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Mechanism of zonal disintegration in surrounding rock mass around deep rock engineering and its application

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Science china(Technological Sciences) 2011年第S1期54卷 221-227页

作者： ZHANG YongXing & ZHANG BoHu School of civil engineering,chongqing university,chongqing 400045,china School of civil engineering Chongqing University

The mechanical behaviors of deep rock mass are different from those of shallow rock *** cases of Jinping II Hydropower Station,the special phenomenon of zonal disintegration in the surrounding rock mass around the diversion tunnels,is *** the basis of fracture mechanics,a new strength criterion for deep rock mass is *** new nonlinear strength criterion that is relative to the rock mass rating classification can be applied to the study of the tensile failure of deep rock ***,zonal disintegration model is established,and the radius of fractured zone and none-fractured zone of deep surrounding rock mass around cylindrical tunnel are obtained,their exact positions and the evolution law of zonal disintegration of surrounding rock mass is *** validate the present model,comparison between calculation results and the experiment observation on facture and failure around underground openings is carried *** is found that the numerical simulation result is in good agreement with the experimental one on failure modes around the *** sensitivity analysis,the effects of stress condition,cohesion and the angle of internal friction on the phenomenon of zonal disintegration are ***,the present model is adopted in the analysis of the zonal disintegration in the surrounding rock mass around the diversion tunnels in Jinping II Hydropower ***,the magnitude and distributions of fractured zones are determined by numerical simulation.

关键词： deep rock mass zonal disintegration strength criteria of deep rock mass numerical simulation

A Numerical Stress-strain Response Model of All Grades of Concretes under Uniaxial Compression

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Journal of Wuhan university of Technology(Materials Science) 2006年第3期21卷 149-152页

作者：王勇威 college of Water Resource & Hydropower Sichuan UniversityChengdu 610065China

An important problem facing stress-strain response modeling of concrete is the complexity of the compressive strength grades. 21 groups of speeimens with different cubic compressive strength （56.3- 164.9 MPa ） hate beets numerically analyzed. Using only the compressive strength, a stress-strain response model of different concrete grade was established. The numerical simulation model not only qualitatively reproduces the relationship of uniaxial compressive strength, peak value stress and cubic compressive strength, but realizes the consistence of the ascending branch of stress-strain cunts with different strength grades by introducing the correction coefficient k. The results indicate k increases gradually from 0 to approximate 1 with the increase of the compressive strength, corresponding to the transition from the paracurve to straight line branch in stress-strain curves. When k is 0, the madel is identical to the Hognestad equation. A good agreement with the experiment data was obtained.

关键词： high-strength concrete stress-strain response mechanical property

Flow instability of buoyant-Marangoni convection in the LEC GaAs melt

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Science china(Technological Sciences) 2008年第4期51卷 397-406页

作者： CHEN ShuXian1 & LI MingWei2,3 1 Aviation engineering Institute, civil Aviation Flight university of china, Guanghan 618307, china 2 Institute of Power engineering of chongqing university, chongqing 400030, china 3 Research Center of Biological Function Information and Instruments of chongqing university by Sec-ond-Term National 985 Project, chongqing university, chongqing 400030, china Aviation engineering Institute Civil Aviation Flight University of China Guanghan 618307 China Institute of Power engineering of chongqing university Chongqing 400030 China

Flow transitions and instabilities have significant effects on the quality of the crystals. The flow and heat transfer in the LEC GaAs melt are numerically studied by a time-dependent and three-dimensional turbulent flow model. The effects of the change of the buoyancy and Marangoni force on the flow state are analyzed by changing the temperature difference between the crystal and the crucible walls. The results show that the flow will transform from axisymmetric steady flow to non-axisymmetric oscillatory flow when the temperature difference exceeds the critical value, and that the mechanism of the transition is attributed to the Marangoni instability. The critical temperature differences for the flow transitions corresponding to different melt depth H are numerically predicted. Several important characteristics of the non-axisymmetric buoyant-Marangoni convection are numerically observed and compared with that of the non-axisymmetric mixed convection coupled with crystal rotation.

关键词： flow transition flow instability buoyant-Marangoni convection mixed convection LEC GaAs melt

In-situ Characterization of Non-aqueous Nano-dispersion Systems by Freeze-etching TEM and Comparative Study with Laser Scattering Method

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Journal of Wuhan university of Technology(Materials Science) 2010年第3期25卷 432-436页

作者：欧忠文 Department of Architecture and civil engineering Logistics Engineering University

In-situ characterization of non-aqueous nano-dispersion systems（NANDS） by freeze-etching transmission electron microscope（FETEM） was *** improve just-for-once successive rate of specimen preparation and get good characterization results,an improving specimen preparation method of freezing etching was ***,distribution and morphology of NANDS were directly *** information of particle dispersion feature and particle density can also be *** of the FETEM characterization is *** with laser scattering method,which is liable to give positive error especially for small size particle anchoring disperser,FETEM characterization can give more accurate measurement of particle ***,FETEM can give dispersion feature of nanoparticle in non-aqueous medium.

