The Experts below are selected from a list of 120726 Experts worldwide ranked by ideXlab platform
Yang Shi-ruo - One of the best experts on this subject based on the ideXlab platform.
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Coupling vibration analysis of vehicle-bridge by mode method
Journal of Shenzhen University Science and Engineering, 2011Co-Authors: Yang Shi-ruoAbstract:The free vibration mode of the truss girder bridge and normal coordinates are taken as displacement functions of the bridge vibration.By coupling the vehicle and the truss girder bridge as one composite system,the Total Potential Energy of the vehicle and the truss girder bridge under normal coordinates are calculated.Based on the principle of the Total Potential Energy with stationary value in elastic system and the set-in-right-position rule for forming structural matrices,the vibration equations of vehicle-bridge are established in time-varying system.The calculation results are compared with the ones by non-mode method.The minimum error of the results by the two methods is 0.16%.The mode method could reduce the degrees of freedom of the vehicle-bridge system,thus it reduces the computing time considerably.
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Vehicle-Bridge Vibration Analysis of Arch-Truss Composite Bridge Using Mode Method
Noise and Vibration Control, 2011Co-Authors: Yang Shi-ruoAbstract:The free vibration characteristics of the arch-truss composite bridge are calculated.Then,taking the free vibration modes of the bridge and normal coordinates as displacement functions of the bridge vibration,and the vehicle and the bridge as a system,the Total Potential Energy of the vehicle and bridge structure under normal coordinates is calculated. Based on the principle of the stationary Total Potential Energy in elastic system and the coding method for forming structural matrices,the vibration equations of vehicle-bridge time-varying system are established and solved.The former 20,40,60 and 90 order vibration modes of the bridge structure are calculated.The vehicle-bridge vibration responses of the truss-arch composite system are calculated when goods trains pass through the bridge at the speed of 80 km/h.The results are compared with those by using non-mode method.The minimum error is 0.17%only.
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Analysis of vehicle-bridge vibration of continuous truss girder bridge by mode method
Journal of Central South University of Forestry & Technology, 2010Co-Authors: Yang Shi-ruoAbstract:The free vibration mode of the bridge and normal coordinates were taken as displacement functions of the bridge vibration.By coupling the vehicle and the bridge as one composite system,the Total Potential Energy of the vehicle and bridge structure under normal coordinates were calculated.Based on the principle of the Total Potential Energy with stationary value in elastic system and the "set-in-right-position" rule for forming structural matrices,the vibration equations of vehicle-bridge time varying system were established and solved.This method could reduce the degrees of freedom of the vehicle-bridge system and required computing time considerably.The vehicle-bridge vibration responses of a continuous truss girder bridge were calculated,furthermore,the amplitude in lower chord of the No.41 Bridge of the system was calculated using this method.The calculation results are close to the observed values,which prove the reliability of the method.
Zhaobin Su - One of the best experts on this subject based on the ideXlab platform.
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a lattice dynamical treatment for the Total Potential Energy of single walled carbon nanotubes and its applications relaxed equilibrium structure elastic properties and vibrational modes of ultra narrow tubes
Journal of Physics: Condensed Matter, 2008Co-Authors: Jinwu Jiang, Hui Tang, Bingshen Wang, Zhaobin SuAbstract:In this paper, we propose a lattice dynamic treatment for the Total Potential Energy of single-walled carbon nanotubes (SWCNTs) which is, apart from a parameter for the nonlinear effects, extracted from the vibrational Energy of the planar graphene sheet. The energetics, elasticity and lattice dynamics are treated in terms of the same set of force constants, independently of the tube structures. Based upon this proposal, we have investigated systematically the relaxed lattice configuration for narrow SWCNTs, the strain Energy, the Young's modulus and Poisson ratio, and the lattice vibrational properties with respect to the relaxed equilibrium tubule structure. Our calculated results for various physical quantities are nicely in consistency with existing experimental measurements. In particular, we verified that the relaxation effect makes the bond length longer and the frequencies of various optical vibrational modes softer. Our calculation provides evidence that the Young's modulus of an armchair tube exceeds that of the planar graphene sheet, and that the large diameter limits of the Young's modulus and Poisson ratio are in agreement with the experimental values of graphite; the calculated radial breathing modes for ultra-narrow tubes with diameters ranging between 2 and 5 A coincide with the experimental results and the existing ab initio calculations with satisfaction. For narrow tubes with a diameter of 20 A, the calculated frequencies of optical modes in the tubule's tangential plane, as well as those of radial breathing modes, are also in good agreement with the experimental measurements. In addition, our calculation shows that various physical quantities of relaxed SWCNTs can actually be expanded in terms of the chiral angle defined for the corresponding ideal SWCNTs.
S.s. Dey - One of the best experts on this subject based on the ideXlab platform.
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Integrated analysis of curved bridge superstructures by variational finite difference method
Computers & Structures, 1991Co-Authors: A.k. Verma, S.s. DeyAbstract:Abstract Static analysis of bridge superstructures which are curved in plan, having radial as well as circumferential beams, and continuous over axially flexible column supports is proposed using a variational based finite difference Energy method. The Total Potential Energy of the system composed of different components of the bridge decks is discretized in terms of pivot displacements with the help of finite difference operators with constant order of truncation error. The principle of minimum Total Potential Energy is applied to obtain the force-displacement relationship which was solved for pivot displacements. In order to estimate the accuracy and reliability of the present formulation several problems of curved plates with increasing order of complexity are solved. The results are compared with the existing solutions.
Farnaz Sadeghpour - One of the best experts on this subject based on the ideXlab platform.
