Artykuły w czasopismach: „Θ"/θ' plates”

1

Ouinas, Djamel, i Belkacem Achour. "Buckling analysis of laminated composite plates [(θ/−θ)] containing an elliptical notch". Composites Part B: Engineering 55 (grudzień 2013): 575–79. http://dx.doi.org/10.1016/j.compositesb.2013.07.011.

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Hamani, N., D. Ouinas, N. Taghezout, M. Sahnoun i J. Viña. "Effect of Fiber Orientation on the Critical Buckling Load of Symmetric Composite Laminated Plates". Advanced Materials Research 629 (grudzień 2012): 95–99. http://dx.doi.org/10.4028/www.scientific.net/amr.629.95.

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In this study, a buckling analysis is performed on rectangular composite plates with single and double circular notch using the finite element method. Laminated plates of carbon/bismaleimde (IM7/5250-4) are ordered symmetrically as follows [(θ/-θ)2]S. The buckling strength of symmetric laminated plates subjected to uniaxial compression is highlighted as a function of the fibers orientations. The results show that whatever the notch radius, the buckling load is almost stable. Increasing the degree of anisotropy significantly improves critical buckling load.

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3

Wang, Q. W., W. Q. Tao, Z. Lin i T. T. Chow. "An Experimental Investigation of Natural Convection in a Cubic Inclined Enclosure With Multiple Isolated Plates". Journal of Heat Transfer 122, nr 1 (17.09.1999): 176–79. http://dx.doi.org/10.1115/1.521452.

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Natural convection in a cubic inclined enclosure with three isolated plates was investigated experimentally. The influences of the plates’ spacing, the inclination angles of the enclosure, and the Rayleigh number on the heat transfer of the plate group were obtained. It was found that under a fixed Rayleigh number, there is a plate spacing at which the heat transfer rate of the three plates is approximately the same for the horizontal plate group. Under the range of Rayleigh numbers considered, the heat transfer rate of the plate group is less than that of the natural convection of the plate group in infinite space. The heat transfer rate of the plates increases with the plate inclined angle tilting from θ=90 deg to θ=0 deg, with the most steep increase occurring in the range of θ=90 deg to 45 deg. A global correlation of the heat transfer results for all the inclination between 0 deg and 60 deg can be obtained as Nul,m=0.5360Ralcos θ0.25 with a spread of ±8.9 percent. [S0022-1481(00)00501-6]

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4

Ono, Yuzo, i Nobuo Nishida. "Holographic zone plates for f · θ and collimating lenses". Applied Optics 25, nr 5 (1.03.1986): 794. http://dx.doi.org/10.1364/ao.25.000794.

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Oshima, Nagayasu, Y. Iwai, T. M. Kojima, Tokihiro Ikeda, Y. Kanazawa, M. Hoshino, Ryoichi Suzuki i Y. Yamazaki. "Guiding of a Slow Positron Beam with a Glass Capillary". Materials Science Forum 607 (listopad 2008): 263–65. http://dx.doi.org/10.4028/www.scientific.net/msf.607.263.

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Slow positron beam was injected into a non-tapered glass capillary which was tilted angle of θ from the beam axis by a movable stage. Beam profiles of the positrons transported through the capillary were observed with a phosphor screen combined with micro channel plates as a function of θ. Some fraction of positrons was deflected with the tilting angle of the capillary.

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6

Hamani, N., Djamel Ouinas, N. Benderdouche i Mohamed Sahnoun. "Buckling Analyses of the Antisymetrical Composite Laminate Plate with a Crack from Circular Notch". Advanced Materials Research 365 (październik 2011): 56–61. http://dx.doi.org/10.4028/www.scientific.net/amr.365.56.

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In this study, an analysis of buckling was carried out on composite rectangular plates with and without circular notch by using the finite element method. The graphite/epoxy laminated plates were arranged antisymmetrically in the following ordered way [(θ/-θ)2]s. The buckling strength of the asymmetrical laminated plates subjected to uniaxial load is determined as a function of fiber orientation. The results show that whatever the notch radius, the buckling load is almost stable. The cumulated effect due to the presence of the longitudinal and transverse cracks as well as a circular notch reduces the buckling load considerably, which increases the risk of the fracture.

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7

Fang, Xueqian, Chao Hu i Wenhu Huang. "Dynamic Stress Concentration of a Circular Cutout Buried in Semi-Infinite Plates Subjected to Flexural Waves". Journal of Applied Mechanics 74, nr 2 (4.02.2006): 382–87. http://dx.doi.org/10.1115/1.2198545.

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In this paper, based on the theory of elastic thin plates, applying the image method and the wave function expansion method, multiple scattering of elastic waves and dynamic stress concentration in semi-infinite plates with a circular cutout are investigated, and the general solutions of this problem are obtained. As an example, the numerical results of dynamic stress concentration factors are graphically presented and discussed. Numerical results show that the analytical results of scattered waves and dynamic stress in semi-infinite plates are different from those in infinite plates when the distance ratio b∕a is comparatively small. In the region of low frequency and long wavelength, the maximum dynamic stress concentration factors occur on the illuminated side of scattered body with θ=π, but not on the side of cutout with θ=π∕2. As the incidence frequency increases (the wavelength becomes short), the dynamic stress on the illuminated side of cutout becomes little, and the dynamic stress on the shadow side becomes great.

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8

Ould Hamouda, Sara, Nabil Kazi Tani i Tawfik Tamine. "Numerical buckling analysis of cracked Bi-material thin plates". Advances in Mechanical Engineering 12, nr 7 (lipiec 2020): 168781402094464. http://dx.doi.org/10.1177/1687814020944646.

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The aim of this present study is to analyze numerically the buckling behavior of cracked thin bi-material structures subjected to compression and tensile stresses and this, by considering the evolution of crack lengths and its orientations at the interface. This research work allows to quantify numerically the buckling phenomenon which can affects the thin plates for both cases, with and without interface crack especially, when the plate is subjected to tensile loading. The main important results of numerical simulations show that for the case of compression loading, the presence of interfacial crack increases significantly the strength of the thin plate against buckling phenomena. In the other hand, thin crack plates buckling is more pronounced when the crack tip is close to the interface (θ = 90°, θ = 75°). Finally, unlike to the case of homogeneous thin plates, the incorporation of bi-material aspect in thin plates design offers more strength against buckling either for compression or tensile loading.

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9

WU, W. X., C. SHU, C. M. WANG i Y. XIANG. "FREE VIBRATION AND BUCKLING ANALYSIS OF HIGHLY SKEWED PLATES BY LEAST SQUARES-BASED FINITE DIFFERENCE METHOD". International Journal of Structural Stability and Dynamics 10, nr 02 (czerwiec 2010): 225–52. http://dx.doi.org/10.1142/s021945541000349x.

