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Добірка наукової літератури з теми "I band dynamic stiffness"

Автор: Grafiati

Опубліковано: 10 березня 2023

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Статті в журналах з теми "I band dynamic stiffness"

1

Sun, Yonggan. "Study on the Dynamic Performance of Locally Resonant Plates with Elastic Unit Cell Edges." Mathematical Problems in Engineering 2021 (June 4, 2021): 1–7. http://dx.doi.org/10.1155/2021/5541052.

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A Floquet–Bloch approach is employed to demonstrate the stop bands for an infinite locally resonant plate. In addition, the effects of the connection stiffness of the unit cells on the band gap and dynamic performance of a locally resonant plate are analysed. The results show that the degree of inhibition of elastic waves in the band gaps increases rapidly when the connection stiffness of the unit cells increases within the scope of the transition stage stiffness. However, outside of the range of transition stage stiffness, the degree of inhibition of elastic waves in the band gaps basically remains unchanged. This discovery widens the application scope for vibration and noise control using locally resonant plates.

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2

WANG, BAOSHENG, JIANMIN ZUO, and MULAN WANG. "ANALYSIS AND COMPENSATION OF STIFFNESS IN CNC MACHINE TOOL FEED SYSTEM." Journal of Advanced Manufacturing Systems 10, no. 01 (June 2011): 77–84. http://dx.doi.org/10.1142/s0219686711002004.

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Based on the elastic mechanics theory, the mathematical models of axial stiffness and torsion stiffness are constructed in accordance with single end thrust and two ends thrust. The effects of stiffness on dead band error are analyzed. With the analysis of displacement deviation induced by axial stiffness and angular displacement deflection caused by torsion stiffness, a formula to calculate the dead band error is presented. A model for Computer Numerical Control (CNC) machine tool feed system with stiffness is established. By applying computer simulation, dynamic performances, static performances and steady-state error of the system are analyzed. To reduce the effect of stiffness on the system, the feedforward control method is used to compensate stiffness. The simulation analysis shows the result that dynamic and static performances are improved, as well as steady-state error of the system is reduced by more than 58% with this approach.

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3

Xu, Qiang-Rong, Yang Zhu, Kang Lin, Cheng Shen, and Tian-Jian Lu. "Low-frequency sound insulation performance of novel membrane acoustic metamaterial with dynamic negative stiffness." Acta Physica Sinica 71, no. 21 (2022): 214301. http://dx.doi.org/10.7498/aps.71.20221058.

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For improving the low-frequency sound insulation properties of membrane/plate structures, a new quasi-zero stiffness membrane acoustic metamaterial with dynamic magnetic negative stiffness is proposed. When the equivalent magnetic charge theory is used to investigate the dynamic magnetic negative stiffness, a theoretical model of proposed metamaterial with finite dimension is established based on the Galerkin method. Through a combination of theoretical analysis, numerical simulation and experimental measurement, the low-frequency (1–1000 Hz) sound insulation performance of the metamaterial is investigated from several perspectives, including structural modality, vibration mode, average velocity, phase curve, equivalent mass density, and equivalent spring-mass dynamics model. The results show that at a certain initial membrane tension, the decreasing of the magnetic gap or the increasing of the residual flux density can increase the dynamic magnetic negative stiffness. This in turn leads the peak frequency to decrease and the bandwidth of sound insulation to increase, thus achieving effective low-frequency sound insulation over a wide frequency band. Further, when the magnetic gap is larger than the second critical magnetic gap and smaller than the first critical magnetic gap, the first-order modal resonance of the metamaterial disappears, and the corresponding value of sound insulation valley increases significantly, thus demonstrating superior sound insulation effect in a wide frequency band. The proposed method of using dynamic magnetic negative stiffness to improve low-frequency sound insulation valleys due to modal resonance provides useful theoretical guidance for designing membrane/plate type low-frequency sound insulation metamaterials.

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4

Sun, Ya Zhou, Xue Mei Yu, Hai Tao Liu, and Ying Chun Liang. "Analysis of Dynamic Stiffness and Damping of Partial Porous Aerostatic Thrust Bearings." Applied Mechanics and Materials 16-19 (October 2009): 596–600. http://dx.doi.org/10.4028/www.scientific.net/amm.16-19.596.

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Porous materials have been successfully used in an aerostatic bearing. In this paper, the dynamic stiffness and damping of partial porous aerostatic thrust bearings are analyzed by numerical calculation method. Firstly, the pressure distribution function of the bearing is divided into the static and dynamic pressure distribution functions through minor perturbation method. Then, the static and dynamic pressure distribution functions are calculated by FEM. Finally, the dynamic stiffness and damping coefficients of the bearing are solved. The result indicates that the dynamic stiffness increases obviously with the increment of supply pressure and first increases then decreases with the increment of frequency, and that there is negative damping in the low frequency band and the supply pressure has a great impact on the stability of the bearing.

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5

Ding, Lan, Zhi Ye, and Qiao-Yun Wu. "Flexural vibration band gaps in periodic Timoshenko beams with oscillators in series resting on flexible supports." Advances in Structural Engineering 23, no. 14 (June 16, 2020): 3117–27. http://dx.doi.org/10.1177/1369433220928529.

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The propagation properties of waves in Timoshenko beams resting on flexible supports and with periodically attached harmonic locally resonant oscillators are studied by the transfer matrix methodology. Through calculating the differential equations of the beam for the flexible vibration and the dynamic equations of the oscillators in series, the matrix of dynamic stiffness and the resulting transfer matrix are derived. Accordingly, the band gap in infinite system characterized by the propagation constant can be verified by comparing to the curve of transmission property, determined with the finite element method for the finite system. The mechanism of each band gap formation is further explored. Numerical results show that different from the single degree-of-freedom mass-spring model, one more locally resonant band gap is generated in the system of two oscillators in series. The introduction of flexible supports, allowing for variable internal coupling between the adjacent cells, produces an extra band gap with a minimum frequency of zero. It is also found that the starting frequencies of the locally resonant gaps are related to the spring stiffness and mass of the oscillator. Therefore, the positions and widths of the band gaps can be tuned by properly adjusting the four parameters of the oscillators and also the stiffness of the flexible supports.

