Gotowe bibliografie tematyczne / Strongly orthotropic

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Gotowa bibliografia na temat „Strongly orthotropic”

Autor: Grafiati

Data publikacji: 4 czerwca 2021

Data aktualizacji: 13 lutego 2022

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Artykuły w czasopismach na temat "Strongly orthotropic"

Savoia, Marco, i Nerio Tullini. "Beam theory for strongly orthotropic materials". International Journal of Solids and Structures 33, nr 17 (lipiec 1996): 2459–84. http://dx.doi.org/10.1016/0020-7683(95)00163-8.

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Kellermann, D. C., T. Furukawa i D. W. Kelly. "Strongly orthotropic continuum mechanics and finite element treatment". International Journal for Numerical Methods in Engineering 76, nr 12 (17.12.2008): 1840–68. http://dx.doi.org/10.1002/nme.2379.

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Amir, S. "Orthotropic patterns of visco-Pasternak foundation in nonlocal vibration of orthotropic graphene sheet under thermo-magnetic fields based on new first-order shear deformation theory". Proceedings of the Institution of Mechanical Engineers, Part L: Journal of Materials: Design and Applications 233, nr 2 (22.09.2016): 197–208. http://dx.doi.org/10.1177/1464420716670929.

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In the present research, vibration and instability of orthotropic graphene sheet subjected to thermo-magnetic fields are investigated. Orthotropic visco-Pasternak foundation is considered to analyze the influences of orthotropy angle, damping coefficient, normal and shear modulus. New first-order shear deformation theory is utilized due to accuracy of its polynomial functions compared to other theories of plate. Motion equations are obtained by means of Hamilton’s principle and then solved analytically. Influences of various parameters such as small scale, magnetic field, orthotropic viscoelastic surrounding medium, thickness and aspect ratio of single layer graphene sheet on the vibration characteristics of nanoplate are discussed in detail. The results indicate that the stability of single layer graphene sheet is strongly dependent on applied magnetic field. Therefore, the mechanical behavior of single layer graphene sheet can be improved by applying magnetic field. The results of this investigation can be used in design and manufacturing of micro/nano mechanical systems.

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Sobota, P. M., i K. A. Seffen. "Bistable polar-orthotropic shallow shells". Royal Society Open Science 6, nr 8 (sierpień 2019): 190888. http://dx.doi.org/10.1098/rsos.190888.

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We investigate stabilizing and eschewing factors on bistability in polar-orthotropic shells in order to enhance morphing structures. The material law causes stress singularities when the circumferential stiffness is smaller than the radial stiffness ( β < 1), requiring a careful choice of the trial functions in our Ritz approach, which employs a higher-order geometrically nonlinear analytical model. Bistability is found to strongly depend on the orthotropic ratio, β , and the in-plane support conditions. An investigation of their interaction offers a new perspective on the effect of the hoop stiffness on bistability: while usually perceived as promoting, it is shown to be only stabilizing insofar as it prevents radial expansions; however, if in-plane supports are present, it becomes a redundant feature. Closed-form approximations of the bistable threshold are then provided by single-curvature-term approaches. For significantly stiffer values of the radial stiffness, a strong coupling of the orthotropic ratio and the support conditions is revealed: while roller-supported shells are monostable, fixed-pinned ones are most disposed to stable inversions; insight is given by comparing to a simplified beam model. Eventually, we show that cutting a central hole is a suitable method to deal with stress singularities: while fixed-pinned shells are barely affected by a hole, the presence of a hole strongly favours bistable inversions in roller-supported shells.

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Zarandi, Somayeh, Hsiang-Wei Lai, Yun-Che Wang i Sergey Aizikovich. "Residual Stress Analysis of an Orthotropic Composite Cylinder under Thermal Loading and Unloading". Symmetry 11, nr 3 (4.03.2019): 320. http://dx.doi.org/10.3390/sym11030320.