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It is well-known that stress singularities occur at the obtuse corners of skew plates, especially when the skew angles are large. Owing to the stress singularities, accurate bending results, vibration frequencies and buckling loads of highly skewed plates are difficult to obtain accurately. In this paper, the mesh-free least squares-based finite difference (LSFD) method is proposed for solving the free vibration and buckling problems of highly skewed plates. As such vibration and buckling results are scarce in the open literature, the method was verified by comparing the LSFD solutions with existing ones having a skew angle θ ≤ 70°, or by carrying out convergence studies. The vibration and buckling results for plates with very large skew angle (θ = 80°) are presented for the first time. The close agreement observed in the comparison studies and the good convergence behavior of the LSFD solutions provide the confidence that these vibration and buckling results predicted by the LSFD method are of good accuracy.

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10

Shimamoto, Akira, Hiroshi Ohkawara i Jeong Hwan Nam. "Influence of Anisotropic Properties Upon Stress Intensity Factors under Biaxial Stress". Key Engineering Materials 385-387 (lipiec 2008): 193–96. http://dx.doi.org/10.4028/www.scientific.net/kem.385-387.193.

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In this study, stress intensity factors were investigated and determined by photoelastic and caustics methods to clarify the mechanical behavior of crack tips under various biaxiality ratios. Polycarbonate (PC) plates with isotropic and anisotropic properties were used as specimens. The results confirmed that regardless of biaxiality ratio or the material’s property only ‘KI’ was generated in cases of a crack angle θ = 0º. It was also confirmed that only KI was generated in the isotropic PC plate with crack angle θ = 45º under a biaxial load (1:1). When the biaxiality ratio is more than 1:1 with a crack angle θ = 45º, both KI and KII are simultaneously generated in the isotropic specimen. Furthermore, KI, and KII values are influenced most by the extrusion direction in the anisotropic specimens as the biaxiality load ratios increase.

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11

Bhattacharya, Paramita, i Jyant Kumar. "Pullout capacity of inclined plate anchors embedded in sand". Canadian Geotechnical Journal 51, nr 11 (listopad 2014): 1365–70. http://dx.doi.org/10.1139/cgj-2014-0114.

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The pullout capacity of an inclined strip plate anchor embedded in sand has been determined by using the lower bound theorem of the limit analysis in combination with finite elements and linear optimization. The numerical results in the form of pullout factors have been presented by changing gradually the inclination of the plate from horizontal to vertical. The pullout resistance increases significantly with an increase in the horizontal inclination (θ) of the plate especially for θ > 30°. The effect of the anchor plate–soil interface friction angle (δ) on the pullout resistance becomes extensive for a vertical anchor but remains insignificant for a horizontal anchor. The development of the failure zone around the anchor plates was also studied by varying θ and δ. The results from the analysis match well with the theoretical and experimental results reported in literature.

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12

Aktaş, Mehmet. "Buckling Behaviour of Carbon/Epoxy Laminated Composite Plates under Biaxial Loading". Advanced Composites Letters 18, nr 3 (maj 2009): 096369350901800. http://dx.doi.org/10.1177/096369350901800303.

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In this numerical and analytical study; the length-to-thickness ratio (a/t), aspect ratio (a/b), Young modulus ratio ( E1/ E2), load ratio ( Nx/ Ny) and different boundary conditions effect on buckling behaviour of carbon/epoxy composite laminated plate were investigated. The composite plate was assumed four plies as [θ°]4. The fibre orientation, θ, was chosen as 0°, 15°, 30°, 45°, 60°, 75° and 90°. The Veres-Kollar approach [ 1 ] was used to calculate the buckling load, analytically. Also, ANSYS 10 commercial software was used for determination of buckling load, numerically. The plate has simple supported boundary condition at four edges during analytical and numerical study. Good agreements between analytical and numerical results were obtained. Results showed that the buckling load changes depend on the dimension and material properties of the plate, boundary conditions and loading cases.

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13

Zuiko, Ivan, Vladislav Kulitckii i Rustam Kaibyshev. "Effect of Pre-Straining Method on Mechanical Properties of Thermo-Mechanically Processed Al-Cu-Mg Alloy". Defect and Diffusion Forum 385 (lipiec 2018): 364–69. http://dx.doi.org/10.4028/www.scientific.net/ddf.385.364.

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The present study deals with the effect of pre-deformation technique of AA2519 alloy (Al–5.64Cu–0.33Mn–0.23Mg–0.15Zr–0.11Ti–0.09V–0.08Fe–0.01Si (wt. %)) under T8 tempers, on condition that intermediate strains are equal. After undergoing T87 by pre-stretching and peak ageing the alloy demonstrates the yield stress, ultimate tensile strength and elongation to failure of 425.4±2.4 MPa, 475±2.4 MPa, 12.1±0.4%, respectively. The 7% pre-straining by rolling leads to-5% decrease in yield stress, practically the same ultimate tensile strength and-20% decrease in ductility. This effect can be ascribed to more homogeneous distribution of dislocations which act as heterogeneous nucleation sites for the θ′-phase precipitation. In addition to precipitates of the Al–Cu family (θ′′ and θ′), Ω-phase plates on {111}α habit plane was observed. The effect of pre-straining prior to ageing on the precipitation behavior and its relation with mechanical properties of the AA2519 is considered.

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14

Srinivasan, R. S., i L. S. Ramachandra. "Axisymmetric Nonlinear Dynamic Response of Bimodulus Annular Plates". Journal of Vibration and Acoustics 112, nr 2 (1.04.1990): 202–5. http://dx.doi.org/10.1115/1.2930113.

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In the present study, the geometrically nonlinear dynamic response of bimodulus annular and circular plates is obtained. The governing equations of the problem are formulated using the energy method and are solved by using annular finite elements spacewise. The integration in the time domain is accomplished by the Wilson θ method. Numerical work has been done for different hole sizes under various edge conditions and loadings.

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15

Bravo, J. C. V., H. P. Oquendo i J. E. M. Rivera. "Optimal Decay Rates for Kirchhoff Plates with Intermediate Damping". TEMA (São Carlos) 21, nr 2 (22.07.2020): 261. http://dx.doi.org/10.5540/tema.2020.021.02.261.

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In this paper we study the asymptotic behavior of Kirchhoff plates with intermediate damping. The damping considered contemplates the frictional and the Kelvin-Voigt type dampings. We show that the semigroup those equations decays polynomially in time at least with the rate t^{-1/(2-2θ)}, where θ is a parameter in the interval [0,1[. Moreover, we prove that this decay rate is optimal.