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6

Esteva, Luis. "Nonlinear Seismic Response of Soft-First-Story Buildings Subjected to Narrow-Band Accelerograms." Earthquake Spectra 8, no. 3 (August 1992): 373–89. http://dx.doi.org/10.1193/1.1585686.

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The nonlinear dynamic response of shear systems representative of buildings with excess stiffness and strength at all stories above the first one is studied. Variables covered were number of stories, fundamental period, along-height form of variation of story stiffness, ratio of post-yield to initial stiffness, in addition to the variable of primary interest: the factor r, expressing the ratio of the average value of the safety factor for lateral shear at the upper stories to that at the bottom story. The lateral strength at the latter was taken as equal to the nominal value of the corresponding story shear computed by conventional modal dynamic analysis for the design spectrum specified by Mexico City seismic design regulations of 1987 for a seismic behavior (ductility) reduction coefficient of 4.0. The excitation was in some cases the EW component of the accelerogram recorded at the parking lot of the Ministry of Communications and Transport in the same city during the destructive earthquake of September 19, 1985, and in some other cases an ensemble of artificial accelerograms with similar statistical properties. It is concluded that the nonlinear seismic response of shear buildings whose upper stories have lateral strengths and stiffnesses which correspond to safety factors larger than those applied to the first story is very sensitive to the relation between the average of the over-strength factors at the upper stories and that at the first one, as well as to the ratio of post-yield to initial stiffnesses. The nature and magnitude of the influence of r on the maximum ductility demands at the first story depend on the low-strain fundamental natural period of the system. The ductility demands computed for elastoplastic systems may in some cases be extremely large. Accounting for P-delta effects leads to an enhancement of the sensitivity of the response with respect to r.

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7

Qin, Zhaoye, Delin Cui, Shaoze Yan, and Fulei Chu. "Application of 2D finite element model for nonlinear dynamic analysis of clamp band joint." Journal of Vibration and Control 23, no. 9 (August 3, 2015): 1480–94. http://dx.doi.org/10.1177/1077546315594065.

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Due to frictional slippage between the joint components, clamp band joints may generate nonlinear stiffness and friction damping, which will affect the dynamics of the joint structures. Accurate modeling of the frictional behavior in clamp band joints is crucial for reliable estimation of the joint structure dynamics. While the finite element (FE) method is a powerful tool to analyze structures assembled with joints, it is computationally expensive and inefficient to perform transient analyses with three-dimensional (3D) FE models involving contact nonlinearity. In this paper, a two-dimensional (2D) FE model of much more efficiency is applied to investigate the dynamics of a clamp band jointed structure subjected to longitudinal base excitations. Prior to dynamic analyses, the sources of the model inaccuracy are determined, upon which a two-step model updating technique is proposed to improve the accuracy of the 2D model in accordance with the quasi-static test data. Then, based on the updated 2D model, the nonlinear influence of the clamp band joint on the dynamic response of the joint structure is investigated. Sine-sweep tests are carried out to validate the updated 2D FE model. The FE modeling and updating techniques proposed here can be applied to other types of structures of cyclic symmetry to develop accurate model with high computational efficiency.

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8

Wang, Yong, Shunming Li, Chun Cheng, and Xingxing Jiang. "Dynamic Analysis of a High-Static-Low-Dynamic-Stiffness Vibration Isolator with Time-Delayed Feedback Control." Shock and Vibration 2015 (2015): 1–19. http://dx.doi.org/10.1155/2015/712851.

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This paper proposes the time-delayed cubic velocity feedback control strategy to improve the isolation performance of High-Static-Low-Dynamic-Stiffness (HSLDS) vibration isolator. Firstly, the primary resonance of the controlled HSLDS vibration isolator is obtained by using multiple scales method. The equivalent damping ratio and equivalent resonance frequency are defined to study the effects of feedback gain and time delay on the primary resonance. The jump phenomenon analysis of the controlled system without and with time delay is investigated by using Sylvester resultant method and optimization method, respectively. The stability analysis of the controlled system is also considered. Then, the 1/3 subharmonic resonance of the controlled system is studied by using multiple scales method. The effects of feedback gain and time delay on the 1/3 subharmonic resonance are also presented. Finally, force transmissibility is proposed to evaluate the performance of the controlled system and compared with an equivalent linear passive vibration isolator. The results show that the vibration amplitude of the controlled system around the resonance frequency region decreases and the isolation frequency band is larger compared to the equivalent one. A better isolation performance in the high frequency band can be achieved compared to the passive HSLDS vibration isolator.

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9

Solaroli, G., Z. Gu, A. Baz, and M. Ruzzene. "Wave Propagation in Periodic Stiffened Shells: Spectral Finite Element Modeling and Experiments." Journal of Vibration and Control 9, no. 9 (September 2003): 1057–81. http://dx.doi.org/10.1177/107754603030677.

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The capability of periodic structures to act as filters for propagating waves is used to control the propagation of waves in thin shells. The shells are stiffened by periodically placed rings in order to generate periodic discontinuities in the stiffness and inertial spatial distribution along the longitudinal axes of these shells. Such discontinuities result in attenuation of the wave propagation over certain frequency bands called stop bands. A distributed-parameter approach is used to derive a spectral finite element model of the periodically stiffened shell. The model accurately describes the dynamic behavior of the shell using a small number of elements. The stiffening rings, modeled using the curved beam theory, are considered as lumped elements whose mass and stiffness matrices are combined with those of the shell. The resulting dynamic stiffness matrix of the ring-stiffened shell element is used to predict the wave propagation dynamics in the structure. In particular, the shell propagation constants are determined by solving a polynomial eigenvalue problem, as a numerically robust alternative to the traditional transfer matrix formulation. The study of the propagation constants shows that the discontinuity introduced by the stiffeners generates the typical stop/pass band pattern of periodic structures. The location and width of the stop bands depend on the spacing and geometrical parameters of the rings. The existence of the stop bands, as predicted from the analysis of the propagation constants, is verified experimentally. Excellent agreement between theoretical predictions and experimental results is achieved. The presented theoretical and experimental techniques provide viable means for designing periodically stiffened shells with desired attenuation and filtering characteristics.

