Journal articles: 'Geometrical influences'

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Javed, Saira, F. H. H. Al Mukahal, and S. B. A. El Sayed. "Geometrical Influences on the Vibration of Layered Plates." Shock and Vibration 2021 (January 15, 2021): 1–17. http://dx.doi.org/10.1155/2021/8843358.

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This paper aims to study the influence of different geometric properties and support conditions on the vibration of layered plates of nonuniform thickness under shear deformation theory. The layered plates are supposed to have arbitrarily nonuniform thickness as linear, exponential, and sinusoidal. The spline approximation is used to approximate translational and angular displacement functions. Eigen frequency parameters are calculated by solving eigenvalue problem. The geometrical influences such as number of lay-ups, different ply orientations, each ply consisting of different material, side-to-thickness ratio, and aspect ratio are taken into consideration to examine the frequency variation of plates for two different support conditions.

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Edwardson, S. P., E. Abed, K. Bartkowiak, G. Dearden, and K. G. Watkins. "Geometrical influences on multi-pass laser forming." Journal of Physics D: Applied Physics 39, no. 2 (January 6, 2006): 382–89. http://dx.doi.org/10.1088/0022-3727/39/2/021.

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Kruger, S. E., C. C. Hegna, and J. D. Callen. "Geometrical influences on neoclassical magnetohydrodynamic tearing modes." Physics of Plasmas 5, no. 2 (February 1998): 455–60. http://dx.doi.org/10.1063/1.872738.

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Korolev, Albert V., Andrei F. Balayev, and Boris M. Iznairov. "Relaxation of Residual Stresses in Bearing Rings Based on the Optimal Geometric Setup of Equipment for Centerless Running." Materials Science Forum 973 (November 2019): 183–88. http://dx.doi.org/10.4028/www.scientific.net/msf.973.183.

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This paper discusses the technological method of residual stress relaxation of bearing rings by centerless running with cylindrical rolls. Described a new approach to relieve residual stresses by centerless running of elastically-deforming rolls on the basis of the geometrical setup of the equipment. It was found that geometrical setup of the equipment influences an elastic strain of parts and the degree of residual stress relaxation. We obtained a mathematical model for calculation of setup parameters to ensure the required variation value of elastic strain of the part. The results of experiments confirm the influence of the geometric setup on the magnitude of residual stress relaxation.

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Ruf, A., P. Berger, F. Dausinger, and H. Hügel. "Analytical investigations on geometrical influences on laser drilling." Journal of Physics D: Applied Physics 34, no. 18 (September 5, 2001): 2918–25. http://dx.doi.org/10.1088/0022-3727/34/18/327.

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Jiang, Yong Jun. "Statistical Tolerance Analysis Based on Constraint Satisfaction Problems and Monte Carlo Simulation." Advanced Materials Research 433-440 (January 2012): 6616–21. http://dx.doi.org/10.4028/www.scientific.net/amr.433-440.6616.

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This paper deals with the mathematical formulation of tolerance analysis. The mathematical formulation presented simulates the influences of geometrical deviations on the geometrical behavior of the mechanism, and integrates the quantifier notion. We propose a mathematical formulation of tolerance analysis which simulates the influences of geometrical deviations on the geometrical behavior of the mechanism, and integrates the quantifier notion. To compute this mathematical formulation, two approaches based on Quantified Constraint Satisfaction Problem solvers and Monte Carlo simulation are proposed and tested.

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Fan, Yu Feng, Yong Jian Zhu, and Shao Hui Yin. "Optimum Geometrical Arrangement of Workpiece in the Ultrasonic Vibration Shoe Centerless Grinding." Advanced Materials Research 97-101 (March 2010): 4100–4105. http://dx.doi.org/10.4028/www.scientific.net/amr.97-101.4100.

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This paper clarifies the influence of the geometrical arrangement of the workpiece on workpiece roundness in the ultrasonic elliptic-vibration shoe centerless grinding, and determines an optimum geometrical arrangement for minimizing the roundness error of the workpiece. The influences of the geometrical arrangements of the workpiece on workpiece roundness were investigated by computer simulation and practical grinding operations involving pin shaped workpieces. The experimental results agreed closely with those obtained by the simulation, the results of simulation and grinding tests indicated that the final roundness error of the workpiece after grinding reaches a minimum at a particular angle number (= + =7) for various values of the blade angle.

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Noh, Sam Young, and Sang Yun Lee. "Structural Behaviour Evaluation of Natural Draught Cooling Towers under the Consideration of Shell-Geometric Parameters." Applied Mechanics and Materials 284-287 (January 2013): 1396–400. http://dx.doi.org/10.4028/www.scientific.net/amm.284-287.1396.

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In the design procedure of the cooling tower the form-finding of the shell is the most important process, because the shape of the shell determines the sensitivity of dynamic behavior of the whole tower against wind excitation. The purpose of the study is the investigation of the influences of the geometric parameters of the cooling tower shell on the structural behavior. The geometric parameters - height of throat, angle of base lintel and radius of top lintel - were analyzed in detail. In the linear analysis the influence of each geometrical parameter will be evaluated by the required amount of the reinforcement steel. The realistic behaviours of the towers with various geometries, found out by geometrically and physically non-linear analysis, will be discussed in detail. Each geometry parameter influence will be evaluated by the comparison of the damage index developments in the tower under increasing wind effect. Herein a damage indicator is defined by means of the modal parameters; natural frequencies and mode shapes varying according to the damage state. As a result, a hyperbolic rotational shell with the small radius overall will yield the shell geometry with a higher first natural frequency and thus a wind-insensitive structure. Linearly and nonlinearly numerical simulations demonstrate influence of the shell-geometric parameters on structural behaviours. The results of this study may be informative for the form-finding of the cooling tower shell.

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du Plessis, J. P. "Geometrical Models for Porous Membrane Morphologies." Water Science and Technology 25, no. 10 (May 1, 1992): 363–72. http://dx.doi.org/10.2166/wst.1992.0262.