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16

Achour, B., D. Ouinas, M. Touahmia i M. Boukendakdji. "Buckling of Hybrid Composite Carbon/Epoxy/Aluminum Plates with Cutouts". Engineering, Technology & Applied Science Research 8, nr 1 (20.02.2018): 2393–98. http://dx.doi.org/10.48084/etasr.1224.

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Structural instability becomes an important concern in the composite plate safe and reliable design. In this research, a resistance analysis is carried out on plates made of hybrid composite material with and without elliptical cutouts using the finite element method. The carbon/epoxy/aluminum laminated plates are arranged in the following ordered manner [Al/(θ/-θ)/Al]. The hybrid plate resistance to buckling submitted to uniaxial compression is highlighted. Results indicate that given a structural geometry, boundary and loading condition and stacking sequence, the buckling resistance of such plates is strongly influenced by the ply orientation, the anisotropy ratio, and the cutout presence, position and size. The critical load reduction is found to decrease linearly with the decrease of the geometric ratio a/b. When b=8a, the reduction factor N* increased from 1.8% to 7% when φ=90ο and φ=0ο respectively regardless of the ply orientation. Maximum reduction of the buckling critical load is important when the elliptical cutout is located in the middle of the plate. Regardless of the declination of the elliptical cutout, maximum reduction of the critical buckling stress is obtained when the ratio E2/E1=1.

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17

Gable, Brian M., i Barry C. Muddle. "Factors Influencing the Heterogeneous Nucleation of θ' in Al-Cu-In Alloy". Materials Science Forum 519-521 (lipiec 2006): 585–90. http://dx.doi.org/10.4028/www.scientific.net/msf.519-521.585.

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The ability to improve mechanical properties through trace alloying additions that enhance the precipitation-hardening response has been a cornerstone of aluminium research and alloy development. It is now known that many of these alloying additions are beneficial (or deleterious) because of their influence on the competitive precipitation kinetics, in many cases arising from the formation of chemical and structural heterogeneities in the matrix. In order to better our understanding of this phenomenon, the earliest stages of microstructural evolution of indium precipitates and θ' plates in an Al-Cu-In ternary alloy have been investigated. Quantitative microstructural characterization reveals that there is a correlation between the size of the pre-existing indium particle and the resulting heterogeneous precipitation kinetics, with larger indium particles favouring θ' precipitation.

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18

Kostopoulos, V., i D. Th Korontzis. "Damping Characteristics of Vibrated Composite Plates". Advanced Composites Letters 9, nr 6 (listopad 2000): 096369350000900. http://dx.doi.org/10.1177/096369350000900604.

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The free vibration response of [±Θ] ns orthogonal, simply supported (all around) composite laminated plates was studied, assuming linear viscoelastic behaviour of the constitutive lamina material. The problem was solved numerically and the results were verified in the special case of [0]2 n laminate against the analytical solution, which is also provided. Stability and convergence problems were discussed analytically. Eigenfrequency values and modal damping characteristics were calculated for the first nine mode shapes. Furthermore, keeping constant the plate thickness, the effect of the lamina thickness on the vibration characteristics of the plate was examined.

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19

Gouné, M., A. Redjaïmia, T. Belmonte i H. Michel. "Identification and characterization of a novel Mn–N nitride formed in Fe–Mn–N alloy". Journal of Applied Crystallography 36, nr 1 (21.01.2003): 103–8. http://dx.doi.org/10.1107/s0021889802020101.

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An unexpected phase, formed throughout the ferritic matrix of an Fe–Mn (1.62 wt% Mn) alloy during a nitriding treatment at 843 K for 8 h, is analysed. This new phase, labelled θ′, is a metastable Mn nitride. It adopts the form of plates, with length 200 nm and width 20 nm. Its crystal structure is established by electron microdiffraction in conjunction with group-theory analysis. This nitride crystallizes in the tetragonal system and belongs to the space groupP 42/m 2/m 2/cwith the following lattice parameters: a_{\theta'} = 2.876 Å and c_{\theta'} = 5.752 Å. The θ′-phase crystal lattice is oriented with respect to the surrounding ferritic matrix according to the cube-on-cube orientation relationship, namely: (100)_{\theta'} || (200)_\alpha, (010)_{\theta'} || (020)_\alpha and (002)_{\theta'} || (002)_\alpha.

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Migranov, N. G., i D. V. Kondratyev. "Layered anisotropic liquids: deformation of structures in electric and magnetic fields". Proceedings of the Mavlyutov Institute of Mechanics 12, nr 2 (2017): 214–18. http://dx.doi.org/10.21662/uim2017.2.032.

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On the basis of the analysis of the free energy of a viscoelastic anisotropic layer liquid, a chiral ferroelectric liquid crystal C^∗ , located in a thin cell in a ”bookshelf“ geometry the possibility of the smectic layers periodic distortions in the external magnetic H and electric E fields applied perpendicularly and along the plates, respectively, are investigated. The polar angle θ formed by the unit vector n and the normal a to the smectic planes is fixed, and the appearing Helfrich–Yuro distortions u of the smectic layers are assumed to be small in the proposed continuum model of the liquid ferroelectrics.

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21

Zhou, Zhao Zhong, Ju Long Yuan, Bing Hai Lv i Jia Jin Zheng. "Study on the Evaluation Method of Lapping Uniformity for Ceramic Balls". Advanced Materials Research 53-54 (lipiec 2008): 147–54. http://dx.doi.org/10.4028/www.scientific.net/amr.53-54.147.

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To study the sphere-shaping mechanism under dual rotating plates (DRP) lapping mode for ceramic balls, the uniformity of lapping trace distribution is focused in this paper. Methods for simulation and evaluation of the lapping trace uniformity are proposed, and the effect of velocity parameters on the lapping uniformity of ball under DRP lapping mode is analyzed. It is found that the lapping uniformity is dependent not only on the variation range of spin angle θ, but also on the spin angle speed ωb and on the variation form of θ. The analysis results indicate that the effect of amplitude of the speed ratio function on the lapping uniformity is much greater than the effect of phase on that. When the ratio of the inner plate speed to the outer varies from 0 to2, the best lapping uniformity is obtained under the conditions demanded by this paper.

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22

Jones, L. R., T. Shanks i R. Fong. "Angular Correlations of Faint (B<24) Galaxies". Symposium - International Astronomical Union 130 (1988): 528. http://dx.doi.org/10.1017/s0074180900136575.

