433页

作者： Hadj Henni ABDELAZIZ Hassen Ait ATMANE Ismail MECHAB Lakhdar BOUMIA Abdelouahed TOUNSI Adda bedia El ABBAS Laboratoire des Matériaux et Hydrologie Université de Sidi Bel Abbes Département de Génie Civil Université Ibn Khaldoun Département de Génie Civil Faculté de Génie Civil et d'Architecture Univesité de Chlef Département de Physique Université de Sidi Bel Abbes

In this paper, a new displacement based high-order shear deformation theory is introduced for the static response of functionally graded sandwich plate. Unlike any other theory, the number of unknown functions involved is only four, as against five in case of other shear deformation theories. The theory presented is variationally consistent, has strong similarity with classical plate theory in many aspects, does not require shear correction factor, and gives rise to transverse shear stress variation such that the transverse shear stresses vary parabolically across the thickness satisfying shear stress free surface conditions. Two common types of functionally graded sandwich plates, namely, the sandwich with fimctionally graded facesheet and homogeneous core and the sandwich with homogeneous facesheet and functionally graded core, are considered. Governing equations are derived from the principle of virtual displacements. The closed-form solution of a simply supported rectangular plate subjected to sinu- soidal loading has been obtained by using the Navier method. The validity of the present theory is investigated by comparing some of the present results with those of the classical, the first-order and the other higher-order theories. It can be concluded that the proposed theory is accurate and simple in solving the static bending behavior of functionally graded sandwich plates.

关键词： functionally graded materials sandwich plates refined plate theory bending Navier solution

ANALYTICAL ANALYSIS Of INTERfACIAL STRESSES IN fRP-RC HYBRID BEAMS WITH TIME-DEPENDENT DEfORMATIONS Of RC BEAM

在线全文

学校读者我要写书评

暂无评论

Acta Mechanica Solida Sinica 2011年第6期24卷 519-526页

作者： Bouazza fahsi Kouider Halim Benrahou Baghdad Krour Abdeloauhed Tounsi Samir Benyoucef1 E Abbas Adda bedia Laboratoire des Matériaux et Hydrologie Université de Sidi Bel Abbes BP 89 Cité Ben M'hidi 22000 SidiBel Abbes Algéri Universitaire Mustapha Stambouli Mascara Département de Génie Civil Algérie Laboratoire des Matériaux et Hydrologie Université de Sidi Bel Abbes BP 89 Cité Ben M’hidi 22000 SidiBel Abbes Algérie

In this paper, the effect of time-dependent deformations （such as shrinkage and creep） on the interracial stresses between an RC beam and fRP plate is presented. for this end, a closed-form solution for such stresses in externally fRP plated RC beams including creep and shrinkage effects is presented. The developed model is formulated to predict the interfacial stresses at time ＇t＇, in which the RC beams have been already subjected to creep and shrinkage effects. The adherend shear deformations have been included in the present theoretical analysis by assuming a parabolic shear stress through the thickness of the RC beam and the fRP panel. Contrary to some existing studies, the assumption that both RC beam and fRP panel have the same curvature is not used in the present investigation. This research is helpful for the understanding on mechanical behavior of the interface and design of the fRP-RC hybrid structures.

关键词： hybrid structure RC beams fRP composites interfacial stresses creep shrinkage

Anchoring of 10-phenylphenothiazine to mesoporous silica materials:A water compatible organic photocatalyst for the degradation of pollutants

在线全文

学校读者我要写书评

暂无评论

Journal of Materials Science & Technology 2022年第8期103卷 134-143页

作者： Daniel González-Muñoz Almudena Gómez-Avilés Carmen B.Molina Jorge bedia Carolina Belver Jose Alemán Silvia Cabrera Organic Chemistry Department Science FacultyUniversidad Autónoma de Madrid28049 MadridSpain Chemical Engineering Department Science FacultyUniversidad Autónoma de Madrid28049 MadridSpain Institute for Advanced Research in Chemical Sciences(IAdChem) Universidad Autónoma de Madrid28049 MadridSpain Inorganic Chemistry Department Science FacultyUniversidad Autónoma de Madrid28049 MadridSpain

The application of organic photocatalysts towards the oxidation of pollutants in water is hampered by different limitations such as their insolubility in the ***,we report that the grafting of a photoorganocatalyst into mesoporous silica materials is an ideal approach to obtain effective ***,the photocatalyst 10-phenylphenothiazine(PTH)was easily anchored into three different mesoporous silica-based materials(MSN,MSU-2 and SBA-15)with different particle sizes and pore sizes through an amide bond *** materials were characterized using IR analysis,solid-state X-ray diffraction,porosity and microscopy(SEM and TEM)techniques,showing that PTH is immobilized inside the pores of the materials and its optical properties are maintained after the *** homogeneous PTH was inactive in water media,the three photocatalytic materials were active for the degradation of ***-15-AP-PTH exhibited the highest catalytic performance towards the degradation of acetaminophen and diclofenac under solar irradiation,finding in this manner a new strategy for the decontamination of pollutants.