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10

Li, Jun Lan, Shao Ze Yan, and Xue Feng Tan. "Modeling and Simulation of Clamp Band Dynamic Envelope in a LV/SC Separation System." Applied Mechanics and Materials 141 (November 2011): 359–63. http://dx.doi.org/10.4028/www.scientific.net/amm.141.359.

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The clamp band system is a typical locked and separated device of the launch vehicle (LV) / the spacecraft (SC), and its release-separation process is one of the important factors that affect the LV/SC separation movement. A nonlinear spring-damper model was employed to describe the contact-impact behavior between the V-segment of the clamp band and the LV/SC interface, and lumped mass method was used to depict the clamp band. By using ADAMS, a dynamic model of the clamp band system was established. The simulation results show that the impulse of the explosive bolts and the stiffness of lateral-restraining springs have significant effects on the clamp band dynamic envelope. The shock of the satellite-vehicle separation is very vulnerable to the clamp band pretension and the friction coefficient between the V-segment and the LV/SC interface.

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Дисертації з теми "I band dynamic stiffness"

1

周婉娥 and Wan-E. Zhou. "The dynamic stiffness method." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 1996. http://hub.hku.hk/bib/B31235487.

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2

Leung, A. Y. T. "Dynamic stiffness and substructures." Thesis, Aston University, 1993. http://publications.aston.ac.uk/21737/.

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3

Zhou, Wan-E. "The dynamic stiffness method /." Hong Kong : University of Hong Kong, 1996. http://sunzi.lib.hku.hk/hkuto/record.jsp?B19668612.

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4

Alley, Ferryl. "Dynamic ankle stiffness during upright standing." Thesis, McGill University, 2012. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=110417.

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Studies of upright stance commonly model its biomechanics as an inverted pendulum, defining an overall postural stiffness, generated by the ankle joints, needed to overcome gravity's destabilizing effects. This model assumes symmetric left and right ankle stiffness, fixed throughout upright stance. However, the relative contributions of the intrinsic and reflex components of dynamic stiffness and how lower limbs interact during upright standing is not well understood. This thesis estimated the dynamic stiffness in both ankles simultaneously during upright standing and examined coordination between the two limbs. During bilateral perturbation trials, where angular position perturbations were applied to both ankles simultaneously, a strong intrinsic and reflex response was observed. For all subjects, intrinsic stiffness was lower than the required postural stiffness to maintain standing. Dynamic ankle stiffness also changed for different levels of postural sway torque, such that intrinsic and reflex stiffness was higher during forward lean and lower when leaning back. Contralateral responses were observed between input ankle position and the torques generated from the opposite ankle. These findings suggest that the overall postural control is not a simple summation of independent, fixed intrinsic stiffness responses from individual ankles. Intrinsic elastic stiffness is not sufficient for maintaining balance and contributing stiffness pathways are modulated throughout upright standing sway. Upright standing models must incorporate dynamic ankle stiffness measurements, variable stiffness parameters, and interactions between each supporting limbs.
Les études de la posture érigée sont couramment fondées sur le modèle biomécanique du pendule inversé définissant une raideur posturale générale produite par les articulations des chevilles et nécessaire pour compenser les effets déstabilisants de la gravité. Ce modèle est basé sur l'hypothèse d'une raideur symétrique des chevilles gauche et droite qui demeure fixe pendant la tenue de la posture érigée. Toutefois, les contributions relatives des composantes intrinsèques et réflexes de la raideur dynamique ainsi que l'interaction des membres inférieurs pendant la position érigée debout ne sont pas bien comprises. Ce mémoire fait état d'une estimation de la raideur dynamique des deux chevilles simultanément durant la position érigée debout, ainsi que d'une étude de la coordination entre les deux membres. Au cours de tests de perturbation bilatérale, pendant lesquels des perturbations de la position angulaire ont été appliquées aux deux chevilles simultanément, une nette réponse intrinsèque et réflexe a été observée. Chez tous les sujets, la raideur intrinsèque était inférieure à la raideur posturale nécessaire pour maintenir la station debout. La raideur dynamique des chevilles a également évolué en fonction de différents niveaux du couple du balancement postural, de telle sorte que la raideur intrinsèque et réflexe était plus élevée pendant l'inclinaison avant et moins élevée pendant l'inclinaison arrière. Des réponses controlatérales ont été observées entre la position de départ de la cheville et les couples générés depuis la cheville opposée. Ces résultats donnent à penser que le contrôle postural général ne consiste pas en la simple sommation de réponses indépendantes fixes de raideur intrinsèque des chevilles individuelles. La raideur élastique intrinsèque ne suffit pas pour maintenir l'équilibre, et les voies de raideur contributives sont modulées pendant le balancement de la position érigée debout. Les modèles de la position érigée debout doivent intégrer des mesures de la raideur dynamique des chevilles, des paramètres variables de la raideur et des interactions entre les membres d'appui.

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5

郭騰川 and Tang-chuen Nick Kwok. "Dynamic stiffness method for curved structures." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 1995. http://hub.hku.hk/bib/B31212359.

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6

Kwok, Tang-chuen Nick. "Dynamic stiffness method for curved structures /." Hong Kong : University of Hong Kong, 1995. http://sunzi.lib.hku.hk/hkuto/record.jsp?B19672421.

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7

Vega, González Myraida Angélica. "Dynamic study of tunable stiffness scanning microscope probe." Thesis, Massachusetts Institute of Technology, 2005. http://hdl.handle.net/1721.1/32967.