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We investigate the two point angular correlation function, ω(θ), of faint galaxy samples obtained from COSMOS machine measurements of 3.9m AAT plates. The area of sky used is the largest yet covered to very faint limits(bj<24 over 2.1 deg2 and rF<22 over 1.4 deg2). The power law slope of ω(θ) is found to be consistent with a value of −0.8 at all depths in both passbands (see fig.1). The amplitudes measured by different authors show a large scatter in the blue passband (see fig.2). If this scatter also appied to the red passband (fig.3) we conclude that although a smaller clustering amplitude in the past is preferred, it is not possible to rule out the stable clustering model, and that models in which the clustering is co-moving may be inconsistent with the data.

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23

Fong, R., N. Metcalfe i T. Shanks. "Photometric Calibration and Large-Scale Clustering in the Universe". Symposium - International Astronomical Union 161 (1994): 295–300. http://dx.doi.org/10.1017/s0074180900047513.

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The machine measurements of UK Schmidt plates have produced two very large galaxy surveys, the APM survey and the Edinburgh-Durham Southern Galaxy Catalogue (or COSMOS survey). These surveys can constrain the power on large scales of ≳ 10h −1 Mpc better than current redshift surveys, simply because such large numbers, ≳ 2 million galaxies to bJ ≤ 20.5, provide very high signal/noise in the estimated two-point correlation function for galaxies. Furthermore, the results for the three-dimensional galaxy two point correlation function, ξ(r), obtained from the measured projected function, ω(θ), should be quite robust for reasonable model number-redshift distributions, N(z), for these magnitude limits (see, e.g., Roche et al. 1993). Another clear advantage of measuring ω(θ) is that it is unaffected by the peculiar velocities of the galaxies, whereas they have an important effect on the corresponding ξ,(s) using galaxy redshift surveys.

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Xie, Jing, Xilan Luo, Jinfeng Wang i Yuyan Liu. "Effect of Inclined Orifice in Air Impingement Freezer on Heat Transfer Characteristics of Steel Strip Surface". Processes 11, nr 8 (10.08.2023): 2410. http://dx.doi.org/10.3390/pr11082410.

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In order to improve the heat transfer characteristics of the air impingement freezer, an impingement freezer experimental table was designed as the research object in this paper. Numerical simulation technology was used to simulate the impingement freezer experimental table on the basis of test verification. When the other structural parameters in the impingement freezer experimental table were constant, the effect of the inclination angle of the orifice plate (θ = 60°, 65°, 70°, 75°, 80°, 85°, and 90°) on the heat transfer characteristics of a steel strip surface was analyzed by two aspects, the average Nusselt number and the heat transfer uniformity. The results showed that with the increase in the inclination angle of the orifice plate (60° ≤ θ ≤ 90°), the average Nusselt number of the steel strip surface was increased by 19.39%, and the heat transfer uniformity index was decreased by 33.69%. When θ = 90°, the average Nusselt number on steel strip was the maximum, which was 263.68, and the heat transfer uniformity index was the minimum, which was 0.2039. Therefore, the heat transfer intensity and heat transfer uniformity in the air impingement freezer could be improved when the inclination angle of the orifice plates was 90°. This helps to improve the output of the air impingement freezer, reduce energy consumption, and improve the quality of frozen food.

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Kaman, Mete Onur. "Effect of fiber orientation on fracture toughness of laminated composite plates [0°/θ°]s". Engineering Fracture Mechanics 78, nr 13 (sierpień 2011): 2521–34. http://dx.doi.org/10.1016/j.engfracmech.2011.06.005.

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JO, JONG-HYUN, i YOUNG-SHIN LEE. "A STUDY OF RICOCHET PHENOMENON FOR INCLINED IMPACT OF PROJECTILE". International Journal of Modern Physics: Conference Series 06 (styczeń 2012): 443–48. http://dx.doi.org/10.1142/s2010194512003583.

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In this study, the numerical simulation using AUTODYN-3D program was investigated for trajectory prediction for inclined impacts of projectiles. The penetration and perforation of polycarbonate( PC ) plate by 7.62 mm projectile was investigated numerically. The characteristic structure of the projectile's trajectory in the PC plates was studied. Two combined failure criteria were used in the target plate, and the target plate was modeled with the properties of polycarbonate for simulating the ricochet phenomenon. The numerical analyses were used to study the effect of the angle of inclination on the trajectory and kinetic energy of the projectile. The dynamic deformation behaviors tests of PC were compared with numerical simulation results which can be used for predictive purpose. Ricochet phenomenon for angles of inclination of 0° ≤ θ ≤ 20° in the analysis. The projectile perforated the plate for θ > 30°, thus defined a failure envelope for numerical configuration. The numerical analyses was used to study the effect under the projectile impact velocity on the depth of penetration(DOP).

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Kumar, Dhotre Pavan, i Chikkol V. Srinivasa. "Modal Characterization of Sandwich Skew Plates". Acta Mechanica et Automatica 15, nr 3 (1.09.2021): 143–53. http://dx.doi.org/10.2478/ama-2021-0019.

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Abstract The current work focuses on the experimental and finite element free vibration studies of laminated composite sandwich skew plates. The comparison was made between the experimental values obtained by the Fast Fourier transform (FFT) analyzer and a finite element solution obtained from CQUAD8 finite element of The MacNeal-Schwendler Corporation (MSC) / NASA STRucture Analysis (NASTRAN) software. The influence of parameters such as aspect ratio (AR) (a/b), skew angle (α), edge condition, laminate stacking sequence, and fiber orientation angle (θ°) on the natural frequencies of sandwich skew plates was studied. The values obtained by both the finite element and experiment approaches are in good agreement. The natural frequencies increase with an increase in the skew angle for all given ARs.

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28

Ghanim, Mohannad R., i Sabah T. Ahmed. "Reducing Roof Solar Heat Gain by Using Double-Skin Ventilated Roofs". Engineering and Technology Journal 38, nr 3A (26.03.2020): 402–11. http://dx.doi.org/10.30684/etj.v38i3a.462.

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Double skin ventilated roof is one of the important passive cooling techniques to reduce solar heat gain through roofs. In this research, an experimental study was performed to investigate the thermal behaviour of a double skin roof model. The model was made of two parallel galvanized steel plates. Galvanized steel has been used in the roof construction of industrial buildings and storehouses in Iraq. The effect of inclination angle (ϴ) from the horizontal and the spacing (S) between the plates was investigated at different radiation intensities. It is found that using a double skin roof arrangement with a sufficient air gap (S) can reduce the heat gain significantly. The higher the inclination angle (ϴ) the higher the ventilation rate, the lower the heat gain through the roof. In this study, increasing the air gap from 2 cm to 4 cm reduced the heat gain significantly but when the gap was further increased to 6 cm, the reduction in the heat flux was insignificant. A dimensionless correlation was also reduced between Nusselt number () and the single parameter where L is the channel length. This correlation can be handily utilized for designing of engineering applications dealing with high temperature difference natural convection heat transfer.