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Elastoplastic analysis of a composite cylinder, consisting of an isotropic elastic inclusion surrounded by orthotropic matrix, is conducted via numerical parametric studies for examining its residual stress under thermal cycles. The matrix is assumed to be elastically and plastically orthotropic, and all of its material properties are temperature-dependent (TD). The Hill’s anisotropic plasticity material model is adopted. The interface between the inclusion and matrix is perfectly bonded, and the outer boundary of the cylinder is fully constrained. A quasi-static, uniform temperature field is applied to the cylinder, which is analyzed under the plane-strain assumption. The mechanical responses of the composite cylinder are strongly affected by the material symmetry and temperature-dependent material properties. When the temperature-independent material properties are assumed, larger internal stresses at the loading phase are predicted. Furthermore, considering only yield stress being temperature dependent may be insufficient since other TD material parameters may also affect the stress distributions. In addition, plastic orthotropy inducing preferential yielding along certain directions leads to complex residual stress distributions when material properties are temperature-dependent.

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Fink, Marcel, Olaf Andersen, Torsten Seidel i André Schlott. "Strongly Orthotropic Open Cell Porous Metal Structures for Heat Transfer Applications". Metals 8, nr 7 (19.07.2018): 554. http://dx.doi.org/10.3390/met8070554.

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For modern thermal applications, open cell porous metals provide interesting opportunities to increase performance. Several types of cellular metals show an anisotropic morphology. Thus, using different orientations of the structure can boost or destroy the performance in thermal applications. Examples of such cellular anisotropic structures are lotus-type structures, expanded sheet metal, and metal fiber structures. Lotus-type structures are made by casting and show unidirectional pores, whereas expanded sheet metal structures and metal fiber structures are made from loose semi-finished products that are joined by sintering and form a fully open porous structure. Depending on the type of structure and the manufacturing process, the value of the direction-dependent heat conductivity may differ by a factor of 2 to 25. The influence of the measurement direction is less pronounced for the pressure drop; here, the difference varies between a factor of 1.5 to 2.8, depending on the type of material and the flow velocity. Literature data as well as own measurement methods and results of these properties are presented and the reasons for this strongly anisotropic behavior are discussed. Examples of advantageous applications, for example a latent heat storage device and a heat exchanger, where the preferential orientations are exploited in order to gain the full capacity of the structure’s performance, are introduced.

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A., Jayantha Pasdunkorale, i Ian W. Turner. "Generalised finite volume strategies for simulating transport in strongly orthotropic porous media". ANZIAM Journal 44 (1.04.2003): 443. http://dx.doi.org/10.21914/anziamj.v44i0.690.

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Kunte, M. V., i Venkata R. Sonti. "Asymptotic wavenumber expansions of a strongly orthotropic fluid-filled circular cylindrical shell". Wave Motion 50, nr 3 (kwiecień 2013): 402–14. http://dx.doi.org/10.1016/j.wavemoti.2012.10.003.

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Filiou, C., i C. Soutis. "Approximate Biaxial Stress Solution for Orthotropic Open-Hole Composite Laminates". Advanced Composites Letters 5, nr 4 (lipiec 1996): 096369359600500. http://dx.doi.org/10.1177/096369359600500402.

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A simple approximate solution has been derived for the stress distribution near a circular hole applicable to any orthotropic composite laminate subjected to biaxial loading. The degree of accuracy of this solution was found to be overall acceptable, but strongly dependent upon the laminate lay-up and biaxiality ratio.

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Cansiz, Baris, Hüsnü Dal i Michael Kaliske. "Computational modeling of cardiac tissue with strongly coupled electromechanics and orthotropic viscoelastic effects". PAMM 14, nr 1 (grudzień 2014): 119–20. http://dx.doi.org/10.1002/pamm.201410047.

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Rozprawy doktorskie na temat "Strongly orthotropic"

Kellermann, David Conrad Mechanical &amp Manufacturing Engineering Faculty of Engineering UNSW. "Strongly orthotropic continuum mechanics". Publisher:University of New South Wales. Mechanical & Manufacturing Engineering, 2008. http://handle.unsw.edu.au/1959.4/41454.