关键词： non-aqueous nano-dispersion system dispersion state in-situ characterization freeze-etching laser scattering method

A geometrical and physical nonlinear finite element model for spatial thin-walled beams with arbitrary section

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Science china(Technological Sciences) 2010年第3期53卷 829-838页

作者： YANG QingShan 1 &WANG XiaoFeng 2 1 School of civil engineering,Beijing Jiaotong university,Beijing 100044,china 2 college of civil engineering,Tongji university,Shanghai 200092,china School of civil engineering Beijing Jiaotong University college of civil engineering Tongji University

Based on the theories of Bernoulli-Euler beams and Vlasov's thin-walled members,a new geometrical and physical nonlinear beam element model is developed by applying an interior node in the element and independent interpolations on bending angles and warp,in which factors such as traverse shear deformation,torsional shear deformation and their coupling,coupling of flexure and torsion,and second shear stress are all ***,geometrical nonlinear strain in total Lagarange(TL) and the corresponding stiffness matrix are *** plastic model is applied to physical nonlinearity to comply with the yield rule of Von Mises and incremental relationship of *** stiffness matrix is derived by numerical integration on the basis of the finite segment *** show that the developed model is feasible in analysis of thin-walled structures with high accuracy.

关键词： Spatial beams thin-walled structures geometrical and physical nonlinearity finite element arbitrary section

A new orthogonality relationship for orthotropic thin plate theory and its variational principle

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Science china(Physics,Mechanics & Astronomy) 2005年第3期48卷 371-380页

作者： LUO Jianhui 1 , LONG Yuqiu 2 & LIU Guangdong 1 1. college of civil engineering, Hunan university, Changsha 410082, china 2. Department of civil engineering, Tsinghua university, Beijing 100084, china college of civil engineering Hunan University Changsha China Department of civil engineering Tsinghua University Beijing China

The thought how dual vectors are constructed in a new orthogonality relationship for theory of elasticity is generalized into orthotropic thin plate bending problems by using the analogy theory between plane elasticity problems and plate bending problems. Dual differential equations are directly obtained by using a mixed variables method. A dual differential matrix to be derived possesses a peculiarity of which principal diagonal sub-matrixes are zero matrixes. Two independently and symmetrically orthogonality sub-relationships are discovered. By using the integral form for elastic bending theory of orthotropic thin plate the orthogonality relationship is demonstrated. By selecting felicitous dual vectors a new orthogonality relationship for theory of elasticity can be generalized into elastic bending theory of orthotropic thin plate. By using the integral form a variational principle which is relative to differential form and a whole function expression are proposed.

关键词： theory of elasticity, thin plate theory, dual vectors, orthogonality relationship, orthotropic, variational principle.

On Form Invariance,Lie Symmetry and Three Kinds of Conserved Quantities of Generalized Lagrange's Equations

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Communications in Theoretical Physics 2007年第7期48卷 37-42页

作者： ZHAO Shu-Hong LIANG Li-Fuoi School of civil engineering,Harbin engineering university,Harbin 150001,china2 engineering college,Northeast Agricultural university,Harbin 150030,china School of civil engineering Harbin Engineering University engineering college Northeast Agricultural University

In this paper,the form invariance and the Lie symmetry of Lagrange's equations for nonconservativesystem in generalized classical mechanics under the infinitesimal transformations of group are studied,and the Noether'sconserved quantity,the new form conserved quantity,and the Hojman's conserved quantity of system are derived ***,an example is given to illustrate the application of the result.

关键词： form invariance Lie symmetry conserved quantity generalized classical mechanics Lagrange’s equation

Integrated intelligent control analysis on semi-active structures by using magnetorheological dampers

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Science china(Technological Sciences) 2008年第12期51卷 2270-2284页

作者： XU ZhaoDong1 & GUO YingQing2 1civil engineering college, Southeast university, Nanjing 210096, china 2 Automation college, Southeast university, Nanjing 210096, china civil engineering college Southeast University Automation college Southeast University

The control strategy is very important for semiactive control or active control systems. An integrated intelligent control strategy for building structures incorpo rated with magnetorheological (MR) dampers subjected to earthquake excitation is proposed. In this strategy, the time-delay problem is solved by a neural network and the control currents of the MR dampers are determined quickly by a fuzzy controller. Through a numerical example of a three-storey structure with one MR damper installed in the first floor, the seismic responses of the uncontrolled, the intelligently controlled, the passiveon controlled, and the passive-off controlled structures under different earthquake excitations are analyzed. Based on the numerical results, it can be found that the time domain and the frequency domain responses are reduced effectively when the MR damper is added in the structure, and the integrated intelligent control strategy has a better earthquake mitigation effect.

关键词： magnetorheological damper semi-active control intelligent

On the general expressions of finite Hankel transform

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Science china(Physics,Mechanics & Astronomy) 2010年第11期53卷 2125-2130页

作者： JIANG Quan 1,2 & GAO CunFa 1 1 college of Aerospace engineering,Nanjing university of Aeronautics and Astronautics,Nanjing 210016,china 2 School of civil engineering,Nantong university,Nantong 226019,china Nanjing university of Aeronautics and Astronautics College of Aerospace Engineering Nanjing China (GRID:grid.64938.30) (ISNI:***) Nantong university School of Civil Engineering Nantong China (GRID:grid.260483.b) (ISNI:***) Nanjing university of Aeronautics and Astronautics College of Aerospace Engineering Nanjing China (GRID:grid.64938.30) (ISNI:***)

The general expressions of finite Hankel transform are naturally deduced with the help of the property of Bessel *** equations in this paper can degenerate into three kinds of boundaries since all the coefficients in the boundary conditions are taken into *** results can be adopted in solving physics problems involving the finite Hankel transform.

关键词： hankel transform bessel function finite integral