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29

Kishi, Yoichi, Zenjiro Yajima, Teiko Okazaki, Yasubumi Furuya i Manfred Wuttig. "Magnetic Properties and Microstructures of Rapidly Solidified FePd Alloy Ribbons". Advances in Science and Technology 59 (wrzesień 2008): 24–29. http://dx.doi.org/10.4028/www.scientific.net/ast.59.24.

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It is well known that FePd alloys are effective as a magneto-thermoelastic actuator material, because they have large magnetostriction and shape memory effect. In order to use the alloys for a micro-actuator, magnetic properties and microstructures have been examined as for rapidly solidified Fe-29.6 at% Pd alloy ribbons. The ribbons exhibit a large magnetostriction at room temperature and good shape memory effect. Magnetostriction and coercive force of the ribbons markedly depend on the direction of the applied magnetic field. Maximum values of magnetostriction and coercive force are obtained at θ = 85 degree (θ is the angle between the magnetic field and the ribbon plane). Relief effects corresponding to the formation of FCT martensite variants are observed on the grains. X-ray diffraction profile at room temperature shows that FCT martensitic phase and FCC parent phase coexist in the ribbon. Dense striations are observed in the TEM bright field images of FCT martensite plates. Selected area electron diffraction patterns revealed the striations to be thin twins.

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30

KRYLOV, VICTOR V. "PROPAGATION OF LOCALIZED VIBRATION MODES ALONG EDGES OF IMMERSED WEDGE-LIKE STRUCTURES: GEOMETRICAL-ACOUSTICS APPROACH". Journal of Computational Acoustics 07, nr 01 (marzec 1999): 59–70. http://dx.doi.org/10.1142/s0218396x99000060.

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The theory of antisymmetric localized elastic modes propagating along edges of immersed wedge-like structures is developed using the geometrical-acoustics approach to the description of flexural waves in elastic plates of variable thickness. The velocities of these modes, often called wedge acoustic waves, are calculated using solutions of the dispersion equation of the Bohr-Sommerfeld type following from the geometrical-acoustics description of localized wedge modes. In a subsonic regime of wave propagation, i.e. for wedge modes slower than sound in liquid, the influence of liquid loading results in significant decrease of wedge wave velocities in comparison with their values in vacuum. This decrease is a nonlinear function of a wedge apex angle θ and is more pronounced for small values of θ. In a supersonic regime of wedge wave propagation, a smaller decrease in velocities takes place and the waves travel with the attenuation due to radiation of sound into the surrounding liquid. The comparison is given with the recent experimental investigations of wedge waves carried out by independent researchers.

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31

Infante, Leopoldo. "A New Catalogue of Faint Galaxies". Symposium - International Astronomical Union 139 (1990): 369–70. http://dx.doi.org/10.1017/s0074180900240941.

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A new catalogue of faint galaxies on a 3 deg2 area near the North Galactic Pole (NGP), complete to J =24.5 and F =23.5, has been obtained from nine Canada France Hawaii Telescope prime focus plates. The angular correlation function has been measured for the first time to separations ~1°. Preliminary results indicate a power law slope of ≈ −0.8 at small separations and no sharp break for θ ≤ 1°. We also find some evidence that the power law slope flattens to fainter limiting magnitudes.

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32

Abu-Farsakh, Ghazi A., Amin H. Almasri i Dana H. Qa’dan. "Stress concentration around a central hole as affected by material nonlinearity in fibrous composite laminated plates subject to in-plane loading". Science and Engineering of Composite Materials 22, nr 1 (1.01.2015): 31–36. http://dx.doi.org/10.1515/secm-2013-0125.

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AbstractThe distribution of stresses in laminated composite plates with a central circular hole and having various stacking sequences, different geometric dimensions and subjected to in-plane axial tensile loading was investigated. The ANSYS computer program was utilized using the finite element method to study the linear and nonlinear material effects. A new method was proposed for the purpose of incorporating the material nonlinearity model into the ANSYS computer program using the secant modulus material model. The aim of the authors is to analyze the effect of D/b and a/b ratios (where D is hole diameter, b is plate width, and a is plate length) on stresses induced in such plates. Analysis was carried out for angle-ply, four-layered symmetric laminated rectangular plates with various stacking sequences [±θ]s.

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33

Ma, Nailin, Yanjun Sun i Yongjun Jian. "Electromagnetohydrodynamic (EMHD) Flow in a Microchannel with Random Surface Roughness". Micromachines 14, nr 8 (16.08.2023): 1617. http://dx.doi.org/10.3390/mi14081617.

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This study investigates the effect of small random transverse wall roughness on electromagnetohydrodynamic (EMHD) flow is in a microchannel, employing the perturbation method based upon stationary random function theory. An exact solution of a random corrugation function ξ, which is a measure of the flow rate deviated from the case without the roughness of two plates, is obtained by integrating the spectral density. After the sinusoidal, triangular, rectangular, and sawtooth functions that satisfy the Dirichlet condition are expanded into the Fourier sine series, the spectral density of the sine function is used to represent the corrugation function. Interestingly, for sinusoidal roughness, the final expression of the corrugation function is in good agreement with our previous work. Results show that no matter the shape of the wall roughness, the flow rate always decreases due to the existence of wall corrugation. Variations of the corrugation function and the flow rate strongly depend on fluid wavenumber λ and Hartmann number Ha. Finally, the flow resistance is found to become small, and the flow rate increases with roughness that is in phase (θ = 0) compared with the one that is out of phase (θ = π).

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34

Loughlan, J. "The compressive buckling performance of anti-symmetric composite laminates and the effect on behaviour of membrane-flexural coupling". Aeronautical Journal 106, nr 1065 (listopad 2002): 595–606. http://dx.doi.org/10.1017/s000192400001825x.