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The principal contribution of this dissertation is a theory of Strongly Orthotropic Continuum Mechanics that is derived entirely from an assertion of geometric strain indeterminacy. Implementable into the finite element method, it can resolve widespread kinematic misrepresentations and offer unique and purportedly exact strain-induced energies by removing the assumptions of strain tensor symmetry. This continuum theory births the proposal of a new class of physical tensors described as the Intrinsic Field Tensors capable of generalising the response of most classical mechanical metrics, a number of specialised formulations and the solutions shown to be kinematically intermediate. A series of numerical examples demonstrate Euclidean objectivity, material frame-indifference, patch test satisfaction, and agreement between the subsequent Material Principal Co-rotation and P??I??C decomposition methods that produce the intermediary stress/strain fields. The encompassing theory has wide applicability owing to its fundamental divergence from conventional mechanics, it offers non-trivial outcomes when applied to even very simple problems and its use of not the Eulerian, Lagrangian but the Intrinsic Frame generates previously unreported results in strongly orthotropic continua.

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Części książek na temat "Strongly orthotropic"

Liu, C., X. Yang, H. Zhao i Z. Zheng. "Homotopy perturbation solution for strong geometrical nonlinear vibration of flat prestressed orthotropic membrane structure". W Shell Structures: Theory and Application, 313–16. CRC Press, 2013. http://dx.doi.org/10.1201/b15684-77.

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Streszczenia konferencji na temat "Strongly orthotropic"

Bahadur, Raj, i Avram Bar-Cohen. "Orthotropic Thermal Conductivity Effect on Cylindrical Pin Fin Heat Transfer". W ASME 2005 Pacific Rim Technical Conference and Exhibition on Integration and Packaging of MEMS, NEMS, and Electronic Systems collocated with the ASME 2005 Heat Transfer Summer Conference. ASMEDC, 2005. http://dx.doi.org/10.1115/ipack2005-73181.

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There is growing interest in the use of polymer composites with enhanced thermal conductivity for high performance fin arrays and heat sinks. However, the thermal conductivity of these materials is relatively low compared to conventional fin metals, and strongly orthotropic. Therefore, the design and optimization of such polymer pin fins requires extension of the one dimensional classical fin analysis to include two-dimensional orthotropic heat conduction effects. An analytical equation for heat transfer from a cylindrical pin fin with orthotropic thermal conductivity is derived and validated using detailed finite-element results. The thermal performance of such fins was found to be dominated by the axial thermal conductivity, but to depart from the classical fin solution with increasing values of a radius- and radial conductivity-based Biot number. Using these relations, it is determined that fin orthotropy does not materially affect the behavior of typical air-cooled fins. Alternatively, for heat transfer coefficients achievable with water cooling and conductivity ratios below 0.1, the fin heat transfer rate can fall more than 25% below the “classical” heat transfer rates. Detailed orthotropic fin temperature distributions are used to explain this discrepancy. Simplified orthotropic pin fin heat transfer equations are derived and validated over a wide range of orthotropic conditions.

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Khalilollahi, Amir, i Russell L. Warley. "Thermal Stress Reduction and Optimization for Orthotropic Composite Boards". W ASME 2005 Summer Heat Transfer Conference collocated with the ASME 2005 Pacific Rim Technical Conference and Exhibition on Integration and Packaging of MEMS, NEMS, and Electronic Systems. ASMEDC, 2005. http://dx.doi.org/10.1115/ht2005-72570.

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Composite printed electronic boards are susceptible of structural failure or irreversible damage under thermally raised stresses. A thermal/structural finite element model is integrated in this study to enable the predictions of the temperature and stress distribution of vertically clamped parallel circuit boards that include series of symmetrically mounted heated electronic modules (chips). The board is modeled as a thin plate containing four heated flush rectangular areas that represent the electronic modules. The finite element model should be to able to accept the convection heat transfer on the board surface, heat generation in the modules, and directional conduction inside the board. A detailed 3-D CFD model is incorporated to predict the conjugate heat transfer coefficients that strongly affect the temperature distribution in the board and modules. Structural analyses are performed by a FE model that uses the heat transfer coefficients mentioned above, and structural elements capable of handling orthotropic material properties. The stress fields are obtained and compared for the models possessing different fiber orientations and fiber volume fractions. Appreciable differences in stress and thermal gradient fields were observed. The values of fiber volume fraction and fiber orientation at which to conduct analyses was guided by experimental design (DOE) ideas leading to a metamodel of the stress intensity and temperature gradient in the board which was used to represent the complied results of this study.