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dynamic site layout planning through minimization of Total Potential Energy
Automation in Construction, 2013Co-Authors: Mohsen Andayesh, Farnaz SadeghpourAbstract:Dynamic site layout planning is the task of determining the overall optimum location of objects such as temporary facilities, storage areas, and workshops on the construction site. This paper presents an innovative dynamic model that is able to generate layouts that are optimized over the duration of the project. The model applies Energy principles governing a physical system to search for the optimum location of objects. In this model, objects with more impact on the layout are able to obtain and reserve their optimum locations even if they arrive to the construction site in later stages. The model allocates space to objects only for the duration they are required on the site, and accordingly, it enables a realistic representation of space availability on the site and allows the reuse of space over the time. A numerical example is presented to demonstrate the capability of the developed model.
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dynamic site layout planning using mtpe principle from physics
28th International Symposium on Automation and Robotics in Construction, 2011Co-Authors: Mohsen Andayesh, Farnaz SadeghpourAbstract:Site layout planning is the task of determining optimum location for construction facilities on the site in order to increase productivity and safety of the project. Most of the existing studies assume all facilities are required for the entire duration of the project which is not a realistic scenario. More advanced studies have proposed dynamic models to reflect the changes in the project requirements over the course of time. They generate optimum layouts for a set of consecutive time intervals. However, combining individually optimized layouts does not necessarily guarantee globally optimum locations for facilities. In addition, forcing facilities to fit in a set of predetermined time intervals can lead to waste of space and inefficient layouts. This research adopts the Minimum Total Potential Energy (MTPE) principle from physics to develop a dynamic planning model which generates layouts that are globally optimized. It assumes construction site to be a physical system in which construction facilities represent particles and the internal forces among particles reflect the closeness constraints between facilities. The Total Potential Energy of the system represents the fitness of the layout for the defined objective function. Based on MTPE principle, the internal forces cause particle to search for a location with lower Potential Energy until the system reaches equilibrium. The final state of particles represents the minimum Total Potential Energy of the system, which reflects the fittest arrangement for the facilities on the site. A computational example is analyzed to investigate the accuracy of the proposed model and demonstrate its capabilities.
Bingshen Wang - One of the best experts on this subject based on the ideXlab platform.
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a lattice dynamical treatment for the Total Potential Energy of single walled carbon nanotubes and its applications relaxed equilibrium structure elastic properties and vibrational modes of ultra narrow tubes
Journal of Physics: Condensed Matter, 2008Co-Authors: Jinwu Jiang, Hui Tang, Bingshen Wang, Zhaobin SuAbstract:In this paper, we propose a lattice dynamic treatment for the Total Potential Energy of single-walled carbon nanotubes (SWCNTs) which is, apart from a parameter for the nonlinear effects, extracted from the vibrational Energy of the planar graphene sheet. The energetics, elasticity and lattice dynamics are treated in terms of the same set of force constants, independently of the tube structures. Based upon this proposal, we have investigated systematically the relaxed lattice configuration for narrow SWCNTs, the strain Energy, the Young's modulus and Poisson ratio, and the lattice vibrational properties with respect to the relaxed equilibrium tubule structure. Our calculated results for various physical quantities are nicely in consistency with existing experimental measurements. In particular, we verified that the relaxation effect makes the bond length longer and the frequencies of various optical vibrational modes softer. Our calculation provides evidence that the Young's modulus of an armchair tube exceeds that of the planar graphene sheet, and that the large diameter limits of the Young's modulus and Poisson ratio are in agreement with the experimental values of graphite; the calculated radial breathing modes for ultra-narrow tubes with diameters ranging between 2 and 5 A coincide with the experimental results and the existing ab initio calculations with satisfaction. For narrow tubes with a diameter of 20 A, the calculated frequencies of optical modes in the tubule's tangential plane, as well as those of radial breathing modes, are also in good agreement with the experimental measurements. In addition, our calculation shows that various physical quantities of relaxed SWCNTs can actually be expanded in terms of the chiral angle defined for the corresponding ideal SWCNTs.
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a lattice dynamical treatment for the Total Potential Energy of single walled carbon nanotubes and its applications relaxed equilibrium structure elastic properties and vibrational modes of ultra narrow tubes
arXiv: Materials Science, 2006Co-Authors: Jinwu Jiang, Hui Tang, Bingshen WangAbstract:In this paper, we proposed a lattice dynamic treatment for the Total Potential Energy for single-walled carbon nanotubes (SWCNT's) which is, apart from a parameter for the non-linear effects, extracted from the vibrational Energy of the planar graphene sheet. Based upon the proposal, we investigated systematically the relaxed lattice configuration for narrow SWCNT's, the strain Energy, the Young's modulus and Poisson ratio, and the lattice vibrational properties respected to the relaxed equilibrium tubule structure. Our calculated results for various physical quantities are nicely in consistency with existing experimental measurements. Particularly, we verified that the relaxation effect brings the bond length longer and the frequencies of various optical vibrational modes softer; Our calculation provides the evidence that the Young's modulus of armchair tube exceeds that of the planar graphene sheet, and the large diameter limits of the Young's modulus and Poisson ratio are in agreement with the experimental values of the graphite; The calculated radial breathing modes for the ultra narrow tubes with diameter range between 0.2 - 0.5 nm coincide the experimental results and the existing {\it ab initio} calculations with satisfaction; For narrow tubes of diameter 2 nm, the calculated frequencies of optical modes in tubule tangential plane as well as those of radial breathing modes are also in good agreement with the experimental measurement. In addition, our calculation shows that various physical quantities of relaxed SWCNT's can actually be expanded in terms of the chiral angle defined for the correspondent ideal SWCNT's.
