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Parametric Vibration Analysis of Submerged Floating Tunnel Tension Legs

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China Ocean engineering 2020年第1期34卷 131-136页

作者： SUN Sheng-nan SU Zhi-bin FENG Yun-fen XU Xian-yi school of architecture and civil engineering Liaocheng University

According to the characteristics of submerged floating tunnel anchored by tension legs,simplifying the tube as point mass and assuming that the tension leg is a nonlinear beam model hinged at both ends,the nonlinear vibration equation of the tension leg is *** equation is solved by the Galerkin method and Runge Kutta ***,numerical analysis of typical submerged floating tunnel tension leg is carried *** is shown that,the parametric vibration response of the submerged floating tunnel tension leg is related to the amplitude and frequency of the end *** considering axial resonance and transverse resonance,it is reasonable that higher order modes are abandoned and only the first three modes are *** axial resonance amplitude of the second or third order mode is equivalent to the first order mode axial resonance amplitude,which should not be ignored.

关键词： submerged floating tunnel tension leg parametric vibration numerical analysis

Seismic Response of Submerged Floating Tunnel Tether

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China Ocean engineering 2013年第1期27卷 43-50页

作者：苏志彬孙胜男 school of architecture and civil engineering Liaocheng University

A mathematical equation for vibration of submerged floating tunnel tether under the effects of earthquake and parametric excitation is presented. Multi-step Galerkin method is used to simplify this equation and the fourth-order Runge-Kuta integration method is used for numerical analysis. Finally, vibration response of submerged floating tunnel tether subjected to earthquake and parametric excitation is analyzed in a few numerical examples. The results show that the vibration response of tether varies with the seismic wave type; the steady maximum mid-span displacement of tether subjected to seismic wave keeps constant when parametric resonance takes place; the transient maximum mid-span displacement of tether is related to the peak value of input seismic wave acceleration.

关键词： submerged floating tunnel seismic response Runge-Kuta integration method tether parametric excitation

Aerodynamic stability of cable-stayed-suspension hybrid bridges

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Journal of Zhejiang University-Science A(Applied Physics & engineering) 2005年第8期6卷 869-874页

作者：张新军孙炳楠 school of civil engineering and architecture Zhejiang University of Technology school of civil engineering and architecture Zhejiang University

Three-dimensional nonlinear aerodynamic stability analysis was applied to study the aerodynamic stability of a cable-stayed-suspension (CSS) hybrid bridge with main span of 1400 meters, and the effects of some design parameters (such as the cable sag, length of suspension portion, cable plane arrangement, subsidiary piers in side spans, the deck form, etc.) on the aerodynamic stability of the bridge are analytically investigated. The key design parameters, which significantly influence the aerodynamic stability of CSS hybrid bridges, are pointed out, and based on the wind stability the favorable structural system of CSS hybrid bridges is discussed.

关键词： Cable-stayed-suspension (CSS) hybrid bridge Aerodynamic stability Parametric analysis

Influences of Reservoir Heterogeneity and Anisotropy on CO_2 Sequestration and Heat Extraction for CO_2-Based Enhanced Geothermal System

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Journal of Thermal Science 2019年第2期28卷 319-325页

作者： WANG Changlong HUANG Zhijia LU Yuehong TANG Gang LI Huan school of civil engineering and architecture Anhui University of Technology

Enhanced geothermal systems(EGS) have a great potential to extract geothermal energy and have attracted much interest. In this paper, based on a 3D thermal-hydrologic model considering CO_2 sequestration, the influences of reservoir heterogeneity and anisotropy on CO_2 sequestration and heat extraction in CO_2-based EGS are investigated. Different heterogeneous reservoirs and homogeneous reservoir are compared, and different ratios among reservoir permeability components are compared. The results show that greater reservoir heterogeneity enhances CO_2 sequestration and restrains heat extraction. Higher ratio between horizontal(x and y directions) and vertical permeability components enhances CO_2 sequestration and heat extraction, and vertical permeability component has a little effect. With the increasing ratio between x-directional(perpendicular to the line of the injection well and the production well) and y-directional(perpendicular to x direction) reservoir permeability components(i.e. kx:ky), both CO_2 sequestration amount and steady-state heat extraction rate first increase and then decrease, and thermal breakthrough time increases, showing that there exists an optimum kx:ky, which is about 1:1. The results of this paper indicate that reservoir heterogeneity and anisotropy have important influences on CO_2 sequestration and heat extraction.

关键词： enhanced geothermal system CO2 sequestration heat extraction reservoir heterogeneity reservoir anisotropy

An eigen theory of static electromagnetic field for anisotropic media

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Applied Mathematics and Mechanics(English Edition) 2009年第5期30卷 643-652页

作者：郭少华 school of civil engineering and architecture Zhejiang University of Science and Technology school of civil engineering and architecture Central South University

Static electromagnetic fields are studied based on standard spaces of the physical presentation, and the modal equations of static electromagnetic fields for anisotropic media are derived. By introducing a new set of first-order potential functions, several novel theoretical results are obtained. It is found that, for isotropic media, electric or magnetic potentials are scalar; while for anisotropic media, they are vectors. Magnitude and direction of the vector potentials are related to the anisotropic subspaces. Based on these results, we discuss the laws of static electromagnetic fields for anisotropic media.