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The dual goal of the analysis is the development of a microstructural geometric and micro-flow model for the investigation of membrane characteristics as well as for use in numerical simulation of macro-flow phenomena in membrane technology- Membrane structures suggest a composition of different porous regimes of vastly different microstructures and some basic types of porous media are therefore discussed, emphasizing their different influences on a traversing fluid. Incorporation of the different models into a general momentum transport equation, fit for numerical computation of membrane systems, is discussed.

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Liu, Xueshu, Yuxing Yang, Li Huang, Ping Zhang, and Hang Gao. "Numerical Analysis of the Influences of Geometrical Deviation on Delamination in Composite Laminates around the Countersunk Hole." International Journal of Aerospace Engineering 2018 (2018): 1–11. http://dx.doi.org/10.1155/2018/5061948.

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During countersunk hole machining, defects like geometrical deviation of the chamfer angle and delamination are easily introduced into the structure. To investigate the influences of geometrical deviation on delamination propagation around the countersunk hole during assembly, a progressive damage model (PDM) combining cohesive element was proposed and validated. Numerical analyses were then carried out to study delamination propagation behavior under the influences of geometrical parameters including delamination factor, chamfer angle, and location of delamination. The results show that when delamination appears at the transition area of the countersunk hole, the load causing the delamination evolution is much smaller than other cases.

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Phuong, Nguyen Thi, Vu Hoai Nam, Nguyen Thoi Trung, Vu Minh Duc, and Pham Van Phong. "Nonlinear Stability of Sandwich Functionally Graded Cylindrical Shells with Stiffeners Under Axial Compression in Thermal Environment." International Journal of Structural Stability and Dynamics 19, no. 07 (June 26, 2019): 1950073. http://dx.doi.org/10.1142/s0219455419500731.

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The geometrically nonlinear response of sandwich functionally graded cylindrical shells reinforced by orthogonal and/or spiral stiffeners and subjected to axial compressive loads is investigated in this paper. Two types of sandwich functionally graded material models are considered. The formulations are based on the Donnell shell theory considering geometrical nonlinearity and Pasternak’s elastic foundation. The improved Lekhnitskii’s smeared stiffener technique is used to account for the stiffener effects with both mechanical and thermal stresses. The results obtained indicate that the spiral stiffeners have significantly beneficial influences in comparison with orthogonal stiffeners on the nonlinear buckling behavior of shells. The relatively large effects of temperature change, geometrical and material parameters are also demonstrated in the numerical investigations.

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Giordana, S., S. J. Sherwin, J. Peiró, D. J. Doorly, J. S. Crane, K. E. Lee, N. J. W. Cheshire, and C. G. Caro. "Local and Global Geometric Influence on Steady Flow in Distal Anastomoses of Peripheral Bypass Grafts." Journal of Biomechanical Engineering 127, no. 7 (June 15, 2005): 1087–98. http://dx.doi.org/10.1115/1.2073507.

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We consider the effect of geometrical configuration on the steady flow field of representative geometries from an in vivo anatomical data set of end-to-side distal anastomoses constructed as part of a peripheral bypass graft. Using a geometrical classification technique, we select the anastomoses of three representative patients according to the angle between the graft and proximal host vessels (GPA) and the planarity of the anastomotic configuration. The geometries considered include two surgically tunneled grafts with shallow GPAs which are relatively planar but have different lumen characteristics, one case exhibiting a local restriction at the perianastomotic graft and proximal host whilst the other case has a relatively uniform cross section. The third case is nonplanar and characterized by a wide GPA resulting from the graft being constructed superficially from an in situ vein. In all three models the same peripheral resistance was imposed at the computational outflows of the distal and proximal host vessels and this condition, combined with the effect of the anastomotic geometry, has been observed to reasonably reproduce the in vivo flow split. By analyzing the flow fields we demonstrate how the local and global geometric characteristics influences the distribution of wall shear stress and the steady transport of fluid particles. Specifically, in vessels that have a global geometric characteristic we observe that the wall shear stress depends on large scale geometrical factors, e.g., the curvature and planarity of blood vessels. In contrast, the wall shear stress distribution and local mixing is significantly influenced by morphology and location of restrictions, particular when there is a shallow GPA. A combination of local and global effects are also possible as demonstrated in our third study of an anastomosis with a larger GPA. These relatively simple observations highlight the need to distinguish between local and global geometric influences for a given reconstruction. We further present the geometrical evolution of the anastomoses over a series of follow-up studies and observe how the lumen progresses towards the faster bulk flow of the velocity in the original geometry. This mechanism is consistent with the luminal changes in recirculation regions that experience low wall shear stress. In the shallow GPA anastomoses the proximal part of the native host vessel occludes or stenoses earlier than in the case with wide GPA. A potential contribution to this behavior is suggested by the stronger mixing that characterizes anastomoses with large GPA.

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13

Dao-ming, Lu. "Influences of Detuning on Geometrical Quantum Discord in Coupled Cavities System." International Journal of Theoretical Physics 56, no. 5 (January 24, 2017): 1440–48. http://dx.doi.org/10.1007/s10773-017-3284-z.

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14

Xu, R., D. X. Li, J. P. Jiang, and W. Liu. "Nonlinear Vibration Analysis of Membrane SAR Antenna Structure Adopting a Vector Form Intrinsic Finite Element." Journal of Mechanics 31, no. 3 (January 23, 2015): 269–77. http://dx.doi.org/10.1017/jmech.2014.97.

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ABSTRACTThis study adopted the Vector Form Intrinsic Finite Element (VFIFE) method to study the nonlinear vibration of the membrane SAR (Synthetic Aperture Radar) antenna structure. As the dynamic characteristic of the antenna is mainly determined by the support frame, it can be simplified as an axially loaded cantilever beam. The linear and geometrically nonlinear models of the axially loaded cantilever beam are established. The beam is modeled as discrete mass points which are connected by deformable elements through VFIFE method. A statics analysis is first presented to verify the VFIFE method. Then effects of the geometrical nonlinearity and axial load are investigated. It is believed that the presented study is valuable for better understanding the influences of the geometrical nonlinearity and axial load of the cantilever beam on the structural vibration characteristics.

