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51.
Lian Gan Ni Kan Hu Kai Guo Dawei . Professor Senior Engineer Marine Design & Research Institute of China Shanghai
. Senior Engineer Marine Design & REsearch Institute of China Shanghai
. Engineer Marine Design & Research Institute of China Shanghai 《中国海洋工程》1992,(4)
This paper describes the study of a single-column structure used as well-head platform. In order to check the reliability of computation theory and programme, model tests have been carried out. The paper introduces the conclusion of tests and the dynamic properties of single-column platform are obtained. 相似文献
52.
Chen Tieyun Zhu Zhenghong
Professor Dept. of Naval Architecture Ocean Engineering Shanghai Jiao Tong University Shanghai Lecturer 《中国海洋工程》1991,(1)
The plastic node method is reformulated by the variational principle and is applied to elasto-plastic finite element analysis of tubular joints, eventually including the effect of internal and external gussets, stiffener rings, etc., if necessary. Four different joints are studied here in detail for the elasto-plastic behavior, the strain at the hot spot, the strain concentration factor around the intersection line, and the propagation of the plastic region with loading up to collapse in order to determine the ultimate strength, safety factor, and development of the plastic field. The present results are in good agreement with the experimental results. 相似文献
53.
Wave-Current Forces on Slender Circular Cylinders 总被引:3,自引:0,他引:3
Li Yucheng Wang Fenglong Kang Haigui Professor Dalian University of Technology Dalian Senior Engineer Dalian University of Technology Dalian Lecturer Dalian University of Technology Dalian 《中国海洋工程》1991,(3)
- A series model tests of wave forces by both regular and irregular waves combined with currents on single piles and bipiles in tandem and parallel arrays have been carried out. Based on Morison Equation, linear wave theory and linear wave spectrum theory as well, the characteristics of inline, lift and resultant forces on cylinders have been analyzed respectively. The drag, inertia and lift coefficients CD, CM and CL f皉 single piles related to KC number and the grouping effect coefficients of inline, lift and resultant forces on bipiles in tandem and parallel arrays related to KC number are given in this paper. 相似文献
54.
Yu Yuxiu Liu Shuxue Li Li Professor Dept. of Civil Engineering Dalian University of Technology Dalian
Research Assistant Dept. of Civil Engineering Dalian University of Technology Dalian 《中国海洋工程》1991,(3)
Multi-directional irregular waves are simulated on the basis of the given directional spectrum using a double summation model, a single direction per frequency model and a single summation model. Their results are compared. It is shown that the single direction per frequency model proposed in this paper can generate a realistic wave field. The effects of the model parameters on the simulated results are also studied in this paper and corresponding suggestions are given. 相似文献
55.
Yu Kuang-ming Zhang Jiachang Zhou Jiabao Professor Senior Engineer The River Harbour Department Nanjing Hydraulic Research Institute Nanjing Senior Engineer The River Harbour Department Nanjing Hydraulic Research Institute Nanjing 《中国海洋工程》1991,(4)
An empirical formula for estimating the overtopping discharge of wind-waves on a smooth-impermeable-simple slope dyke is derived through model tests in this paper, it can be adopted by related design departments in the determination of the crest elevation of the dyke. 相似文献
56.
A Note on Soil Structure Resistance of Natural Marine Deposits 总被引:1,自引:1,他引:1
It has been well documented that natural normally-consolidated marine soils are generally subjected to the effects of soil structure. The interpretation of the resistance of soil structure is an important issue in the theory study and engineering practice of ocean engineering and geotechnical engineering. It is traditionally considered that the resistance of soil structure gradually disappears with increasing stress level when the applied stress is beyond the consolidation yield stress. In this study, however, it is found that this traditional interpretation of the resistance of soil structure can not explain the strength behavior of natural marine deposits with a normally-consolidated stress history A new interpretation of the resistance of soil structure is proposed based on the strength behavior. In the preyield state, the undrained strength of natural marine deposits is composed of two components: one developed by the applied stress and the other developed by the resistance of soil structure. When the applied stress is beyond the consolidation yield stress, the strength behavior is independent of the resistance of soil structure. 相似文献
57.
The effect of the cone spacing of a conieal structure on the ice force is studied by model experiments. The ice force reduction coefficient presented in this paper expresses the relationship between the ice force and the arrangement of cones. The experiments prove that the mode of the ice failure before the boundary of upward-downward bending cone (UDBC) is crushing. A conclusion can also be drawn from the experiments that the ice force on the boundary of UDBC is by far less than that on a vertical pile with the same diameter. Moreover, the ice force frequencies on upright and inve-rted cones are obtained under the field condition of the platform JZ20-2, respectively. The results show that the alterna-tion of the ice force on UDBC can hardly induce resonance of platform JZ20-2. 相似文献
58.
Based on Hong‘s theory, previous random models, and a generalized expression suitable for FIT calculation, the interaction between irregular waves and vertical walls is numerically simulated. The results of simulation demonstrate that the wave energy changes with the incidence angle and the distance from the wall. Particularly, the Mach effect and the combined wave spectrum characteristics are analyzed in detail, which are significant in both theory and practice. 相似文献
59.
Analysis of Dynamic Characteristics of Submarine Free Spanning Pipelines by Complex Damping Method 总被引:2,自引:0,他引:2
Considering the effect of the internal flowing fluid and the external marine environmental condition, the differential equation for the vortex-induced vibration (V1V) of the free spanning pipeline is derived and is discretized by the Hermit interpolation function. The free vibration equation with the damping term is solved by the complex damping method for the natural frequency, and then the effect of fluid damping on the natural frequency of the free spanning pipeline is analyzed.The results show that fluid damping has a significant influence on the damped natural frequency of the free spanning pipeline in the lock-in state, while it has little influence when the pipeline is out of the lock-in state. In the meantime,the change of the free span length has the same effect on the damped natural frequency and the undamped natural frequency. 相似文献
60.
An optimization mathematical model of the pile forces for piled breasting dolphins in the open sea under various loading conditions is presented. The optimum layout with the well distributed pile forces and the least number of piles is achieved by the multiplier penalty function method. Several engineering cases have been calculated and compared with the result of the conventional design method. It is shown that the number of piles can be reduced at least by 10%—20% and the piles‘ bearing state is improved greatly. 相似文献