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Thesis (S.B.)--Massachusetts Institute of Technology, Dept. of Mechanical Engineering, 2005.
Includes bibliographical references (leaf 31).
This study examines the dynamic characteristics of the in-plane tunable stiffness scanning microscope probe for an atomic force microscope (AFM). The analysis was carried out using finite element analysis (FEA) methods for the micro scale device and its macro scale counterpart, which was designed specifically for this study. Experimental system identification testing using sound wave and high-speed camera recordings was clone on the macro scale version to identify trends that were then verified in the micro scale predictions. The results for the micro scale device followed the trends predicted by the macro scale experimental data. The natural frequencies of the device corresponded to the three normal directions of motion, in ascending order from the vertical direction, the out-of- plane direction, and the horizontal direction. The numerical values for these frequencies in the micro scale are 81.314 kHz, 51.438 kHz, and 54.899 kHz for the X, Y, and Z directions of vibration respectively. The error associated with these measurements is 6.6% and is attributed to the high tolerance necessary for measurements in the micro scale, which was not matched by the macro scale data acquisition methods that predict the natural frequency range.
(cont.) The vertical vibrations are therefore the limiting factor in the scanning speed of the probe across a sample surface, thus requiring the AFM to scan at an effective frequency of less than 81.3 kHz to avoid resonance.
by Myraida Angélica Vega González.
S.B.

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8

Garcia, Maria-José. "Engineering rubber bushing stiffness formulas including dynamic amplitude dependence." Licentiate thesis, KTH, Aeronautical and Vehicle Engineering, 2006. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-4017.

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Engineering design models for the torsion and axial dynamic stiffness of carbon black filled rubber bushings in the frequency domain including amplitude dependence are presented. They are founded on a developed material model which is the result of applying a separable elastic, viscoelastic and friction rubber component model to the material level. Moreover, the rubber model is applied to equivalent strains of the strain states inside the torsion or axial deformed bushing previously obtained by the classical linear theory of elasticity, thus yielding equivalent shear moduli which are inserted into analytical formulas for the stiffness. Therefore, unlike other simplified approaches, this procedure includes the Fletcher-Gent effect inside the bushing due to non-homogeneous strain states. The models are implemented in Matlab®. In addition, an experimental verification is carried out on a commercially available bushing thus confirming the accuracy of these models which become a fast engineering tool to design the most suitable rubber bushing to fulfil user requirements. Finally, they can be easily employed in multi-body and finite element simulations

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9

Garcia, Maria-José. "Engineering rubber bushing stiffness formulas including dynamic amplitude dependence /." Stockholm : Royal Institute of Technology, 2006. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-4017.

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10

Carrella, Alessandro. "Passive vibration isolators with high-static-low-dynamic-stiffness." Thesis, University of Southampton, 2008. https://eprints.soton.ac.uk/51276/.

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In many engineering applications there is need to reduce the level of vibrations that are transmitted from a source to a receiver. Amongst several different techniques, the most commonly adopted solution is to interpose an isolation mount between the source and the receiver. Ideally, a vibration isolation mount would have a high static stiff- ness to prevent too large a static displacement to occur, but a low dynamic stiffness which reduces the natural frequency and extends the frequency range of isolation. For linear mounts these two features are mutually exclusive. However, an improved com- promise can be reached by employing nonlinear mounts. In this thesis the advantages and the limitations of nonlinear isolation mechanisms with a high-static-low-dynamic- stiffness(HSLDS) characteristic are investigated. A study of the static characteristics of two mechanisms with HSLDS is presented. This desired property is obtained by connecting in parallel elements with positive and negative stiffness. For both systems the positive stiffness is given by linear springs. In one model the geometry of the system is exploited to achieve the desired negative stiffness. This is obtained by a pair of linear springs placed at a certain angle to the horizontal (oblique springs). In the second model considered the required negative stiffness is provided by a set of magnets in attracting configuration. In both cases the force and stiffness are approximated to a symmetric cubic polynomial and a quadratic function of the displacement respectively. From a dynamical point of view this allows the system to be treated as a Duffing oscillator. It is argued that for small oscillations about the static equilibrium position the mechanism behaves linearly. A lab-scale rig which reproduces the HSLDS system with magnets and springs is designed and built. The excitation level is chosen to comply with the assumption of small displacement so that the experimental results show that the system responds in a rather linear fashion. The natural frequency of the HSLDS is half that of a linear model with the same static displacement and its transmissibility also compares favourably. A nonlinear analysis is also carried out in order to predict the response of the system when the assumption of linearity no longer holds true. Both cases of harmonic excita- tion of the payload and of the base are studied. For the two instances an approximate solution to the nonlinear equation of motion is found by applying the method of Har- monic Balance to a first order expansion. The main feature of the dynamic response of a Duffing oscillator is the jump phenomenon. Herein this is described and analyt- ical expressions for the jump frequencies are also provided. The isolation properties of an HSLDS isolation system are evaluated in terms of the transmissibility and its performance is compared with that of an equivalent linear system. It is shown that the HSLDS has a higher isolation capability.

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Книги з теми "I band dynamic stiffness"

1

Leung, Andrew Y. T. Dynamic Stiffness and Substructures. London: Springer London, 1993. http://dx.doi.org/10.1007/978-1-4471-2026-1.

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2

Leung, Andrew Y. T. Dynamic Stiffness and Substructures. London: Springer London, 1993.

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3

Dynamic stiffness and substructures. London: Springer-Verlag, 1993.

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4

Pedro, Arduino, University of Washington. Dept. of Civil Engineering., Washington State Transportation Center, Washington (State). Dept. of Transportation., United States. Federal Highway Administration., and Washington State Transportation Commission, eds. Dynamic stiffness of piles in liquefiable soils. Seattle, Wash: The Center, 2002.

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5

Markworth, Wayne. The dynamic marching band. [S.l.]: Accent Publications, 2008.

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6

United States. National Aeronautics and Space Administration., ed. Experiments on dynamic stiffness and damping of tapered bore seals. [Washington, DC: National Aeronautics and Space Administration, 1987.

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7

K, Ghosh A. Evaluation of dynamic stiffness and damping factor of a hydraulic damper. Mumbai: Bhabha Atomic Research Centre, 2000.

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8

Vanderborght, Bram. Dynamic Stabilisation of the Biped Lucy Powered by Actuators with Controllable Stiffness. Berlin, Heidelberg: Springer Berlin Heidelberg, 2010. http://dx.doi.org/10.1007/978-3-642-13417-3.