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Ramesh Sagar, Vaishak, Kristina Wärmefjord, and Rikard Söderberg. "Effect of selective laser heat treatment on geometrical variation in boron steel components: An experimental investigation." Proceedings of the Institution of Mechanical Engineers, Part B: Journal of Engineering Manufacture 235, no. 1-2 (August 20, 2020): 54–64. http://dx.doi.org/10.1177/0954405420949759.

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Selective laser heat treatment is a well-known process for its ability to produce tailor heat treated blanks (THTB). Specifically, ultra high strength boron steels with tailored material properties can be produced. However, this process generates unwanted distortion and influences geometrical variation. This in turn can affect functionality, aesthetics, and performance of the final product. Understanding the effects on geometrical variation in the final product or the assembly will enable in designing and producing geometry assured products. In this paper, boron steel blanks were selectively laser heat treated with a specific heat treatment pattern and laser heating direction sequence. These heat treated blanks were then cold formed. Further on, spot welding simulation of the cold formed parts was performed to assess the effect on geometrical variation at the assembly level. The results show that the effect of selective laser heat treatment on geometrical variation at part level propagates further to the assembly level. It implies that the effect on geometrical variation should be minimized at part level, when the blanks are laser heat treated. Hence, the sources that influence geometrical variation at part level when employing selective laser heat treatment are presented and discussed. The motivation and possibilities to minimize the effects in the early design concept stages is provided.

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Zadpoor, Amir A. "Bone tissue regeneration: the role of scaffold geometry." Biomaterials Science 3, no. 2 (2015): 231–45. http://dx.doi.org/10.1039/c4bm00291a.

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Luo, X. Y., W. G. Li, and J. Li. "Geometrical Stress-Reducing Factors in the Anisotropic Porcine Heart Valves." Journal of Biomechanical Engineering 125, no. 5 (October 1, 2003): 735–44. http://dx.doi.org/10.1115/1.1614821.

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This study carries out a detailed parameter study based on a nonlinear anisotropic finite-element model published previously. The aim of this study is to identify the stress-reducing influences from geometrical parameters such as stent height, valve diameter, and the nonuniform thickness of porcine aortic valves under static loading condition. The anisotropy of the valve is considered to be transversely isotropic with fibers oriented along the circumferential directions, which enables us to use a simple anisotropic constitutive model using uniaxial experimental data. The results showed that in general, higher stent height and smaller diameter combined with nonuniform thickness give rise to a much more reduced overall stress level. Although the absolute values of the peak stresses may be influenced by the detailed orientations of fibers, the trends of the stress variation with the geometrical factors seem to be qualitatively consistent within the parameter ranges considered.

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Ge, Pei Pei, and Gui Lan Yu. "Vibration Propagation Characteristics of Binary Periodic Sandwich Panels." Applied Mechanics and Materials 226-228 (November 2012): 172–75. http://dx.doi.org/10.4028/www.scientific.net/amm.226-228.172.

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By using the finite element method, the band structures of the periodic hollow cylinder sandwich panels are investigated, and the influences of the material and geometrical parameters on the band gap are discussed in detail. The results show that The Young's modulus of panel and the coated layer have the greatest influences on the band gap of binary periodic hollow steel cylinder sandwich panels. The smaller the Young's modulus, the lower the frequency band gap. The material and geometrical parameters of the core have important influences on the lower edges of the band gap. Thicker and higher hollow steel cylinder with large density is favorable to gain a wide low-frequency band gap. The work presented will provide a theoretical guidance in the vibration isolation research.

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Kajikawa, K., M. Iwakuma, K. Funaki, M. Wada, and A. Takenaka. "Influences of geometrical configuration on AC loss measurement with pickup-coil method." IEEE Transactions on Appiled Superconductivity 9, no. 2 (June 1999): 746–49. http://dx.doi.org/10.1109/77.783402.

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SAITO, S., Y. KAKINUMA, T. AOYAMA, K. TANAKA, and H. ANZAI. "THE INFLUENCES OF THE MATERIAL AND GEOMETRICAL PROPERTIES OF SLIDING PLATE ON ERG EFFECT OF GEL-STRUCTURED ERF." International Journal of Modern Physics B 21, no. 28n29 (November 10, 2007): 4751–57. http://dx.doi.org/10.1142/s0217979207045621.

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Electro-rheological Fluid (ERF) is the functional fluid that can change its viscoelastic property by applying electric field. However, ERF shows the sedimentation of the ER particles in long time use, and it caused the unstable ER effect. The Gel-structured ERF (ERG) has been developed to solve this problem. When a metallic flat plate is placed on the ERG sheet, ERG shows the high shear force due to the occurrence of the contact between the gel and the plate in response to the applying electric field (ERG effect). ERG effect can be obtained not only for metallic materials but also non-metallic materials by applying the one-sided electrode, and the ER effect is supposed to be considerably influenced by the material and geometrical properties of flat plate on the ERG sheet. In this study, the influences of the material and geometrical properties of sliding plate are experimentally analyzed from the viewpoint of the relative permittivity, surface roughness and flatness, and the design instruction for the selection of materials and their geometrical issues are proposed.

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Kovacevic, R., Z. N. Cao, and Y. M. Zhang. "Role of Welding Parameters in Determining the Geometrical Appearance of Weld Pool." Journal of Engineering Materials and Technology 118, no. 4 (October 1, 1996): 589–96. http://dx.doi.org/10.1115/1.2805961.

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A three-dimensional numerical model is developed to describe the fluid flow and heat transfer in weld pools. Both full penetration and free deformation of the top and bottom weld pool surfaces are considered. Temperature distribution and fluid flow field are obtained. In order to analyze the influence of welding parameters on the geometrical appearance of weld pools, a normalized model is developed to characterize the geometrical appearance of weld pools. It is found that welding current can significantly affect the geometrical shape. When welding current increases, the curvature of the pool boundary at the trailing end increases. The effect of the welding speed on the geometrical appearance is slight, although its influence on the pool size is great. In the interest range of arc length (from 1 mm to 4 mm), the arc length can affect both the size and the shape of the weld pool. However, compared with the welding current and speed, its influences are much weaker. GTA welding experiments are performed to verify the validity of the numerical models. The appearance of weld pools was obtained by using machine vision and a high-shutter speed camera. It is found that the calculated results have a good agreement with the experimental ones.