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Coudrillier, Baptiste, Craig Boote i Thao D. Nguyen. "Effects of the Scleral Collagen Structure on the Biomechanical Response of the Optic Nerve Head". W ASME 2012 Summer Bioengineering Conference. American Society of Mechanical Engineers, 2012. http://dx.doi.org/10.1115/sbc2012-80540.

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The sclera is a fiber-reinforced material composed of dense superimposed lamellae of type I collagen fibrils embedded in a matrix of elastin and proteoglycan. Recent Wide-Angle X-ray Scattering (WAXS) experiments (Meek, 2009) showed that the collagen lamellae are strongly aligned circumferentially in the region closest to the optic nerve head (ONH). The collagen structure was more disperse and heterogeneous away from the peripapillary region. The collagen structure of the sclera directly influences its material stiffness properties and therefore the level of strain transmitted to the tissues of the ONH, which is the primary site of damage in glaucoma. The effects of the fiber structure on the ONH biomechanics have been studied on the monkey eye (Girard, 2009), but not on the human eye. Recent work evaluating the influence of the human sclera on ONH biomechanics approximated the scleral behavior as linear elastic (Sigal, 2009) or hyperelastic orthotropic (Eilaghi, 2009).

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Khalilollahi, Amir, Russell L. Warley i Oladipo Onipede. "Thermal Reliability Design and Optimization for Multilayer Composite Electronic Boards". W ASME 2005 International Mechanical Engineering Congress and Exposition. ASMEDC, 2005. http://dx.doi.org/10.1115/imece2005-82560.

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Boards made of composites are susceptible of structural failure or irreversible damage under thermally raised stresses. A thermal/structural finite element model is integrated in this study to enable the predictions of the temperature and stress distribution of vertically clamped parallel circuit boards that include series of symmetrically mounted heated electronic modules (chips). The board is modeled as a thin plate containing four heated flush rectangular areas that represent the electronic modules. The finite element model should be to able to accept the convection heat transfer on the board surface, heat generation in the modules, and directional conduction inside the board. A detailed 3-D CFD model is incorporated to predict the conjugate heat transfer coefficients that strongly affect the temperature distribution in the board and modules. Structural analyses are performed by a FE model that uses the heat transfer coefficients mentioned above, and structural elements capable of handling orthotropic material properties. The stress fields are obtained and studied for the models possessing two and there laminates with different fiber orientations, and inter-fiber angles. Appreciable differences in values of max stress intensity were observed as the fiber orientation and inter-fiber angle changed. The angular parameters in this study were guided by experimental design (DOE) concepts leading to a metamodel of the stress intensity in the board. The optimum design variables found by the equations of the metamodel.

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Dubois, P. K., A. Gauvin-Verville, B. Picard, J. S. Plante i M. Picard. "Thermal Barrier Coating Applied to the Structural Shroud of an Inside-Out Ceramic Turbine". W ASME Turbo Expo 2021: Turbomachinery Technical Conference and Exposition. American Society of Mechanical Engineers, 2021. http://dx.doi.org/10.1115/gt2021-58972.

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Abstract Recuperated, high-temperature microturbines (< 1 MW) could be a key enabler for hybrid powertrains of tomorrow’s small aircraft. To achieve competitive thermal efficiencies, turbine inlet temperature (TIT) must increase to 1550 K, well beyond conventional metallic microturbine limits. This calls for high-temperature refractory ceramics, which call for a new ceramic-specific, microturbine design like the Inside-Out Ceramic Turbine (ICT). This study focuses on the applicability of a refractory thermal barrier coating (TBC) to the internal surface of the ICT cooling ring. By cutting the heat transfer from the main flow to the structural rim-rotor, the use of a refractory TBC coating in an ICT enables higher TIT and lower cooling air mass flow. A preliminary experimental assessment is done at room temperature on 1 mm-thick coatings of 8% yttria-stabilized zirconia (8YSZ), air plasma sprayed (APS) TBC, applied to Inconel 718 and Ti64 test coupons. Results show that the strongly orthotropic behaviour of the tested TBC fits perfectly with the deformation mechanics of the ICT configuration under load. First, large in-plane strain tolerance allows the large tangential deformation imposed by the structural shroud under centrifugal loading. Second, high out-of-plane stiffness and compressive resistance combine to support extreme compressive loads with no apparent damage to the TBC even at more than 3 times blade indentation average loading. An experimental demonstration on a small-scale prototype shows a reduction of 40% in cooling flow in a, 8-minute ICT test, with no damage to the TBC, proving the effectiveness and potential of the proposed TBC design.