关键词： Organic semiconductors Silica support Solar photocatalysis Water treatment Pharmaceuticals

Natural frequencies of composite beams with a variable fiber volume fraction including rotary inertia and shear deformation

在线全文

学校读者我要写书评

暂无评论

Applied Mathematics and Mechanics(English Edition) 2009年第6期30卷 717-726页

作者： Y. Bedjilili A. Tounsi H. M. Berrabah I. Mechab E. A. Adda bedia S. Benaissa Université de Tlemcen Faculté des Sciences de l'ingénieurDépartement de Génie MécaniqueAlgérie Laboratoire des Matériaux et Hydrologie Université de Sidi Bel AbbesAlgérie Laboratoire de Mathématiques Université de Sidi Bel AbbesAlgérie

The present study is concerned with the vibration analysis of symmetric composite beams with a variable fiber volume fraction through thickness. first-order shear deformation and rotary inertia have been included in the analysis. The solution procedure is applicable to arbitrary boundary conditions. Continuous gradation of the fiber volume fraction is modeled in the form of an m-th power polynomial of the coordinate axis in the thickness direction of the beam. By varying the fiber volume fraction within the symmetric composite beam to create a functionally graded material （fGM）, certain vibration characteristics are affected. Results are presented to demonstrate the effects of shear deformation, fiber volume fraction, and boundary conditions on the natural frequencies and mode shapes of composite beams.

关键词： free vibration functionally graded materials first-order shear deformationtheory

Role of high definition colonoscopy in colorectal adenomatous polyp detection

在线全文

学校读者我要写书评

暂无评论

World Journal of Gastroenterology 2011年第35期17卷 4001-4006页

作者： Tolga erim John M Rivas Evelio Velis fernando Castro Department of Gastroenterology Cleveland Clinic FloridaWestonFL 33331United States Department of Internal Medicine Cleveland Clinic FloridaWestonFL 33331United States Health Services Administration Master Program Barry UniversityMiami ShoresFlorida 33161United States

AIM:To investigate the rates of polyp detection in a mixed risk population using standard definition (SDC) vs high definition colonoscopes (HDC).METHODS:This was a retrospective cohort comparative study of 3 colonoscopists who each consecutively performed 150 SDC (307,200 pixel) and 150 HDC (792,576 pixels) in a community teaching ***:A total of 900 colonoscopies were evaluated (mean age 56,46.8% men),450 with each *** of any type were detected in 46.0% of patients using SDC and 43.3% with HDC (P=0.42).There was no significant difference between the overall number of polyps,HDC (397) and SDC (410),detected among all patients examined,(P=0.73).One or more adenomatous polyps were detected in 24.2% of patients with HDC and 24.9% of patients with SDC colonoscopy (P=0.82).There was no significant difference between HDC (M=0.41) and SDC (M=0.42) regarding adenomatous polyp (P=0.88) or advanced adenoma (P=0.56) detection rate among all patients ***:HDC did not improve yield of adenomatous polyp,advanced adenoma or overall polyp detection in a population of individuals with mixed risk for colorectal cancer.

关键词： High definition colonoscopy Colon cancer screening Adenomatous polyps

The fatty Acid Composition of Butter Stored in Sheep’s or Goat’s Stomach (Karinyagi)

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

food and Nutrition Sciences 2011年第5期2卷 402-406页

作者： Ilhan Gun bedia Simsek Mehmet Akif Ersoy University Vocational School Department of Food Processing Dairy ProductsProgramme Burdur Turkey

Butter is produced from cream or yoghurt in dairy factories and farms and called as butter or yayik butter in Turkey. Karinyagi is also made from cream and yoghurt as yayik butter, but the packaging material is different from others. Karinyagi produce by filling of butter into purified goat’s and sheep’s stomach (the traditional name is Karin) and storage in this material during self-life. The aim of this study was to determine the fatty acid composition of Karinyagi made from cream. Twenty Karinyagi samples were randomly collected from different regions of Burdur/Turkey. The fatty acid composition of samples (by gas chromatography) and chemical properties was investigated. It was deter-mined that the chemical properties of Karinyagi was similar to butter produced with cream and yoghurt. The total saturated fatty acid level of Karinyagi samples changed from 62.31 to 76.64 (mean value 67.14 ± 3.36)%, while unsaturated fatty acids of them ranged from 20.48 to 31.57 (mean value 28.46 ± 2.67)%. Minimum and maximum levels of monounsaturated fatty acids of karinyagi were determined as 18.98 % and 28.57%. Butyric, oleic and palmitic acids were dominant in Karinyagi. Palmitic acid was slightly lower comparing to data for butter produced with cream and yoghurt. As a result, the amount of Karinyagi fatty acids may be said to be significantly different from the fatty acid of yayik and cream butter.

关键词： Karinyagi Butter fatty Acid Compositions