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Gutsev, G. L., K. G. Belay, L. G. Gutsev, B. R. Ramachandran, and P. Jena. "Effect of hydrogenation on the structure and magnetic properties of an iron oxide cluster." Physical Chemistry Chemical Physics 20, no. 6 (2018): 4546–53. http://dx.doi.org/10.1039/c7cp08224j.

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Bogaert, J., D. Salvador-Van Eysenrod, P. Van Hecke, and I. Impens. "Geometrical consideration for evaluation of reserve design." Web Ecology 2, no. 1 (October 24, 2001): 65–70. http://dx.doi.org/10.5194/we-2-65-2001.

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Abstract. The edge effect, generated by the interaction of patch and matrix, is preferably described by the interior-to-edge ratio of the patch. This ratio quantifies the extent of microclimatic changes at the boundary, and influences nature reserve design. As shown for elliptical and rectangular shapes, large and isodiametric patch designs are characterized by high interior-to-edge ratios. Different patch geometries can however lead to similar values of the ratio. A reference value, based upon the patch size, is therefore proposed to normalize the ratio to its maximum value, as observed for a perfectly isodiametric patch. The effect of patch geometry on the normalized ratio is discussed, as well as patch ranking based upon both the simple ratio and the normalized interior-to-edge ratio. An example is included using forest patches in the Belgian Campine region to illustrate the usefulness of the proposed index.

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Sen, Pabitra N. "Influence of microgeometry on membrane potential of shaly sands." GEOPHYSICS 54, no. 12 (December 1989): 1543–53. http://dx.doi.org/10.1190/1.1442622.

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The microgeometry of the pore space influences the membrane potential [Formula: see text] and the dc electrical conductivity σ of a shaly sand in a similar manner, independent of the details of the geometry. [Formula: see text] and σ are related via the conductivities of cations and anions [Formula: see text] and [Formula: see text], and [Formula: see text]. This explicit relationship is used to investigate the role of the geometrical factors that influence both [Formula: see text] and σ in a related manner. The dependence of σ on water conductivity [Formula: see text] can be well approximated with four geometrical parameters, which can be obtained from the slopes and the intercepts of curves of σ versus [Formula: see text] at high and low salinities. I show how these geometrical factors appear in the expression for [Formula: see text] as well. The geometrical parameters, one of them being the formation factor, vary from rock to rock; and any trend in the parameters depends on the local geology. For the data on a group of 140 different cores, the geometrical factors could be well approximated by functions of porosity, cementation exponent, and charge density, to give a simple conductivity formula analogous to the empirical formulas that are most widely used in formation evaluation. These empirical factors are used to obtain an approximate formula for [Formula: see text].

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Yarici, Ismail, and Yavuz Öztürk. "Analysis of an inverted square SRR via design of experiment (DoE) approach." Journal of Electrical Engineering 72, no. 4 (August 1, 2021): 273–77. http://dx.doi.org/10.2478/jee-2021-0038.

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Abstract A design of experiment (DoE) study is presented based on an investigation of the influences of the chosen geometric parameters of an Inverted Square Split Ring Resonator on its resonance frequency. A statistical software was used to determine DoE steps and the values of chosen geometrical parameters for the experiments. The determined experiments were carried out by making simulations with electromagnetic design software. The resonator simulation outputs were analyzed by using normality tests and tools of the statistical software. By using these analyses, mainly a 2-level full factorial DoE approach, the effects of the geometrical parameters (input factors), and their interactions on the resonance frequency (response factor) were presented. In the light of our findings, this study proposes a promising path for microwave studies with several advantages such as being able to understand the dynamics of an optimized RF resonator device system, designing these kinds of devices with a few experiments, and increasing the time efficiency via reducing the number of attempts.

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Титоренко, Александр, and Aleksandr Titorenko. "Loadings and Influences of the Debris Flow on Flexible Anti-mudflow Constructions." Construction and Architecture 1, no. 1 (May 1, 2013): 38–42. http://dx.doi.org/10.12737/339.

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Shock impact of the head of mudflow on flexible anti-mudflow constructions, diagrams of loadings are shown. Estimated dependences are offered for determination of geometrical parameters flexible anti-mudflow constructions and tension and tension in a ring grid and anchors.

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Chen, Yuhang, and Wenhao Huang. "Influences of Geometrical Factors on Quantitative Surface Roughness Evaluations by Atomic Force Microscopy." Journal of Nanoscience and Nanotechnology 9, no. 2 (February 1, 2009): 893–96. http://dx.doi.org/10.1166/jnn.2009.c048.

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Dunham, J. B., and B. E. Rieman. "METAPOPULATION STRUCTURE OF BULL TROUT: INFLUENCES OF PHYSICAL, BIOTIC, AND GEOMETRICAL LANDSCAPE CHARACTERISTICS." Ecological Applications 9, no. 2 (May 1999): 642–55. http://dx.doi.org/10.1890/1051-0761(1999)009[0642:msobti]2.0.co;2.

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Lu, Dao-Ming. "Influences of Detuning on Geometrical Quantum Discord Dynamics in Double Jaynes-Cummings System." International Journal of Theoretical Physics 58, no. 5 (February 20, 2019): 1395–403. http://dx.doi.org/10.1007/s10773-019-04029-3.

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Medeiros, Luiz E., and David R. Fitzjarrald. "Stable Boundary Layer in Complex Terrain. Part II: Geometrical and Sheltering Effects on Mixing." Journal of Applied Meteorology and Climatology 54, no. 1 (January 2015): 170–88. http://dx.doi.org/10.1175/jamc-d-13-0346.1.