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AbstractThe compressive stability of anti-symmetric angle-ply laminated plates with particular reference to the degrading influence of membrane-flexural coupling is reported in this paper. A specific configuration of anti-symmetric laminate is dealt with in the paper and this takes the form [θ/-θ]n whereby 2n is the total number of plies in the laminated stack. With regard to compressive buckling the paper gives an indication that anti-symmetric laminates with 8 plies or more will yield performance levels which are almost identical to their symmetric counterparts. The degree of membrane-flexural coupling in the laminated composite plates is varied, essentially, by changing the ply angle and also by altering the number of plies in the laminated stack, for a given composite material system. The coupled compressive buckling solutions are determined using the finite strip method of analysis. In order to provide an adequate level of flexibility in the analysis procedure and to ensure a high level of accuracy of solution, the buckling displacement fields of the strip formulation are those which are described in a multi-term form.Results are given for anti-symmetric angle-ply laminated plates subjected to uniaxial and biaxial compression and these have been obtained from fully converged finite strip structural models. Validation of the finite strip formulation is indicated in the paper through comparisons with exact solutions where appropriate. The natural half-wavelength of the compressive buckling mode of the composite plates is shown to be significantly influenced by variation in the ply angle. Increasing the number of plies in the laminated system is seen to reduce the degree of coupling and the critical stress levels are noted to tend towards the plate orthotropic solutions. The ply angle corresponding to the optimised, compressive buckling stress for any particular laminate is noted in the paper to be influenced by the support boundary conditions at the plates unloaded edges.

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35

Loughlan, J. "The compressive buckling performance of anti-symmetric composite laminates and the effect on behaviour of membrane-flexural coupling". Aeronautical Journal 106, nr 1065 (listopad 2002): 595–606. http://dx.doi.org/10.1017/s000192400001160x.

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AbstractThe compressive stability of anti-symmetric angle-ply laminated plates with particular reference to the degrading influence of membrane-flexural coupling is reported in this paper. A specific configuration of anti-symmetric laminate is dealt with in the paper and this takes the form [θ/-θ]n whereby 2n is the total number of plies in the laminated stack. With regard to compressive buckling the paper gives an indication that anti-symmetric laminates with 8 plies or more will yield performance levels which are almost identical to their symmetric counterparts. The degree of membrane-flexural coupling in the laminated composite plates is varied, essentially, by changing the ply angle and also by altering the number of plies in the laminated stack, for a given composite material system. The coupled compressive buckling solutions are determined using the finite strip method of analysis. In order to provide an adequate level of flexibility in the analysis procedure and to ensure a high level of accuracy of solution, the buckling displacement fields of the strip formulation are those which are described in a multi-term form.Results are given for anti-symmetric angle-ply laminated plates subjected to uniaxial and biaxial compression and these have been obtained from fully converged finite strip structural models. Validation of the finite strip formulation is indicated in the paper through comparisons with exact solutions where appropriate. The natural half-wavelength of the compressive buckling mode of the composite plates is shown to be significantly influenced by variation in the ply angle. Increasing the number of plies in the laminated system is seen to reduce the degree of coupling and the critical stress levels are noted to tend towards the plate orthotropic solutions. The ply angle corresponding to the optimised, compressive buckling stress for any particular laminate is noted in the paper to be influenced by the support boundary conditions at the plates unloaded edges.

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36

Nitsche, Ludwig C., i E. J. Hinch. "Shear-induced lateral migration of Brownian rigid rods in parabolic channel flow". Journal of Fluid Mechanics 332 (luty 1997): 1–21. http://dx.doi.org/10.1017/s0022112096003369.

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This paper addresses the cross-stream migration of rigid rods undergoing diffusion and advection in parabolic flow between flat plates – a simple model of a polymer that possesses internal (rotational) degrees of freedom for which the probability distribution depends upon the local shear rate. Unequivocal results on the observable concentration profiles across the channel are obtained from a finite–difference solution of the full Fokker–Planck equation in the space of lateral position y and azimuthal angle φ, the polar angle θ being constrained to π/2 for simplicity. Steric confinement and hydrodynamic wall effects, operative within thin boundary layers, are neglected. These calculations indicate that rods should migrate toward the walls. For widely separated rotational and translational timescales asymptotic analysis gives effective transport coefficients for this migration. Based upon angular distributions at arbitrary rotational Péclet number – obtained here by a least–squares collocation method using trigonometric basis functions – accumulation at the walls is confirmed quantitatively by the effective transport coefficients. The results are extended to free rotation using spherical harmonics as the basis functions in the (φ, θ) orientation space. Finally, a critique is given of the traditional thermodynamic arguments for polymer migration as they would apply to purely rotational internal degrees of freedom.

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37

Arslan, Nurettin, Mehmet Çelik i Nuray Arslan. "Prediction of the elastic–plastic behavior of thermoplastic composite laminated plates ([0°/θ°]2) with square hole". Composite Structures 55, nr 1 (styczeń 2002): 37–49. http://dx.doi.org/10.1016/s0263-8223(01)00126-x.

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Karayiannis, T. G., i J. D. Tarasuk. "Natural Convection in an Inclined Rectangular Cavity With Different Thermal Boundary Conditions at the Top Plate". Journal of Heat Transfer 110, nr 2 (1.05.1988): 350–57. http://dx.doi.org/10.1115/1.3250491.

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Natural convection inside a rectangular cavity with different temperature boundary conditions on the cold top plate was studied using a Mach-Zehnder interferometer for θ = 15, 45, and 60 deg to the horizontal. At θ = 60 deg coupling with external forced convection and non-coupled heat transfer from a cavity with an isothermal top plate was studied. In all experiments the bottom hot plate was isothermal. The Rayleigh number Ra was varied from subcritical to 6×105 and the cavity aspect ratio ARx, from 6.68 to 33.4. The Reynolds number of the external forced flow Redh was constant and approximately equal to 5.8×104. It was found that for Ra ≲ 3×104 the differing thermal boundary conditions at the top plate did not affect the local or average heat transfer rates from the cavity. For Ra ≳ 3×104 coupling at the top plate compared to the non-coupled case resulted not only in a reduction in the variation of the local heat transfer rates at the cold plate, but also in a significant reduction in the variation of the average transfer rates from hot and cold plates of the cavity. Forced convection at the top plate as compared to natural convection resulted only in a small reduction in the heat transfer coefficient at the cold plate. Correlation equations for coupled and noncoupled average heat transfer rates are presented.

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39

Vu, M. N., S. Geniaut, P. Massin i J. J. Marigo. "Numerical investigation on corner singularities in cracked plates using the G-theta method with an adapted θ field". Theoretical and Applied Fracture Mechanics 77 (czerwiec 2015): 59–68. http://dx.doi.org/10.1016/j.tafmec.2015.02.003.

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40

Burak Toparli, M., i Michael E. Fitzpatrick. "Through Thickness Residual Stress Measurements by Neutron Diffraction and Hole Drilling in a Single Laser-Peened Spot on a Thin Aluminium Plate". Materials Science Forum 772 (listopad 2013): 167–72. http://dx.doi.org/10.4028/www.scientific.net/msf.772.167.

