Characteristics of Deformation and Strength of Concrete in Plane Strain State     

Song Yupu Zhao Guofan Professor 《中国海洋工程》1993,(1)

- The characteristics of deformation and strength of concrete under the plane strain condition are studied experimentally with the triaxial apparatus designed by the authors and are compared with those under the plane stress condition. A formula of stress transformation between plane stress and plane strain conditions is proposed for the elasto-plastic state, and it provides a theoretical basis for simplifying nonlinear analysis and fully using the strength of concrete.  相似文献   

Moon mass approximation in algebraic form analogous to activity sphere formula     

Professor of Aerospace Engineering Irving Michelson 《Pure and Applied Geophysics》1966,63(1):105-108

Summary The concept of comet orbit activity sphere as introduced byD'Alembert and developed byLaplace is modified and applied to the Sun-Earth-Moon system, leading to a new approximate relationship between astronomical constants usually regarded as independent quantities. When Sun-Earth mass ratio, the astronomic unit, and Earth-Moon separation distance are taken as known, an elementary algebraic formula gives the Earth-Moon mass ratio in terms of these. Despite the inherently imprecise character of this type of calculation, surprisingly close numerical agreement with independently determined values is obtained. The great simplicity and directness of the result contrast with ardous orthodox inference procedures for the lunar mass, suggesting that newer methods of general dynamic analysis are required in the study of asymptotic states of the three-body problem.  相似文献   

Numerical Simulation and Physical Simulation of Sea Wave Groups     

Yu Yuxiu  Gui Manhai Professor  Dept. of Civil Eng. Dalian University of Technology 《中国海洋工程》1996,(3)

- Based on field wave data, an empirical formula of wave envelope spectrum is given in this paper. Then the methods of both numerical and physical simulation of sea wave groups with the given spectrum and groupiness parameters are suggested.  相似文献   

Postbuckling of Imperfect Stiffened Cylindrical Shells Under Combined External Liquid Pressure and Axial Compression     

Shen Huishen Professor 《中国海洋工程》1996,(4)

- posthuckling analysis is presented for the stilTened cylindrical shell of finite length subjected to combined loading of external liquid pressure and axial compression. The formulations are based on a boundary layer theory of shell buckling, which includes the effects of nonlinear prebuckling deformations, nonlinear large deflections in the postbuckling range and initial geometrical imperfections of the shell. The "smeared stifl'cner" approach is adopted for the stiffencrs. In the analysis a singular perturbation technique is used (o determine the interactive buckling loads and the postbuckling paths. Numerical examples cover the performance of perfect and imperfect, stringer and ring stiffened cylindrical shells. Typical results arc presented in the dimcnsionless graphical form.  相似文献   

Analysis of Dynamic Stability of Ocean Gravity Structure Foundations     

He Guangna  Cao Yalin Professor  Dalian University of Technology  Dalian . Former Postgruate Student  Dalian University of Technology  Dalian 《中国海洋工程》1995,(2)

Based on unified equivalent harmonic loading on seabed foundation and energy approach suggested by the authors, the development of dynamic pore water pressure and stability of soil foundation for the vibration of ocean gravity structures excited by random wave loading are analysed. It may be seen that the present method for the study of dynamic problems of ocean gravity structure soil foundations is more reasonable and convenient.  相似文献   

Statistical Distributions of Wavelengths     

Yu Dingyong Xu Delun Ph. D. Student  Engineering College  Ocean University of Qingdao  Qingdao Professor  Physical Oceanography Laboratory  Ocean University of Qingdao  Qingdao 《中国海洋工程》1997,(3)

The statistical distribution of wavelength is directly derived from a two-dimensional andspatially homogeneous Gaussian wave field.The present result differs from both the result of Rayleigh dis-tribution and Sun's result(1988b)which is transformed through the period distribution derived from atwo-dimensional and stationary Gaussian wave field.A laboratory experiment shows that the present re-sult is more consistent with the observations in the wave tank than the others.  相似文献   

Experimental Study of Hydrodynamic Loading on Submarine Composite Pipelines under the Action of Waves and Current     

Ma Liang  Wang Jinying Xing Zhizhuang Sun Shaoshu Professor  Dalian University  Dalian Senior Engineer  China Offshore Oil Engineering Co. 《中国海洋工程》1994,(2)

- This article is aimed at the experimental study of the hydrodynamic loading induced by waves and current acting on the JZ 20-2 submarine composite pipelines. The corresponding hydrodynamic coefficients obtained in this experimental study can be applied to engineering projects.  相似文献   

A numerical method for the solution of a line source under a free surface     

Iskender Sahin  Assistant Professor  Allen H. Magnuson  Asssciate Professor 《Ocean Engineering》1984,11(5):451-461

A modified source-and-dipole type singularity panel method is proposed to calculate the flow properties for an oscillating arbitrary body in the presence of a free surface. The technique is based on Green's identity whereby the boundary value problem is expressed as a boundary integral equation which is solved numerically. The free-space Green function is used in the integral equation. To demonstrate the feasibility of the method, the problem of a pulsating submerged line source under a free surface is treated and results are compared with the exact solution.An excellent agreement with the theory is obtained for panel density of about ten panels per wavelength and paneled water surface length of two wavelengths with very low computing times, indicating the feasibility of the method for unsteady water wave problems.  相似文献   

Linearization methods and the influence of current on the nonlinear hydrodynamic drag force     

Ove T. Gudmestad  Senior Engineer  Jerome J. Connor  Professor of Civil Engineering 《Applied Ocean Research》1983,5(4):184-194

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Determination of Partial Factors of Breast Wall on Top of Sloping Breakwater     

Lu Jianghua Xie Shileng Engineer  Planning  Design Institute for Water Transportation  Ministry of Communications  Beijing Professor  Senior Engineer  First Design Institute of Navigation Engineering  Ministry of Communications  Tianjin 《中国海洋工程》1996,(4)

- By applying the theory of structural reliability, reliability analyses for the stability of a breast wall on the top of a sloping breakwater are carried out. Based on the analyses, the method for determining partial action / load factors and partial resistance factors of breast walls is expounded, and the design expressions with partial factors are given. The values of partial action / load factors and partial resistance factors are recommended preliminarily according to the computation for breast walls with typical cross-sections.  相似文献