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AbstractThe authors examine how terrain texture and topography influence nocturnal mixing rates. Local topographic curvature and site sheltering exhibit systematic influences on nocturnal heat and momentum fluxes and the near-surface potential temperature distribution. This influence is particularly evident in hilly terrain with patchy forested areas, typical of eastern North America and many other regions. Exposure to local obstacles, quantified using Fujita’s “transmission factor,” has its maximum influence on mixing during strong winds (>5 m s−1), whereas the effects of local terrain curvature dominate under weaker winds. Such complementary dominance conditions currently limit direct comparison of the two effects. Even with a limited network of 10 stations, it is clear that preferred regions for mixing can be identified in advance given knowledge of land cover and topography. When designing a network of surface stations to be deployed in heterogeneous terrain, one should consider site curvature, slope, and exposure in addition to spatial coverage.

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van Kelle, M. A. J., P. J. A. Oomen, W. J. T. Janssen-van den Broek, R. G. P. Lopata, S. Loerakker, and C. V. C. Bouten. "Initial scaffold thickness affects the emergence of a geometrical and mechanical equilibrium in engineered cardiovascular tissues." Journal of The Royal Society Interface 15, no. 148 (November 2018): 20180359. http://dx.doi.org/10.1098/rsif.2018.0359.

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In situ cardiovascular tissue-engineering can potentially address the shortcomings of the current replacement therapies, in particular, their inability to grow and remodel. In native tissues, it is widely accepted that physiological growth and remodelling occur to maintain a homeostatic mechanical state to conserve its function, regardless of changes in the mechanical environment. A similar homeostatic state should be reached for tissue-engineered (TE) prostheses to ensure proper functioning. For in situ tissue-engineering approaches obtaining such a state greatly relies on the initial scaffold design parameters. In this study, it is investigated if the simple scaffold design parameter initial thickness, influences the emergence of a mechanical and geometrical equilibrium state in in vitro TE constructs, which resemble thin cardiovascular tissues such as heart valves and arteries. Towards this end, two sample groups with different initial thicknesses of myofibroblast-seeded polycaprolactone-bisurea constructs were cultured for three weeks under dynamic loading conditions, while tracking geometrical and mechanical changes temporally using non-destructive ultrasound imaging. A mechanical equilibrium was reached in both groups, although at different magnitudes of the investigated mechanical quantities. Interestingly, a geometrically stable state was only established in the thicker constructs, while the thinner constructs’ length continuously increased. This demonstrates that reaching geometrical and mechanical stability in TE constructs is highly dependent on functional scaffold design.

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Xie, Junfeng, Fan Mo, Chao Yang, Pin Li, and Shiqiang Tian. "A NOVEL SUB-PIXEL MATCHING ALGORITHM BASED ON PHASE CORRELATION USING PEAK CALCULATION." ISPRS - International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences XLI-B1 (June 3, 2016): 253–57. http://dx.doi.org/10.5194/isprsarchives-xli-b1-253-2016.

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The matching accuracy of homonymy points of stereo images is a key point in the development of photogrammetry, which influences the geometrical accuracy of the image products. This paper presents a novel sub-pixel matching method phase correlation using peak calculation to improve the matching accuracy. The peak theoretic centre that means to sub-pixel deviation can be acquired by Peak Calculation (PC) according to inherent geometrical relationship, which is generated by inverse normalized cross-power spectrum, and the mismatching points are rejected by two strategies: window constraint, which is designed by matching window and geometric constraint, and correlation coefficient, which is effective for satellite images used for mismatching points removing. After above, a lot of high-precise homonymy points can be left. Lastly, three experiments are taken to verify the accuracy and efficiency of the presented method. Excellent results show that the presented method is better than traditional phase correlation matching methods based on surface fitting in these aspects of accuracy and efficiency, and the accuracy of the proposed phase correlation matching algorithm can reach 0.1 pixel with a higher calculation efficiency.

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Xie, Junfeng, Fan Mo, Chao Yang, Pin Li, and Shiqiang Tian. "A NOVEL SUB-PIXEL MATCHING ALGORITHM BASED ON PHASE CORRELATION USING PEAK CALCULATION." ISPRS - International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences XLI-B1 (June 3, 2016): 253–57. http://dx.doi.org/10.5194/isprs-archives-xli-b1-253-2016.

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The matching accuracy of homonymy points of stereo images is a key point in the development of photogrammetry, which influences the geometrical accuracy of the image products. This paper presents a novel sub-pixel matching method phase correlation using peak calculation to improve the matching accuracy. The peak theoretic centre that means to sub-pixel deviation can be acquired by Peak Calculation (PC) according to inherent geometrical relationship, which is generated by inverse normalized cross-power spectrum, and the mismatching points are rejected by two strategies: window constraint, which is designed by matching window and geometric constraint, and correlation coefficient, which is effective for satellite images used for mismatching points removing. After above, a lot of high-precise homonymy points can be left. Lastly, three experiments are taken to verify the accuracy and efficiency of the presented method. Excellent results show that the presented method is better than traditional phase correlation matching methods based on surface fitting in these aspects of accuracy and efficiency, and the accuracy of the proposed phase correlation matching algorithm can reach 0.1 pixel with a higher calculation efficiency.

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GHEDHAB, Mohamed Elamine, Ikram El ABBASSI, Rafik ABSI, and Yannick MÉLINGE. "Numerical study of the effect of DSF walls geometrical shape on heat transfer." E3S Web of Conferences 170 (2020): 01005. http://dx.doi.org/10.1051/e3sconf/202017001005.

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The building envelope is an important element that influences energy performance, both in terms of gains and losses. Indeed, much research has focused on improving and optimizing this element. The façade represents the main component of the envelope; it plays a crucial role lying in the protection of the internal environment of the building from external climate variations, by providing thermal comfort to its occupants. In order to gain in energy efficiency, a numerical investigation (CFD) on the influence of the geometric shape of façades on heat exchange in the building is carried out in this work. More particularly, the study will be established on double skin façades (DSF) representing the most commonly used facade typology on high-rise buildings. The simulations will be carried out taking into account the climate in Paris region. The first part will be dedicated to the definition of the basic model, which will be considered as a reference case with plan surfaces on the outside and inside of the building. In the second part, the influence of the shape of the external façade on heat exchange will be discussed.