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9

Vanderborght, Bram. Dynamic stabilisation of the biped Lucy powered by actuators with controllable stiffness. Berlin: Springer, 2010.

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10

Townsend, John S. Dynamic characteristics of a vibrating beam with periodic variation in bending stiffness. [Washington, D.C.]: National Aeronautics and Space Administration, Scientific and Technical Information Branch, 1987.

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Частини книг з теми "I band dynamic stiffness"

1

Leung, Andrew Y. T. "Dynamic Stiffness." In Dynamic Stiffness and Substructures, 133–88. London: Springer London, 1993. http://dx.doi.org/10.1007/978-1-4471-2026-1_4.

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2

Leung, Andrew Y. T. "Dynamic Substructures." In Dynamic Stiffness and Substructures, 53–132. London: Springer London, 1993. http://dx.doi.org/10.1007/978-1-4471-2026-1_3.

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3

Mukhopadhyay, Madhujit. "Dynamic Direct Stiffness Method." In Structural Dynamics, 395–423. Cham: Springer International Publishing, 2021. http://dx.doi.org/10.1007/978-3-030-69674-0_10.

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4

Leung, Andrew Y. T. "Harmonic Analysis." In Dynamic Stiffness and Substructures, 1–19. London: Springer London, 1993. http://dx.doi.org/10.1007/978-1-4471-2026-1_1.

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5

Leung, Andrew Y. T. "Finite Elements and Continuum Elements." In Dynamic Stiffness and Substructures, 21–51. London: Springer London, 1993. http://dx.doi.org/10.1007/978-1-4471-2026-1_2.

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6

Leung, Andrew Y. T. "General Formulation." In Dynamic Stiffness and Substructures, 189–240. London: Springer London, 1993. http://dx.doi.org/10.1007/978-1-4471-2026-1_5.

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7

Hagedorn, Peter, Klaus Kelkel, and Jörg Wallaschek. "Dynamic stiffness of rectangular plates." In Lecture Notes in Engineering, 28–144. Berlin, Heidelberg: Springer Berlin Heidelberg, 1986. http://dx.doi.org/10.1007/978-3-642-82906-2_3.

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8

Connor, Jerome, and Simon Laflamme. "Optimal Stiffness/Damping for Dynamic Loading." In Structural Motion Engineering, 75–140. Cham: Springer International Publishing, 2014. http://dx.doi.org/10.1007/978-3-319-06281-5_3.

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9

Lepert, P., and J. L. Briaud. "Dynamic non destructive testing of footing stiffness." In Structural Dynamics, 237–43. London: Routledge, 2022. http://dx.doi.org/10.1201/9780203738085-35.

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10

Ling, Mingxiang. "Building Dynamic Stiffness Matrix Library of Flexure Members for Use in a Dynamic Stiffness Model of Compliant Mechanisms." In Advances in Mechanism and Machine Science, 469–78. Cham: Springer International Publishing, 2019. http://dx.doi.org/10.1007/978-3-030-20131-9_47.

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Тези доповідей конференцій з теми "I band dynamic stiffness"

1

Gholipour, Yaghob. "Dynamic Buckling Analysis of Axi-Symmetric Shells." In ASME 7th Biennial Conference on Engineering Systems Design and Analysis. ASMEDC, 2004. http://dx.doi.org/10.1115/esda2004-58210.

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Анотація:

In the field of dynamic buckling analysis of shell structures, the effect of vibration on buckling load and the effect of axial loads on vibration are very interesting phenomena. In this work the finite element method has been applied for dynamic buckling analysis of axi-symmetric shell. The degenerated axi-symmetric shell element and subspace iteration technique has been used to carry out the analysis. The stiffness matrix is stored in band form to have efficient memory management and the 3 × 3 gauss quadrature has been used for calculation of element stiffness matrix and consistent load vector. An attempt is made to study the effect of static in-plane edge loads on the fundamental frequency of axi-symmetric shells. The effect of vibration at a prescribed frequency on the buckling behavior of shell is also investigated. From the limited analysis carried out, it is found that the presence of static in-plane edge loads considerably affects the natural frequency and hence necessitates the evaluation of appropriate natural frequency and mode shapes for use in realistically carrying out the dynamic response analysis of structures subjected to forced vibration by mode superposition method.

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2

Fricke, J. Robert, and Mark A. Hayner. "Direct Global Stiffness Matrix Method for 3-D Truss Dynamics." In ASME 1995 Design Engineering Technical Conferences collocated with the ASME 1995 15th International Computers in Engineering Conference and the ASME 1995 9th Annual Engineering Database Symposium. American Society of Mechanical Engineers, 1995. http://dx.doi.org/10.1115/detc1995-0402.

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Abstract This paper deals with the acoustical design goal for a new approach in submarine architecture calling for the use of an internal truss to support the ship’s control and living spaces in the forward section. The acoustical design goal is to minimize truss vibration over a broad band of frequency through the application of passive damping treatments. Damping can be placed in three generic locations: 1) in or along the truss members, 2) in the joints between members, and 3) in dynamic absorbers placed at discrete locations along the truss members. This paper develops the framework for evaluating ways to achieve the stated acoustical goal. We outline the formulation of the Direct Global Stiffness Matrix method (DGSM), which is used to relate externally applied forces and moments at truss joints to joint displacements everywhere on the truss. The model is kinematically constrained by matching welded boundary conditions at the joints, and the joint displacements are computed by a sparse matrix inversion method. From these displacements, wave amplitudes for each of the three wave types, longitudinal, torsional, and flexural, may be computed on any of the beam members. An example of the use of this method illustrates the sensitivity of the global energy decay rate to the truss damping parameters, which are the only free parameters of the model. [Work sponsored by ARPA/ONR]

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3

Lee, Usik, and Joohong Kim. "Modal Spectral Element for the Transverse Vibrations of Axially Moving Wide-Band Strips." In ASME 2002 International Design Engineering Technical Conferences and Computers and Information in Engineering Conference. ASMEDC, 2002. http://dx.doi.org/10.1115/detc2002/cie-34469.