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Shabany, Younes. "Effects of Boundary Conditions and Source Dimensions on the Effective Thermal Conductivity of a Printed Circuit Board". W ASME 2003 International Electronic Packaging Technical Conference and Exhibition. ASMEDC, 2003. http://dx.doi.org/10.1115/ipack2003-35201.

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The heat conduction equation and its boundary conditions were used to show that the planar and normal thermal conductivities of an orthotropic model of a printed circuit board were functions of source to board size ratio, top and bottom side boundary conditions, and thickness and thermal conductivity of each layer. Numerical solutions of the heat conduction equation were used to quantify the dependence on source to board size ratio and top and bottom boundary conditions. It was shown that the thermal conductivities were stronger functions of the source to board size ratio for smaller values of this ratio. This dependence was more pronounced for boards with stronger convection heat transfer on their top side, and for boards with thicker component side copper layer. The thermal conductivities were less sensitive to the variation of the convection heat transfer on the bottom side of the board.

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Lillo, Patricio, i Curran Crawford. "Analysis of Embedded Blade Root Carrot and T-Bolt Connections Subject to Cold Weather Conditions Using a Finite Element Model". W ASME 2010 International Mechanical Engineering Congress and Exposition. ASMEDC, 2010. http://dx.doi.org/10.1115/imece2010-37583.

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Canada has aggressive targets for introducing wind energy across the country, but also faces challenges in achieving these goals due to the harsh Canadian climate. One issue which has received little attention in other countries not experiencing these extremes is the behavior of the composite blades in winter conditions. The scope of this work is to determine and analyze the static stresses on the blade root during operational conditions at extreme cold temperatures. The paper analyses the stresses in the root of the composite blades, specifically two blade-hub connection methods: embedded root carrots and T-bolts. Finite element models of the root are proposed to properly simulate boundary conditions, applied loading and thermal stresses for a 1.5 MW wind turbine. Finally, it is shown that the blade root is strongly affected by the thermal stresses caused by the mismatch and orthotrophy of the coefficients of thermal expansion of the blade root constituents.

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Guo, Xiaofeng, Zhiqiang Guo, Qian Yang i Wei Dong. "Numerical Simulation Model of Electrothermal De-Icing Process on Composite Substrate". W ASME Turbo Expo 2020: Turbomachinery Technical Conference and Exposition. American Society of Mechanical Engineers, 2020. http://dx.doi.org/10.1115/gt2020-16116.

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Abstract A numerical simulation model of electrothermal de-icing process on carbon fiber reinforced polymer (CFRP) composite is conducted to study the effect of thermal properties of the substrate on the ice melting process. A novel melting model which is based on the enthalpy-porosity method is applied to study the transient ice melting process and heat transfer of the de-icing sys-tem. Multi-layered electrothermal de-icing systems including composites with different fiber orientation are used to analyze the effects of orthotropic heat conductivity of the CFRP composite on the ice melting process and heat transfer. Movement of the ice-water interface, the melted zone thickness and the melted zone area on CFRP composite are investigated on the three-dimensional electrothermal de-icing unit. The effects of thermal properties of substrate on the temperature distribution of the ice-airfoil interface are analyzed. The computational results show that the thermal properties of substrates affect the temperature on the ice-airfoil interface, the temperature distribution in the substrate, ice melting area, ice melting rate and ice melting volume significantly. The time that ice starts to melt on the CFRP composite substrate is earlier than that on the metal substrate. However, it takes more time for the ice to melt completely on the ice-CFRP interface than that on the ice-metal inter-face. The orthotropic heat conductivity of CFRP composite results in strong directivity of the melting area on the ice-CFRP in-terface. A ratio parameter is defined to represent the matching degree of substrate materials and geometry model of de-icing system. The simulation model can be applied to study electrothermal de-icing system of nacelle inlet and airfoil made of composite. The results in present work is also helpful to predict the change of temperature during de-icing process and provide guidelines for the optimizing the electrothermal de-icing system to reduce power consumption according to the fiber structure of composite.