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Residual stress measurements are very challenging in thin aluminium plates. Rolling-induced crystallographic texture can lead to an S-shape fit when using the sin2ψ method for surface X-ray diffraction. Peak broadening and missing peaks can also be observed for synchrotron X-ray diffraction with conventional θ/2θ scanning due to texture. In addition, when measuring near the plate surfaces, partially-filled gauge volumes in diffraction experiments will lead to “pseudo-strains”, an apparent shift between measured and actual positions for the diffraction peak. Obtaining a meaningful value of d0 for strain calculations is another issue for diffraction experiments in thin plates. The low thickness also offers challenges for destructive methods including incremental hole drilling, i.e. there is no defined ASTM standard for measuring non-uniform residual stress profile for thin plates. In this work, 2-mm-thick Al2024-T351 plate was investigated for residual stress fields due to laser peening. Neutron diffraction measurements were carried out at POLDI (Pulse Overlap time-of-flight Diffractometer) in PSI, Switzerland and the results are compared with incremental hole drilling.

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41

SHISHKINA, OLGA, i ANDRÉ THESS. "Mean temperature profiles in turbulent Rayleigh–Bénard convection of water". Journal of Fluid Mechanics 633 (25.08.2009): 449–60. http://dx.doi.org/10.1017/s0022112009990528.

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We report an investigation of temperature profiles in turbulent Rayleigh–Bénard convection of water based on direct numerical simulations (DNS) for a cylindrical cell with unit aspect ratio for the same Prandtl number Pr and similar Rayleigh numbers Ra as used in recent high-precision measurements by Funfschilling et al. (J. Fluid Mech., vol. 536, 2005, p. 145). The Nusselt numbers Nu computed for Pr = 4.38 and Ra = 108, 3 × 108, 5 × 108, 8 × 108 and 109 are found to be in excellent agreement with the experimental data corrected for finite thermal conductivity of the walls. Based on this successful validation of the numerical approach, the DNS data are used to extract vertical profiles of the mean temperature. We find that near the heating and cooling plates the non-dimensional temperature profiles Θ(y) (where y is the non-dimensional vertical coordinate), obey neither a logarithmic nor a power law. Moreover, we demonstrate that the Prandtl–Blasius boundary layer theory cannot predict the shape of the temperature profile with an error less than 7.9% within the thermal boundary layers (TBLs). We further show that the profiles can be approximated by a universal stretched exponential of the form Θ(y) ≈ 1 − exp(−y − 0.5y2) with an absolute error less than 1.1% within the TBLs and 5.5% in the whole Rayleigh cell. Finally, we provide more accurate analytical approximations of the profiles involving higher order polynomials in the approximation.

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42

Kamal Babu, Karupannan, Kavan Panneerselvam, Paulraj Sathiya, Abdul Haq Noorul Haq, Srinivasan Sundarrajan, Potta Mastanaiah i Chunduri Venkata Srinivasa Murthy. "Effects of various tool pin profiles on mechanical and metallurgical properties of friction stir welded joints of cryorolled AA2219 aluminium alloy". Metallurgical Research & Technology 115, nr 2 (2018): 212. http://dx.doi.org/10.1051/metal/2017100.

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Friction stir welding (FSW) process was conducted on cryorolled (CR) AA2219 plate using different tool pin profiles such as cylindrical pin, threaded cylindrical pin, square pin and hexagonal pin profiles. The FSW was carried out with pairs of 6 mm thick CR aluminium plates with different tool pin profiles. The different tool pin profile weld portions' behaviors like mechanical (tensile strength, impact and hardness) and metallurgical characteristics were analyzed. The results of the mechanical analysis revealed that the joint made by the hexagonal pin tool had good strength compared to other pin profiles. This was due to the pulsating action and material flow of the tool resulting in dynamic recrystallization in the weld zone. This was confirmed by the ultra fine grain structure formation in Weld Nugget (WN) of hexagonal pin tool joint with a higher percentage of precipitate dissolution. The fractograph of the hexagonal tool pin weld portion confirmed the finer dimple structure morphology without having any interior defect compared to other tool pin profiles. The lowest weld joint strength was obtained from cylindrical pin profile weld joint due to insufficient material flow during welding. The Transmission Electron Microscope and EDX analysis showed the dissolution of the metastable θ″, θ′ (Al2Cu) partial precipitates in the WN and proved the influence of metastable precipitates on enhancement of mechanical behavior of weld. The XRD results also confirmed the Al2Cu precipitation dissolution in the weld zone.

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Yu, Wei, Ju Long Yuan, Bing Hai Lv, Qian Fa Deng i Dun Liu. "Analysis on Sliding State of Ball in Rotated Dual-Plates Lapping Mode". Advanced Materials Research 317-319 (sierpień 2011): 345–49. http://dx.doi.org/10.4028/www.scientific.net/amr.317-319.345.

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Abstract . The sliding states of precision ball is an important factor in lapping uniform. To study the sliding state of ball in Rotated Dual-Plates(RDP) Lapping Mode, this paper analyses several kinds of sliding states from theory to the simulation based on the kinematics and dynamic.It is assumed that the slide could occure between the ball and inner lower plate or between the ball and outer lower plate. The simulation results show that there are several numerical combination among the spin angle θ, the coefficient ratio of sliding friction and the rotating speed ratio of the outer lower plate and inner plate,which is beneficial or adverse to improve the lapping uniformity.The results also show Machining load and the friction coefficient is increased, the critical speed of lapping plate also is higher, the ball is more not easy slide,and the critical speed of slide could be obtained to direct processing.

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44

Arslan, Nurettin, M. Onur Kaman i Mehmet Duranay. "Elastic–Plastic Stress Analysis in Aluminum Metal–Matrix Composite-laminated Plates ([0°/θ°]2) Under Transverse Uniformly Distributed Load". Journal of Reinforced Plastics and Composites 23, nr 18 (grudzień 2004): 2025–45. http://dx.doi.org/10.1177/0731684404041710.

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Lie-heng, Wang. "Mathematical model of coupled plates meeting at an angle 0 < θ < π and its finite element method". Numerical Methods for Partial Differential Equations 9, nr 1 (styczeń 1993): 13–22. http://dx.doi.org/10.1002/num.1690090103.

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Gangadharan, Sathya N., i Heinz L. Krein. "Jet-Propelled Remote-Operated Underwater Vehicles Guided by Tilting Nozzles". Marine Technology and SNAME News 26, nr 02 (1.04.1989): 131–44. http://dx.doi.org/10.5957/mt1.1989.26.2.131.