关键词： anisotropic media static electromagnetic field standard spaces modal equation

SYMPLECTIC ANALYSIS FOR WAVE PROPAGATION OF HIERARCHICAL HONEYCOMB STRUCTURES

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Acta Mechanica Solida Sinica 2015年第3期28卷 294-304页

作者： Kai Zhang Zichen Deng Xiaojian Xu Xiuhui Hou Junmiao Meng school of Mechanics Civil Engineering and Architecture Northwestern Polytechnical University school of civil engineering Chang'an University

Wave propagation in two-dimensional hierarchical honeycomb structures with two- order hierarchy is investigated by using the symplectic algorithm. By applying the variational prin- ciple to the dual variables, the wave propagation problem is transformed into a two-dimensional symplectie eigenvalue problem. The band gaps and spatial filtering phenomena are examined to find the stop bands and directional stop bands. Special attention is directed to the effects of the relative density and the length ratio on the band gaps and phase constant surfaces. This work provides new opportunities for designing hierarchical honeycomb structures in sound insulation applications.

关键词： hierarchical honeycomb structures wave propagation band gap phase constant surface symplectic analysis

Directional interpolation infinite element for dynamic problems in saturated porous media

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Earthquake engineering and engineering Vibration 2020年第3期19卷 625-635页

作者： Xiong Hao Chen Qingsheng Zhu Bingjian school of civil engineering and architecture Taizhou UniversityTaizhou 318000China school of civil Architecture and Environmental EngineeringHubei University of TechnologyWuhan 430068China

In this study,a directional interpolation infinite element suited to a saturated porous medium is presented to account for dynamic problems with semi-infinite or infinite *** employing the Galerkin method,the element property matrixes for a two-dimensional space are *** the governing differential equations for wave propagation in the saturated porous media,the analytical solutions for one-dimensional wave propagation are derived in *** the shape functions for the infinite element based on the analytical solutions are formulated and the dynamic stiffness matrix is presented in analytical form is *** a result,a fully coupled 2 D infinite element for the analysis of dynamic problems in unbounded saturated porous media is *** effectiveness and accuracy of the proposed element is well demonstrated by a comparison of the numerical results with known analytical solutions for 1 D and 2 D wave propagation *** results highlight that the proposed directional interpolation infinite element is useful and effective for addressing the dynamic problems with semi-infinite or infinite domain,with consideration of both compression and shear waves.

关键词： element saturated dynamic

Parametric Vibration of Submerged Floating Tunnel Tether Under Random Excitation

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China Ocean engineering 2011年第2期25卷 349-356页

作者：孙胜男苏志彬 school of architecture and civil engineering Liaocheng University

For the study of the parametric vibration response of submerged floating tunnel tether under random excitation, a nonlinear random parametric vibration equation of coupled tether and tube of submerged floating tunnel is set up. Subsequently, vibration response of tether in the tether-tube system is analyzed by Monte Carlo method. It may be concluded that when the tube is subjected to zero-mean Gaussian white noise random excitation, the displacement and velocity root mean square responses of tether reach the peak if the circular frequency of tube doubles that of tether; the displacement and velocity root mean square responses of tether increase as the random excitation root mean square increases; owing to the damping force of water, the displacement and velocity root mean square responses of tether decrease rapidly compared with tether in air; increasing the damping of the tether or tube reduces the displacement and velocity root mean square responses of tether; the large-amplitude vibration of tether may be avoided by locating dampers on the tether or tube.

关键词： ocean engineering submerged floating tunnel tether parametric vibration random excitation

Equivalent model of close-packed film cooling holes in nickel-based single crystal cooled blade based on crystallographic theory

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Chinese Journal of Aeronautics 2019年第4期32卷 839-850页

作者： Yamin ZHANG Zhixun WEN Haiqing PEI Zhufeng YUE school of Mechanics Civil Engineering and ArchitectureNorthwestern Polytechnical University

The mechanical properties of nickel-based single crystal thin-walled plate with close-packed film cooling holes were studied based on the equivalent solid material concept. The effective plastic parameters inversion method based on crystallographic theory were proposed. A simplification method for close-packed film cooling hole plates with square and triangular penetration patterns was presented. A large number of finite element analysis results covering different ligament efficiencies and penetration patterns were provided to verify the feasibility of the plastic equivalent principle and simplification method. The results show that the stress–strain curve and resolved shear stresses of simplification models are in consistence with the plate models with close-packed film cooling holes. The equivalent errors of yield strength are all within the error band and the values of equivalent errors are all less than 10%. In addition, the equivalent errors of the positions where maximum resolved shear stress occurs are all less than 15°, indicating the accuracy of plastic equivalent model and simplification method.

关键词： Close-packed film cooling holes Crystallographic theory Equivalent Simplification Single crystal