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Amabili, M., i M. Pellegrini. "Nonlinear Vibrations of Circular Cylindrical Panels: Theory and Experiments". W ASME 2003 International Mechanical Engineering Congress and Exposition. ASMEDC, 2003. http://dx.doi.org/10.1115/imece2003-55444.

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Large-amplitude (geometrically nonlinear) vibrations of circular cylindrical panels subjected to radial harmonic excitation in the spectral neighborhood of the lowest resonances are investigated. The Donnell’s nonlinear thin-shell theory is used to calculate the elastic strain energy. The formulations is also valid for orthotropic and symmetric cross-ply laminated composite shells; geometric imperfections are taken into account. Comparison of calculations to numerical results available in the literature is also performed. The nonlinear equations of motion are studied by using a code based on arclength continuation method that allows bifurcation analysis. Vibration response of three thin circular cylindrical panels of different materials (stainless steel, copper and composite) to harmonic excitation in the neighborhood of the first three natural frequencies has been measured for different force levels. The experimental boundary conditions approximate (i) on the curved edges: zero radial, axial and circumferential displacements; all rotations were allowed; (ii) on the straight edges: zero radial and axial displacements; all rotations and circumferential displacements were allowed. The different levels of excitation permitted to reconstruct the relatively strong, softening type nonlinearity of the panels.

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Avendano, Raul D., i Dara W. Childs. "One Explanation for 2N Response due to Misalignment in Rotors Connected by Flexible Couplings". W ASME Turbo Expo 2012: Turbine Technical Conference and Exposition. American Society of Mechanical Engineers, 2012. http://dx.doi.org/10.1115/gt2012-68565.

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Misalignment in turbomachinery is commonly thought to produce two-times-running-speed (2N) response. The source of 2N vibration response was investigated, starting with the development of finite-element models for three flexible disc-pack couplings (4-bolt, 6-bolt, and 8-bolt couplings). Parallel and angular misalignments were analyzed. The resultant lateral stiffness terms had 1N, 2N, and 3N harmonic components versus the shaft rotation angle. The 4-bolt coupling had large 1N stiffness components under angular and parallel misalignment. The 6-bolt coupling had only a 1N reaction component under angular misalignment, while parallel misalignment showed a strong 2N reaction component, larger than either the 1N or 3N components. Under angular misalignment, the 8-bolt model produced large 1N reaction components. Under parallel misalignment, it produced 1N, 2N, and 3N components that were similar in magnitude. All the couplings behaved linearly in the range studied. Some experts attribute observed 2N response to nonlinear bearing forces produced by bearings at high unit loads. Static tests for a 5-pad tilting-pad journal bearing with unit loads up to 34.5bars produced small 2N motion components that did not grow with increasing unit load. A Jeffcott-rotor model with shaft stiffness orthotropy and a fixed-direction side load predicts that 2N response depends on three related factors: (1) the degree of orthotropy (the 1N stiffness variation magnitude), (2) the magnitude of the side load, and (3) the relative ratio of running speed to rotor 1st natural frequency, (ω/ωn). The 2N response magnitude is largest when ω is close to ωn/2. The side load is required to create 2N response due to shaft stiffness orthotropy. Misaligned couplings create precisely the same (very old) physical model as a two-pole turbogenerator rotor with a gravity side load (gravity critical speed). The response of a 2-rotor/coupling system with parallel and angular misalignment was simulated using a time-transient code. When the frequency ratio was 0.5, the system response with the 4-bolt and 6-bolt coupling had a synchronous 1N component as well as a significant 2N component. Parallel misalignment at a coupling produces stiffness orthotropy and a fixed-direction side load. For ranges of running speed near ωn/2, these two elements can combine to produce 2N response.

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