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Thu, Pham Van, and Nguyen Dinh Duc. "Non-linear dynamic response and vibration of an imperfect three-phase laminated nanocomposite cylindrical panel resting on elastic foundations in thermal environments." Science and Engineering of Composite Materials 24, no. 6 (November 27, 2017): 951–62. http://dx.doi.org/10.1515/secm-2015-0467.

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AbstractThis paper presents an analytical approach to investigate the non-linear dynamic response and vibration of an imperfect three-phase laminated nanocomposite cylindrical panel resting on elastic foundations in thermal environments. Based on the classical laminated shell theory and stress function, taking into account geometrical non-linearity, initial geometrical imperfection, Pasternak-type elastic foundation, and temperature, the governing equations of the three-phase laminated nanocomposite cylindrical panel are derived. The numerical results for the dynamic response and vibration of the polymer nanocomposite cylindrical panel are obtained by using the Runge-Kutta method. The influences of fibres and nanoparticles, different fibre angles, material and geometrical properties, imperfection, elastic foundations, and temperature on the non-linear dynamic response of the polymer nanocomposite cylindrical panel are discussed in detail.

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Yi, Zhuang Peng, Lian Hua Wang, and Guang Ya Tu. "The In-Plane Buckling of Elastic Support Circular Arches Considering the Geometrical Imperfections." Advanced Materials Research 639-640 (January 2013): 786–89. http://dx.doi.org/10.4028/www.scientific.net/amr.639-640.786.

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The equilibrium equations of elastic support circular arches considering geometrical imperfections are deduced from variation principle. And the relations between external load, radial displacement and axial forces are determined; also the equilibrium conditions of snap-through buckling and bifurcation buckling in circular arch are ascertained respectively. Further, influences of geometrical imperfections and elastic supports on in-plane stability are analysis with analytical and finite element (FE) method. And the compared results display that the two methods coincide with each other very well for smaller opening angle in circular arches. The geometrical imperfections have only certain effects on the buckling path, while the elastic support rigidity play a significant role in both the path and critical load of snap-through buckling.

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Wang, Wen Qi, Dong Xiang Shao, Jian Feng Jiang, and Guang Lin Wang. "Research on Optical Microscope Measuring Method of External Thread Parameters Based on Charge-Couple Device." Applied Mechanics and Materials 163 (April 2012): 39–43. http://dx.doi.org/10.4028/www.scientific.net/amm.163.39.

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As an important component of the fasteners members, threads quality, depending on whether its geometric parameters meet requirements or not, will affect the reliability of the whole machine system. Therefore, geometrical parameters measurement of the thread is especially important. Aiming at the characteristics of the thread teeth type, this paper adopt a machine vision measurement method based on the universal tool microscope and CCD .This paper also analyzes the causes and influences of the teeth shading and proposes a corresponding improvement method, specific to the shading problem in the process of backlighting projection. After experimenting, this method can effectively improve the accuracy and efficiency of the male parameters measurement.

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Abdel-Fattah, Mohamed I., and Ahmed Y. Tawfik. "3D Geometric Modeling of the Abu Madi Reservoirs and Its Implication on the Gas Development in Baltim Area (Offshore Nile Delta, Egypt)." International Journal of Geophysics 2015 (2015): 1–11. http://dx.doi.org/10.1155/2015/369143.

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3D geometric modeling has received renewed attention recently, in the context of visual scene understanding. The reservoir geometry of the Baltim fields is described by significant elements, such as thickness, depth maps, and fault planes, resulting from an interpretation based on seismic and well data. Uncertainties affect these elements throughout the entire interpretation process. They have some bearing on the geometric shape and subsequently on the gross reservoir volume (GRV) of the fields. This uncertainty on GRV also impacts volumes of hydrocarbons in place, reserves, and production profiles. Thus, the assessment of geometrical uncertainties is an essential first step in a field study for evaluation, development, and optimization purposes. Seismic data are best integrated with well and reservoir information. A 3D geometric model of the Late Messinian Abu Madi reservoirs in the time and depth domain is used to investigate the influence of the reservoir geometry on the gas entrapment. Important conceptual conclusions about the reservoir system behavior are obtained using this model. The results show that the reservoir shape influences the seismic response of the incised Abu Madi Paleovalley, making it necessary to account for 3D effects in order to obtain accurate results.

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Liu, Jiaqiong, Bo Yan, Zheyue Mou, Yingbo Gao, Getu Niu, and Xiaolin Li. "Numerical study of aeolian vibration characteristics and fatigue life estimation of transmission conductors." PLOS ONE 17, no. 1 (January 26, 2022): e0263163. http://dx.doi.org/10.1371/journal.pone.0263163.

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The 2D computational fluid dynamics (CFD) model of transmission conductor is set up to simulate the aerodynamic forces varying with time on the conductor. Taking into account the geometrical nonlinearity of conductor lines, the finite element (FE) models of single span and two-span transmission lines discretized with beam elements are established. By means of the FE models, the aeolian vibrations of the conductor lines excited by the aerodynamic forces under different wind velocities are numerically simulated. The nonlinear resonant characteristics, the amplitude-frequency relations of the conductor lines during aeolian vibration are investigated, and the influences of the span length as well as the initial tension in conductors on the aeolian vibration characteristics are analyzed. Furthermore, a 3D FE model of a conductor segment and the suspension clamp is created to study the stress distributions of the 3D model corresponding to different lines during aeolian vibrations. Finally, based on the stress analysis of the 3D model, the fatigue lives of the transmission conductors during aeolian vibration under different wind velocities are estimated. The jump phenomenon induced by the nonlinear vibration is reflected by the numerical simulation considering the geometric nonlinearity, and it is found that the energy balance principle (EBP) overestimates the vibration amplitudes because it cannot take the influences of the geometrical nonlinearity and span length into account. The obtained results may provide some instructions for the prevention design of aeolian vibration.