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The use of frequency-dependent spectral element matrix (or dynamic stiffness matrix) in structural dynamics is known to provide very accurate solutions, while reducing the number of degrees-of-freedom to resolve the computational and cost problems. Thus, in the present paper, the modal spectral element is formulated for thin plates moving with constant speed under a uniform in-plane axial tension. The concept of Kantorovich method is used to formulate the modal spectral element matrix in frequency-domain. The present modal spectral element is then evaluated by comparing its solutions with exact analytical solutions and FEM solutions. The effects of the moving speed and the in-plane tension on the dynamic characteristics of a moving plate are numerically investigated.

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4

Dwivedi, Ankur, Arnab Banerjee, and Bishakh Bhattacharya. "Dynamics of Piezo-Embedded Negative Stiffness Mechanical Metamaterials: A Study on Electromechanical Bandgaps." In ASME 2020 International Mechanical Engineering Congress and Exposition. American Society of Mechanical Engineers, 2020. http://dx.doi.org/10.1115/imece2020-23717.

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Abstract Dynamics of periodic materials and structures have a profound historic background starting from Newton’s first effort to find sound propagation in the air to Rayleigh’s exploration of continuous periodic structures. This field of interest has received another surge from the early 21st century. Elastic mechanical metamaterials are the exemplars of periodic structures that exhibit interesting frequency-dependent properties like negative Young’s modulus, negative mass and negative Poisson’s ratio in a specific frequency band due to additional feature of local resonance. In this research, we present the modeling of piezo-embedded negative stiffness metamaterials by considering a shunted inductor energy harvesting circuit. For a chain of a finite number of metamaterial units, the coupled equation of motion of the system is deduced using generalized Bloch’s theorem. Successively, the backward substitution method is applied to compute harvested power and the transmissibility of the system. Additionally, through the extensive non-dimensional study of this system, the proposed metamaterial band structure is investigated to perceive locally resonant mechanical and electromechanical bandgaps. The results explicate that the insertion of the piezoelectric material in the resonating unit provides better tun-ability for vibration attenuation and harvested energy.

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5

Murer, Mauro, Walter Lacarbonara, and Giovanni Formica. "Multi-Stop Band Wave Propagation in a Honeycomb Metamaterial With Embedded Resonators." In ASME 2022 International Design Engineering Technical Conferences and Computers and Information in Engineering Conference. American Society of Mechanical Engineers, 2022. http://dx.doi.org/10.1115/detc2022-91070.

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Abstract This work discusses the stop-band propagation properties of a honeycomb metamaterial hosting a periodic arrangement of highly tunable, infinite-dimensional resonators. The cellular material system architecture takes inspiration from lightweight honeycombs — due to their inherent periodicity, high flexural/shear stiffness — which host resonators with lumped masses exhibiting infinitely many frequencies and modes. These resonators are designed to possess high dynamic resilience and frequency/damping tunability. In the present work, two resonator architectures are investigated and compared, namely, (i) a cantilever with a tip mass, (ii) a spider-web-like structure with a central mass. Contrary to traditional approaches making use of discrete spring-mass-damper resonators, here the infinite-dimensional resonators are intentionally tailored for their potential of generating, in principle, infinitely many band gaps. The nondimensional dispersion curves are obtained via the Plane Wave Expansion method. By retaining the lowest modes of the two investigated resonators designs, the outcomes show the appearance of multiple band gaps whose bandwidth and central frequency depend on the mass ratio and the nondimensional stiffness of the resonators. Preliminary experimental results based on laser scanning vibrometry, and conducted on 3D printed honeycomb samples, corroborate the theoretical model and predictions.

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6

Kang, Hooi-Siang, Moo-Hyun Kim, Shankar S. Bhat Aramanadka, and Heon-Yong Kang. "Dynamic Response Control of Top-Tension Risers by a Variable Damping and Stiffness System With Magneto-Rheological Damper." In ASME 2014 33rd International Conference on Ocean, Offshore and Arctic Engineering. American Society of Mechanical Engineers, 2014. http://dx.doi.org/10.1115/omae2014-23683.

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The exploration and extraction of offshore hydrocarbon is currently facing stricter requirements in environmental conditions, structural integrity, and dynamic performance. Vibration control may be a critical part of mitigating the excessive dynamic responses of the offshore floating structures. If the structural responses can be monitored and controlled, then smart-platform technology can greatly widen the applicability of current technology toward deeper waters and more severe environmental conditions. This paper is focusing on the numerical simulations and analyses of top-tension risers in a tension-leg platform (TLP), incorporated with a bang-bang controlled magneto-rheological (MR) damper and variable stiffness (VS) system. The specific characteristics of the innovative system in alternating the damping forces and system stiffness show great potential to interactively change the structural behaviors corresponding to various external loadings. This research is expected to provide a robust and cost-effective solution for greatly expanding the capability of future smart offshore-platform technology.

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7

Sampath, Arun M., C. Nataraj, and H. Ashrafiuon. "Optimal Design of Coupled Structures Subjected to Random Excitation." In ASME 1995 Design Engineering Technical Conferences collocated with the ASME 1995 15th International Computers in Engineering Conference and the ASME 1995 9th Annual Engineering Database Symposium. American Society of Mechanical Engineers, 1995. http://dx.doi.org/10.1115/detc1995-0043.

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Abstract This paper presents optimization of the response of coupled structures subjected to random excitation. The dynamic system involves discrete and continuous models of coupled structures. The structures are assumed to be subjected to white noise excitation of known power spectral density. The mean square response of the structure is taken as the objective function. The physical properties such as length, thickness, stiffness and damping are taken as the design variables. The discrete system is assumed to be subjected to two kinds of excitation; band-limited white noise excitation and ideal white noise excitation. Coupling stiffness and damping characteristics are used as design variables. For the case of continuous coupled beam model, band-limited white noise excitation is considered and the root mean square response of the structure is minimized for a range of excitation frequency. Geometric properties of the structure are used as design variables.