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This paper is a study and experimental analysis of a forced jet propulsion system with tilting-type nozzles for slow-moving remotely operated underwater vehicles (ROV's). A test setup simulating the motion of the underwater vehicle was fabricated to investigate the effect of nozzle configurations on the propulsion of such vehicles. Plexiglass nozzles of different conical contraction angles (θ = 4 to 28 deg), different conical expansion angles (θ = 3 to 9 deg), and a straight cylindrical section were used in the study. Tests were carried out underwater, and the parameters measured include thrust, flow rate, angular velocity, and total head. Different circular disk type drag plates were used to simulate the drag of the vehicle underwater. Efficiency of propulsion is the criterion for comparing the performance of each nozzle. An expression for the optimum efficiency was derived neglecting the effect of inlet head recovery, which can be assumed for slow-moving vehicles. The energy loss and loss coefficients in submerged propulsion nozzles were found both theoretically and experimentally. A proposal for the fabrication and testing of an innovative design of a jet-propelled ROV guided by tilting nozzles is presented. The design uses a stepper motor for tilting the nozzles. A comparison is made between stationary and swivel-type configurations. The nozzles were tested for optimum area ratio. The propulsion system and the ROV was designed and checked for stability. The study revealed that for a range of flow rates, one particular nozzle was the most efficient compared to other nozzles.

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Gazizov, Marat, Ivan Zuiko i Rustam Kaibyshev. "Effect of Plastic Deformation on a Dispersion of Omega-Phase and Mechanical Properties of an Al-Cu-Mg-Ag Alloy". Advanced Materials Research 922 (maj 2014): 189–94. http://dx.doi.org/10.4028/www.scientific.net/amr.922.189.

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Effect of cold rolling prior to ageing on a dispersion of secondary phases and mechanical properties at room temperature for an Al-5.6Cu-0.72Mg-0.5Ag-0.32Mn-0.17Sc-0.12Zr (wt. %) alloy, which was solution treated and water quenched initially, was examined. It was shown that cold working leads to significant increase in density of lattice dislocations that induces the formation discrete agglomerates of the θ′-phase on the {100} planes. Strain of 7% provided increased aspect ratio (length to thickness) of plates that leads to moderate increase of strength. Imposing of higher strains leads to increased lattice dislocation density and the formation of deformation-induced boundaries. Precipitation of the coarse particles of secondary phases on these boundaries takes place. The high yield stress (YS) of 535 MPa and ultimate tensile strength (UTS) of 570 MPa, were attained after cold rolling with a reduction of 80% followed by ageing at 190°C for 2 h. The effect of plastic deformation prior to ageing on the precipitation behavior and strengthening of Al-Cu-Mg-Ag alloy is discussed.

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Chhorn, Buntheng, i WooYoung Jung. "A Parametric Study on the Elliptical hole Effects of Laminate Composite Plates under Thermal Buckling Load". Science and Engineering of Composite Materials 27, nr 1 (25.06.2020): 196–203. http://dx.doi.org/10.1515/secm-2020-0019.

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AbstractIn this study, a thermal buckling analysis of laminate composite square plate was performed with elliptical hole cutout using the finite element method. Graphite/Epoxy laminate plate used in this study is symmetrical stacking sequence plate [(0/90)2]s. This laminate square plate was subjected to temperature loading with clamped support on all edges. Moreover, the parameters considered were fiber orientation (θ), a/b ratio (elliptical hole), elliptical hole inclination (φ), thermal expansion coefficient ratio (α1/α2), and thickness of plates (t). The results showed that as the thermal expansion coefficient ratio changes, the elliptical hole ratio and the elliptical hole inclination have inconsequential effects on the performance of the resistance of laminate composite plates. The maximum values of thermal buckling amplification factor were obtained when the ratio a/b = 1.0, which is a circle cutout,while the minimum values were obtained when the ratio a/b = 0.5, regardless of the thickness of plates. Moreover, the plate with elliptical or circle cutout hole provides about 4% to 9% higher buckling resistance than that of the plate without hole cutout, because when subjected to temperature loading the plate with hole can release stress better than the plate without hole.

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Chhorn, Buntheng, i WooYoung Jung. "Effects of Elliptical Hole on the Correlation of Natural Frequency with Buckling Load of Basalt Laminates Composite Plates". Science and Engineering of Composite Materials 27, nr 1 (11.07.2020): 216–25. http://dx.doi.org/10.1515/secm-2020-0021.

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AbstractRecently, basalt fiber reinforced polymer (BFRP) is acknowledged as an outstanding material for the strengthening of existing concrete structure, especially it was being used in marine vehicles, aerospace, automotive and nuclear engineering. Most of the structures were subjected to severe dynamic loading during their service life that may induce vibration of the structures. However, free vibration studied on the basalt laminates composite plates with elliptical cut-out and correlation of natural frequency with buckling load has been very limited. Therefore, effects of the elliptical hole on the natural frequency of basalt/epoxy composite plates was performed in this study. Effects of stacking sequence (θ), elliptical hole inclination (ϕ), hole geometric ratio (a/b) and position of the elliptical hole were considered. The numerical modeling of free vibration analysis was based on the mechanical properties of BFRP obtained from the experiment. The natural frequencies as well as mode shapes of basalt laminates composite plates were numerically determined using the commercial program software (ABAQUS). Then, the determination of correlation of natural frequencies with buckling load was carried out. Results showed that elliptical hole inclination and fiber orientation angle induced the inverse proportion between natural frequency and buckling load.

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Zeng, Y., i S. Weinbaum. "Stokes problems for moving half-planes". Journal of Fluid Mechanics 287 (25.03.1995): 59–74. http://dx.doi.org/10.1017/s0022112095000851.

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New exact solutions of the Navier–Stokes equations are obtained for the unbounded and bounded oscillatory and impulsive tangential edgewise motion of touching half-infinite plates in their own plane. In contrast to Stokes classical solutions for the harmonic and impulsive motion of an infinite plane wall, where the solutions are separable or have a simple similarity form, the present solutions have a two-dimensional structure in the near region of the contact between the half-infinite plates. Nevertheless, it is possible to obtain relatively simple closed-form solutions for the flow field in each case by defining new variables which greatly simplify the r- and θ-dependence of the solutions in the vicinity of the contact region. These solutions for flow in a half-infinite space are then extended to bounded flows in a channel using an image superposition technique. The impulsive motion has application to the motion near geophysical faults, whereas the oscillatory motion has arisen in the design of a novel oscillating half-plate flow chamber for examining the effect of fluid shear stress on cultured cell monolayers.

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