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Trigona, Carlo, Giovanna Di Pasquale, Salvatore Graziani, Antonino Licciulli, Rossella Nisi, and Antonino Pollicino. "Geometrical and thermal influences on a bacterial cellulose based sensing element for acceleration measurements." ACTA IMEKO 9, no. 4 (December 17, 2020): 151. http://dx.doi.org/10.21014/acta_imeko.v9i4.742.

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The need for a sustainable economy necessitates new environmentally friendly production technologies as well as devices that can be easily recycled, disposed of, and, finally, degraded, without any release of pollutants to the environment. In this context, bacterial cellulose (BC) has recently been investigated as an intriguing solution for the creation of green motion sensors. BC has excellent mechanical properties, and it is fully biodegradable and greener than the more common plant-derived cellulose. In this paper, we investigate the influence of geometry and environmental temperature on BC based sensing elements. More specifically, the influence of these quantities on a previously investigated BC-based accelerometer are reported. An experimental campaign and the characterization of the proposed green device for several geometries (from 7 to 22 mm of length) and various temperatures (from 5 °C to 55 °C) is addressed, obtaining very intriguing results.

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Li, Zhen, and Bing Yan. "Ball-End Cutter Machining Process Analysis in Five-Axis Milling." Applied Mechanics and Materials 34-35 (October 2010): 903–8. http://dx.doi.org/10.4028/www.scientific.net/amm.34-35.903.

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In this paper, the three dimensional geometrical analysis is depicted with the interacting relations among cutting edge, undeformed chip and shear zone along cutting direction, and a general geometrical model of five-axis machining curve surface in ball-end milling is presented. A general force model is derived, and the three dimensional cutting forces are predicted. The influences of different angle of the centerline of the cutter to the cutting forces are considered. The three dimensional cutting forces are applied to construct and analysis the structural vibratory model of the system.

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Hutli, Ezddin, Salem Abouali, Ben Hucine, Mohamed Mansour, Milos Nedeljkovic, and Vojislav Ilic. "Influences of hydrodynamic conditions, nozzle geometry on appearance of high submerged cavitating jets." Thermal Science 17, no. 4 (2013): 1139–49. http://dx.doi.org/10.2298/tsci120925045h.

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Based on visualization results of highly-submerged cavitating water jet obtained with digital camera, the influences of related parameters such as: injection pressure, nozzle diameter and geometry, nozzle mounting (for convergent / divergent flow), cavitation number and exit jet velocity, were investigated. In addition, the influence of visualization system position was also studied. All the parameters have been found to be of strong influence on the jet appearance and performance. Both hydro-dynamical and geometrical parameters are playing the main role in behavior and intensity of cavitation phenomenon produced by cavitating jet generator. Based on our considerable previous experience in working with cavitating jet generator, the working conditions were chosen in order to obtain measurable phenomenon.

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Gutsche, Philipp, Xavier Garcia-Santiago, Philipp-Immanuel Schneider, Kevin M. McPeak, Manuel Nieto-Vesperinas, and Sven Burger. "Role of Geometric Shape in Chiral Optics." Symmetry 12, no. 1 (January 13, 2020): 158. http://dx.doi.org/10.3390/sym12010158.

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The distinction of chiral and mirror symmetric objects is straightforward from a geometrical point of view. Since the biological as well as the optical activity of molecules strongly depend on their handedness, chirality has recently attracted high interest in the field of nano-optics. Various aspects of associated phenomena including the influences of internal and external degrees of freedom on the optical response have been discussed. Here, we propose a constructive method to evaluate the possibility of observing any chiral response from an optical scatterer. Based on solely the T-matrix of one enantiomer, planes of minimal chiral response are located and compared to geometric mirror planes. This provides insights into the relation of geometric and optical properties and enables identifying the potential of chiral scatterers for nano-optical experiments.

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Sirousazar, Mohammad. "Approximate Mathematical Modeling of Osmotic Dehydration of Cone-Shaped Fruits and Vegetables in Hypertonic Solutions." Turkish Journal of Agriculture - Food Science and Technology 5, no. 6 (July 12, 2017): 581. http://dx.doi.org/10.24925/turjaf.v5i6.581-585.821.

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Water loss kinetics in osmotic dehydration of cone-shaped fruits and vegetables was modeled on the basis of diffusion mechanism, using the Fick’s second law. The model was developed by taking into account the influences of the fruit geometrical characteristics, initial water content of fruit, water diffusion coefficient in fruit, and the water concentration in hypertonic solution. Based on the obtained model, it was shown that the water diffusion coefficient and the initial water concentration of fruit have direct effects on the dehydration rate and also inverse influence on the dehydration duration. The geometrical parameters of fruit and water concentration in hypertonic solution showed direct effect on the dehydration duration as well as inverse effect on the dehydration rate. The presented model seems to be useful tool to predict the dehydration kinetics of cone-shaped fruit during osmotic dehydration process and to optimize the process prior to perform the experiments.

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Asano, Yusuke, Ryoshu Furutani, and Miyu Ozaki. "Verification of Interim Check Method of CMM." International Journal of Automation Technology 5, no. 2 (March 5, 2011): 115–19. http://dx.doi.org/10.20965/ijat.2011.p0115.

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In industry, the Coordinate Measuring Machine (CMM) is a major geometrical measurement method because of its precision and general versatility. The CMM is conventionally used in a thermostatic chamber, but its use in the production line environment is increasing. Many factors - dust, thermal fluctuation, and collision, to name a few - deteriorate measurement precision and make it necessary to inspect the CMM daily. However, the daily inspection method is not established. Study of CMM is mainly about calibration in controlled environment like a thermostatic chamber. It is unfeasible to calibrate the CMM everyday because of its cost. So some researchers have studied about daily inspection of CMM. This paper describes daily CMM inspection procedures and how to evaluate these uncertainty. This method treats axis scale errors and interaxis squareness errors from geometric errors of CMM. These factors influence the measurand. QuickCheck (Trapet Precision Engineering) is used as an artifact. In the linear model using QuickCheck, influences of alignment error is evaluated parameters.