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8

Chae, Seokyong, Moustafa El-Gindy, Mukesh Trivedi, Inge Johansson, and Fredrik O¨ijer. "Dynamic Response Predictions of a Truck Tire Using Detailed Finite Element and Rigid Ring Models." In ASME 2004 International Mechanical Engineering Congress and Exposition. ASMEDC, 2004. http://dx.doi.org/10.1115/imece2004-61111.

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A detailed nonlinear finite element (FE) model of a radial-ply truck tire has been developed using an explicit FE code, PAM-SHOCK. The tire model was constructed to its extreme complexity with three-dimensional solid, layered membrane, and beam elements. In addition to the tire model itself, a rim model was included and rotated with the tire with proper mass and rotational inertial effects. The predicted tire responses, such as vertical stiffness, cornering force, and aligning moment, correlated very well to physical measurements. For complete vehicle simulations, a faster and simplified tire model is required for efficient analysis through-put. The behavior of such a tire model can be verified and improved by comparing responses with the developed FE model. Moreover, the parameters needed for the simplified model can be determined by the developed model instead of having to rely on tire measurements. The in-plane sidewall transitional stiffness and damping constants of the FE tire model were determined by rotating the tire on a cleat-drum. The other constants, such as in-plane rotational stiffness and damping constants, were determined by applying and releasing a tangential force on the rigid tread band of the FE tire model. The tire axle, spindle, and reaction force histories at longitudinal and vertical directions were recorded. In addition, the FFT algorithm was applied to examine the transient response in frequency domain. The tire steering characteristics were also determined. These parameters were used as input for a simplified rigid ring tire model. This study will discuss the results obtained from both the developed tire and the rigid ring tire models while both models are rolling at 12 mph constant linear speed and loading range of 13,345 N (3,000 lbs) to 53,378 N (12,000 lbs). The dynamic responses for the developed FE tire model were compared with the dynamics predicted using the rigid ring model. The results will show a successful attempt to capture the transient response of a tire rolling over a complex road profile.

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9

Raclot, J. P., and P. Velex. "Analysis of Dynamic Couplings in Two-Stage Geared Systems." In ASME 1999 Design Engineering Technical Conferences. American Society of Mechanical Engineers, 1999. http://dx.doi.org/10.1115/detc99/vib-8107.

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Abstract A modular model for the simulation of the dynamic behavior of multi-stage spur and helical gears is presented. It is mostly based on shaft finite elements combined with some specific gear elements which account for torsional-flexural-axial couplings, parametric and external excitations. Each tooth contact on theoretical base planes is assimilated to a line contact and discretized in accordance with the contact line evolutions when pinions and gears are rotating. A local stiffness and a normal deviation which represent gear tooth elasticity and tooth shape modifications or/and errors are associated with each cell of the time-dependent grid. Seeking particular stable solutions only, the equations of motion are linearized and solved by using a specific spectral method which has been adapted to parametrically excited systems submitted to broad band parametric and external excitations. Numerical simulations (dynamic transmission errors and displacements) have been performed for two different two-stage geared trains, i. e., a dual speed reducer (two pinion-gear pairs) and a dual mesh reverse idler (3 gears). The role and the definition of profile modifications (short/long reliefs), the contributions of pitch errors and the influence of the mesh relative orientation on the system dynamic behavior are examined. Finally, the nature and the intensity of the inter-mesh couplings in a double stage geared unit are discussed.

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10

Cheng, Yuping, and Teik C. Lim. "Dynamic Analysis of High Speed Hypoid Gears With Emphasis on Automotive Axle Noise Problem." In ASME 1998 Design Engineering Technical Conferences. American Society of Mechanical Engineers, 1998. http://dx.doi.org/10.1115/detc98/ptg-5784.

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Abstract Hypoid gear whine problems in right-angle driveline components mainly used in rear and all-wheel drive vehicles have frequently posed major concerns in automotive industry. Narrow frequency-band response peaks from the rear axle component at mesh frequency and its harmonics tend to generate high-cost warranty issue and consumer dissatisfaction. In order to develop low noise and vibration geared rotor system, one must have better understanding of the dynamic behavior of these high speed non-parallel precision gears. Hence, it is the objective of this paper to develop a 3-dimensional coupled torsional and translational vibratory model of a generic hypoid gear pair by also taking into account the effect of global driveline system dynamics. In this analytical model, the effective mesh point is assumed to be at the theoretical mean pitch location. Its coordinate and corresponding tooth contact normal vector are determined analytically by applying the theory of hypoid gear kinematics. The resultant formulations for the mesh point and line of action are then incorporated into a dynamic model for a right-angle geared rotor system assuming time-invariant mesh stiffness. The proposed model is used to predict the system modal characteristics and dynamic response due to transmission error excitation for various boundary and operating conditions. A limited set of parametric design studies is also performed to analyze the effects of pinion offset, spiral angle and pinion shaft compliance on torsional and translational vibration response.

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Звіти організацій з теми "I band dynamic stiffness"

1

Goodwin, M. J., and M. P. Roach. Vibration Control in Rotating Machinery Using Variable Dynamic Stiffness Squeeze-Films. Fort Belvoir, VA: Defense Technical Information Center, June 1988. http://dx.doi.org/10.21236/ada202902.

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2

Roach M. J. /Goodwin, M. P. Vibration Control in Rotating Machinery Using Variable Dynamic Stiffness Squeeze-Films. Volume 1. Fort Belvoir, VA: Defense Technical Information Center, March 1986. http://dx.doi.org/10.21236/ada174417.

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3

Goodwin, M. J., and M. P. Roach. Vibration Control in Rotating Machinery Using Variable Dynamic Stiffness Squeeze Films. Volume 2. Fort Belvoir, VA: Defense Technical Information Center, March 1986. http://dx.doi.org/10.21236/ada174433.

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4

Song, Chang-Yong, Jae-Yoon Jung, Yong-Sung Kim, Jung-Hwan Lim, and Jong-Chan Park. The Topology and Size Optimization of Bus Roof Structure Considering the Dynamic Stiffness Characteristics. Warrendale, PA: SAE International, May 2005. http://dx.doi.org/10.4271/2005-08-0015.

