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11.
A new three-dimensional transducer system is introduced in this paper, which enables the measurement of six internal components
of strain tensor in concrete members. Laboratory tests and strain analyses were carried out to evaluate this tranducer system.
The results show that the system is effective in measuring internal strains of concrete members. It was then embedded in a
reinforced concrete bridge deck in Macomb County, Michigan. Field tests were conducted to measure the strains in the deck
under truck wheel load. The results were used to understand the deck's strain and stress behavior under truck wheel load. 相似文献
12.
Benchmark solution of angle-ply piezoelectric-laminated cylindrical panels in cylindrical bending with weak interfaces 总被引:3,自引:0,他引:3
The bending problem of a simply supported, angle-ply piezoelectric-laminated cylindrical panel in cylindrical bending with weak interfaces is considered. A general spring-layer model is adopted to describe the weakness of imperfect interfaces. An exact analysis is performed via the state-space approach. A new system of physical variables is introduced and a variable substitution technique is employed to derive a state equation with constant coefficients. Numerical results are given to show the effect of weak interfaces.The work was supported by the National Natural Science Foundation of China (No. 10372088) and by the Korea Institute of Science and Technology Evaluation and Planning. 相似文献
13.
Paulo B. Gonçalves Frederico M. A. Silva Zenón J. G. N. Del Prado 《Nonlinear dynamics》2007,50(1-2):121-145
In the present study, the large-amplitude vibrations and stability of a perfect circular cylindrical shell subjected to axial
harmonic excitation in the neighborhood of the lowest natural frequencies are investigated. Donnell's shallow shell theory
is used and the shell spatial discretization is obtained by the Ritz method. An efficient low-dimensional model presented
in previous publications is used to discretize the continuous system. The main purpose of this work is to discuss the use
of basins of attraction as a measure of the reliability and safety of the structure. First, the nonlinear behavior of the
conservative system is discussed and the basin structure and volume is understood from the topologic structure of the total
energy and its evolution as a function of the system parameters. Then, the behavior of the forced oscillations of the harmonically
excited shell is analyzed. First the stability boundaries in force control space are obtained and the bifurcation events connected
with these boundaries are identified. Based on the bifurcation diagrams, the probability of parametric instability and escape
are analyzed through the evolution and erosion of basin boundaries within a prescribed control volume defined by the manifolds.
Usually, basin boundaries become fractal. This together with the presence of catastrophic subcritical bifurcations makes the
shell very sensitive to initial conditions, uncertainties in system parameters, and initial imperfections. Results show that
the analysis of the evolution of safe basins and the derivation of appropriate measures of their robustness is an essential
step in the derivation of safe design procedures for multiwell systems. 相似文献
14.
Based on the extended Langmuir's method, accurate analytic expressions for the electrical properties of cylindrical colloidal particle in a solution of symmetric electrolyte are derived from the nonlinear cylindrical Poisson-Boltzmann equation. Comparison is made with previous literature results. The present formulae have good agreement with literature values and are quite simple for practical use. 相似文献
15.
In this article, accurate analytic expressions of the surface charge density/surface potential and adsorption excesses for cylindrical reverse micelle in a solution of symmetric electrolyte are derived from the nonlinear cylindrical Poisson–Boltzmann equation. These expressions are in good agreement with numerical values and Van Aken's results for cylindrical reverse micelle with high surface potentials and large κa. 相似文献
16.
In the present work, the use of cylindrical turbulators in a double pipe heat exchanger has been investigated. Cylindrical fin type of turbulators has been placed circumferentially separated by 90° on the outer side of an inner pipe at a regular pitch. Experimental studies were undertaken for different air flow rates in a turbulent regime whose Reynolds number range between 2500 and 10000. Heat transfer characteristics like Nu and friction factor have been experimentally determined. Parametric studies were conducted by changing the pitch and also the orientation of the turbulators. Nu and friction factor were found to increase as the pitch is reduced. A model with alternatively changed orientation outperformed others by exhibiting highest Nu and reduced friction factor. 相似文献
17.
《Physics letters. A》2019,383(19):2272-2276
Magnetic field design is important in cylindrical Hall thrusters and using permanent magnets to generate magnetic field is very promising in the future. In two typical permanent magnet configurations (i.e., ring and cylindrical configurations) of cylindrical Hall thrusters, discharge characteristics are compared in this paper through the experiments and simulations. The study shows that the cylindrical configuration can bring about higher thruster performance in the same working condition. The reason is that the potential drop of the cylindrical configuration is mainly concentrated in the channel, which is beneficial for the electrons to obtain energy to promote the ionization of the propellant. However, the voltage regulation range of the cylindrical configuration is lower because the anode is more easily overheated. 相似文献
18.
Luis Escauriaza 《偏微分方程通讯》2013,38(5-6):821-845
It is shown that any elloptic or parabolic operator in nondivergence form with measurable coefficients has a global fundamental solution verifying certain pointwise bounds. 相似文献
19.
Piezoelectric cat-eye modulating retro-reflector (MRR) is the core component of an acousto-optic retro-identification system. The influence of the optical parameters (link distance l, lens focal length f and the detector diameter r) to the cat-eye effect was analyzed theoretically and experimentally. A piezoelectric cat-eye retro-identification (PCERI) system was built, and an information transmission ratio of 2 kHz was achieved which can satisfy an access control system. 相似文献
20.
The aim of this paper is to develop a reduction method to determine the modal characteristics of viscoelastic sandwich structures. The method is based on the high order Newton algorithm and reduction techniques. Numerical tests have been performed in the case of sandwich beams and cylindrical shells. The comparison of the results obtained by the reduction method with those given by direct simulation shows both a good agreement and a significant reduction in computational cost. 相似文献