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Vatter, Peter, and Raoul Plettke. "Geometrical variations of tubes and their impact on freeform bending processes." Advanced Materials Research 769 (September 2013): 181–88. http://dx.doi.org/10.4028/www.scientific.net/amr.769.181.

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In bending processes for tubes and profiles, the produced bending geometry depends on the characteristics of the semifinished product. Tubes are subjected to scatter and deviations from the standard’s dimensions caused by their fabrication process. This results in deviations of the forming behaviour. Depending on the bending process, the effect of this phenomenon is even larger, if the deviation of process forces leads to a significant deflection of the die elements. Particularly kinematic bending processes, e. g. the 3-roll-push-bending process have shown to be highly sensitive to low machine stiffness. The effect of this factor has not been identified among the influences of other disturbance factors so far. As an additional aspect, the tube dimensions affect the material characterization which leads to inaccurate material properties in numerical simulations. This results in wrong input data for the process design and has to be corrected in lengthy adjustment procedures. In this contribution the scatter of some geometrical tubes properties and its impact on the 3-roll-push-bending process is investigated. The tube geometry is measured by a tactile measurement system and is compared to the product standards. Observed deviations are categorized according to DIN 4760. The impact of the deviations on the bending process is examined by numerical variant calculations. Besides the tube dimensions, the stiffness of the machine is varied and the influence determined. By considering the errors resulting from wrong input data in the material characterization the overall error is quantified.

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Khoa, Nguyen Dinh, and Pham Dinh Nguyen. "Analytical investigation on nonlinear dynamic behavior and free vibration analysis of laminated nanocomposite plates." Proceedings of the Institution of Mechanical Engineers, Part C: Journal of Mechanical Engineering Science 233, no. 19-20 (August 25, 2019): 6866–78. http://dx.doi.org/10.1177/0954406219870586.

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This work presents the results of the dynamic behavior and natural frequencies of laminated polymer plates that are reinforced by carbon nanotubes. The laminated nanocomposite plates have two components: carbon nanotubes reinforced in different polymer matrices. The nonlinear equations are obtained by Reddy's third-order laminated plate theory with von Kármán's geometrical nonlinearity and solved by both Runge–Kutta and Galerkin methods. Detailed studies for the influences of carbon nanotubes' different types of reinforcements and weight fractions, geometrical parameters, Winkler and Pasternak foundations on the deflection–time curves, and natural frequencies of laminated functionally graded carbon nanotube-reinforced composite plates are examined.

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Arivazhagan, R., C. Dominic Savio, K. Aakash, M. Ahamed Abuthahir, and C. Ganesh. "An Investigation on Cut Quality of Aluminum Matrix Composites Cut by Abrasive Waterjet." International Journal for Research in Applied Science and Engineering Technology 10, no. 4 (April 30, 2022): 535–43. http://dx.doi.org/10.22214/ijraset.2022.41263.

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Abstract: Metal matrix composites are difficult to machine in traditional machining methods. Abrasive water jet machining is a state-of-the art technology which enables machining of practically all engineering materials. Abrasive water jet machining is a very efficient machining process which overcomes tool wear issues and cutting temperature issues. This experimental investigates a particular study performed on hybrid metal matrix composites prepared by AA6082 and reinforced 7.5% of TiB2 and 1% graphite in aluminum alloy and processed with abrasive water jets that are formed with garnet 80 mesh size. Particularly roughness average majorly influences with water jet traverse speed. Among interaction effects stand of distance is majorly influenced with geometrical properties except diameter error. Although developing the statistical models for predicting the machining characteristics and geometrical accuracy and the study carried out in this work would help to choose the parameters carefully. Keywords: Abrasive Waterjet Cutting, Abrasives, Metal Matrix Composites, Sand Casting

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Li, Feng, Qilin Zhao, Li Chen, and Guojian Shao. "Experimental and Theoretical Research on the Compression Performance of CFRP Sheet Confined GFRP Short Pipe." Scientific World Journal 2014 (2014): 1–12. http://dx.doi.org/10.1155/2014/109692.

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The axial compressive strength of unidirectional FRP made by pultrusion is generally quite lower than its axial tensile strength. This fact decreases the advantages of FRP as main load bearing member in engineering structure. A theoretical iterative calculation approach was suggested to predict the ultimate axial compressive stress of the combined structure and analyze the influences of geometrical parameters on the ultimate axial compressive stress of the combined structure. In this paper, the experimental and theoretical research on the CFRP sheet confined GFRP short pole was extended to the CFRP sheet confined GFRP short pipe, namely, a hollow section pole. Experiment shows that the bearing capacity of the GFRP short pipe can also be heightened obviously by confining CFRP sheet. The theoretical iterative calculation approach in the previous paper is amended to predict the ultimate axial compressive stress of the CFRP sheet confined GFRP short pipe, of which the results agree with the experiment. Lastly the influences of geometrical parameters on the new combined structure are analyzed.

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Rodrigues, António Manuel, and José António Tenedório. "Sensitivity Analysis of Spatial Autocorrelation Using Distinct Geometrical Settings." International Journal of Agricultural and Environmental Information Systems 7, no. 1 (January 2016): 65–77. http://dx.doi.org/10.4018/ijaeis.2016010105.

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Inferences based on spatial analysis of areal data depend greatly on the method used to quantify the degree of proximity between spatial units - regions. These proximity measures are normally organized in the form of weights matrices, which are used to obtain statistics that take into account neighbourhood relations between agents. In any scientific field where the focus is on human behaviour, areal datasets are greatly relevant since this is the most common form of data collection (normally as count data). The method or schema used to divide a continuous spatial surface into sets of discrete units influences inferences about geographical and social phenomena, mainly because these units are neither homogeneous nor regular. This article tests the effect of different geometrical data aggregation schemas - administrative regions and hexagonal surface tessellation - on global spatial autocorrelation statistics. Two geographical variables are taken into account: scale (resolution) and form (regularity). This is achieved through the use of different aggregation levels and geometrical schemas. Five different datasets are used, all representing the distribution of resident population aggregated for two study areas, with the objective of consistently test the effect of different spatial aggregation schemas.

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Journal articles on the topic 'Geometrical influences'

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