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5

Bennett, J. G., P. Goldman, D. C. Williams, and C. R. Farrar. A comparison of the dynamic stiffness of the Goldcrown GC-500 grinding machine for three slide designs. Office of Scientific and Technical Information (OSTI), January 1994. http://dx.doi.org/10.2172/10121869.

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6

Lane, Richard. Feasibility Study of Dynamic Built-In Test/Simulation (DBITS) Using Synthetic In-Band Visible/IR Scenes. Fort Belvoir, VA: Defense Technical Information Center, June 1998. http://dx.doi.org/10.21236/ada347278.

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7

Mason, J. J., A. J. Rosakis, and G. Ravichandran. Full Field Measurements of the Dynamic Deformation Field Around a Growing Adiabatic Shear Band at the Tip of a Dynamically Loaded Crack or Notch. Fort Belvoir, VA: Defense Technical Information Center, January 1993. http://dx.doi.org/10.21236/ada279791.

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8

Qamhia, Issam, Erol Tutumluer, and Han Wang. Aggregate Subgrade Improvements Using Quarry By-products: A Field Investigation. Illinois Center for Transportation, June 2021. http://dx.doi.org/10.36501/0197-9191/21-017.

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This report presents a case study for constructing aggregate subgrade improvement (ASI) layers using quarry by-product aggregates (QBA), a quarry mix of large primary crushed rocks (PCR) and sand-sized quarry fines. The construction took place at Larry Power Road in Bourbonnais Township in Kankakee County, Illinois, where the Illinois Department of Transportation placed two QBA mixes. The first mix (QBA_M1) consisted of 45% quarry by-products and 55% railroad ballast–sized 3×1 PCR. The second mix (QBA_M2) consisted of 31% and 69% quarry by-products and PCR, respectively. Two conventional ASI sections were also constructed conforming to Illinois Department of Transportation’s CS02 gradation. All sections consisted of a 9 in. (229 mm) QBA/PCR layer topped with a 3 in. (76 mm) dense-graded capping layer. Laboratory studies preceded the construction to recommend optimum quarry by-product content in the QBA materials and construction practice. The Illinois Center for Transportation research team monitored the quality and uniformity of the construction using nondestructive testing techniques such as dynamic cone penetrometer, lightweight deflectometer, and falling weight deflectometer. The segregation potential was monitored by visual inspection and imaging-based techniques. Short-term field evaluation of the constructed QBA layers, particularly QBA_M2 with a 31% quarry by-product content, showed no evidence of abnormal segregation and did not jeopardize the structural integrity of the QBA ASI layers, which had slightly lower but comparable strength and stiffness profiles to the conventional ASI sections. The use of QBA materials in ASI was field validated as a sustainable construction practice to provide stable pavement foundation layers.

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9

Zareian, Farzin, and Joel Lanning. Development of Testing Protocol for Cripple Wall Components (PEER-CEA Project). Pacific Earthquake Engineering Research Center, University of California, Berkeley, CA, November 2020. http://dx.doi.org/10.55461/olpv6741.

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This report is one of a series of reports documenting the methods and findings of a multi-year, multi-disciplinary project coordinated by the Pacific Earthquake Engineering Research Center (PEER) and funded by the California Earthquake Authority (CEA). The overall project is titled “Quantifying the Performance of Retrofit of Cripple Walls and Sill Anchorage in Single-Family Wood-Frame Buildings,” henceforth referred to as the “PEER–CEA Project.” The overall objective of the PEER–CEA project is to provide scientifically-based information (e.g., testing, analysis, and resulting loss models) that measure and assess the effectiveness of seismic retrofit to reduce the risk of damage and associated losses (repair costs) of wood-frame houses with cripple wall and sill anchorage deficiencies as well as retrofitted conditions that address those deficiencies. Tasks that support and inform the loss-modeling effort are: (1) collecting and summarizing existing information and results of previous research on the performance of wood-frame houses; (2) identifying construction features to characterize alternative variants of wood-frame houses; (3) characterizing earthquake hazard and ground motions at representative sites in California; (4) developing cyclic loading protocols and conducting laboratory tests of cripple wall panels, wood-frame wall subassemblies, and sill anchorages to measure and document their response (strength and stiffness) under cyclic loading; and (5) the computer modeling, simulations, and the development of loss models as informed by a workshop with claims adjustors. This report is a product of Working Group 3.2 and focuses on Loading Protocol Development for Component Testing. It presents the background, development process, and recommendations for a quasi-static loading protocol to be used for cyclic testing of cripple wall components of wood-frame structures. The recommended loading protocol was developed for component testing to support the development of experimentally informed analytical models for cripple wall components. These analytical models are utilized for the performance-based assessment of wood-frame structures in the context of the PEER–CEA Project. The recommended loading protocol was developed using nonlinear dynamic analysis of representative multi-degree-of-freedom (MDOF) systems subjected to sets of single-component ground motions that varied in location and hazard level. Cumulative damage of the cripple wall components of the MDOF systems was investigated. The result is a testing protocol that captures the loading history that a cripple wall may experience in various seismic regions in California.

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10

TENSILE BEHAVIOR OF T-STUB SUBJECTED TO STATIC AND DYNAMIC LOADS. The Hong Kong Institute of Steel Construction, August 2022. http://dx.doi.org/10.18057/icass2020.p.313.

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To study the tensile behavior of T-stubs with various design parameters under different loading scenarios, uniaxial static and dynamic tensile tests were carried out. The effects of flange thickness, bolt preload, bolt strength and loading conditions were discussed. The failure modes observed under different conditions were presented. Besides, the load-displacement response was analyzed in detail. The experimental results showed that the bolt preload only affected the initial stiffness of the specimens, and smaller flange thickness and lower bolt strength would result in unfavorable performance of T-stubs. Under dynamic loading scenarios, the test specimens showed greater resistance but limited deformation capacity compared to the static ones. Furthermore, it was observed that the ductility would be seriously reduced if brittle failure, such as bolt or weld fracture occurred which is recommended to be avoided in structural design.

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