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Frontiers of Structural and Civil Engineering 2019年第5期13卷 1200-1213页

作者： Shaochun WANG Xi JIANG Yun BAI Department of Geotechnical Engineering College of Civil EngineeringTongji UniversityShanghai 200092China

With the shield tunnel going deeper and deeper, the circumferential axial force becomes the governing factor rather than the bending moment. The hand hole acts as a weak point and initial damage in the segment joint especially when the circumferential axial force is extremely high. Despite the wide application of steel fiber or synthetic fiber in t|ie tunneling, limited researches focus on the structural responses of segment joint with macro structural synthetic fiber (MSSF). In this paper, a 1:2 reduced-scale experiment was conducted to study the structural perfonnance of the segment joint with different types of hand holes under ultra-high axial force. Special attention is paid to failure mode and structural performance (bearing capacity, deformation, cracking, and toughness). Moreover, segment joints with MSSF are also tested to evaluate the effects of MSSF on the failure mode and structural performance of the segment joints. The experiment results show that the hand hole becomes the weakest point of the segment joint under ultra-high axial force. A\/-type crack pattern is always observed before the final failure of the segment joints. Different types and sizes of the hand hole have different degree of influences on the structural behavior of segment joints. The segment joint with MSSF shows higher ultimate bearing capacity and toughness compared to segment joint with common concrete. Besides, the MSSF improves the initial cracking load and anti-spallling resistance of the segment joint.

关键词： shield tunneling structural synthetic fiber concrete hand hole segment joint ultimate bearing capacity crack pattern

Experimental and Numerical Investigation on the ultimate Strength of Stiffened Plates with Scanned Initial Geometrical Imperfection

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China Ocean Engineering 2019年第4期33卷 446-458页

作者： YU Yang-zhe FENG Guo-qing LI Chen-feng REN Hui-long College of Shipbuilding Engineering Harbin Engineering University

The study of the ultimate strength of stiffened plates is a hot topic in ocean engineering. The ultimate strength and behavior of collapse of stiffened plates were investigated using experimental and numerical methods. Two stiffened plates, with one and two half-bays in both longitudinal and transverse directions, were tested under the uniaxial compression. There were clamped boundaries at both ends of the stiffened panels and a restrained boundary on the transverse frames. The novel three-dimensional laser scanning technology was used to measure the initial geometric imperfections and the ultimate deformation of the stiffened panels after the test. The initial geometric deformation was imported into the finite element model, and the ultimate strength and behavior of collapse of the stiffened plates were calculated using the finite element analysis. FE analysis results based on the measured initial geometric imperfections were compared with the test results. It is concluded that structural deformation can be well measured by three-dimensional laser scanning technology, and can be conveniently imported into the finite element analysis. With the measured initial geometric imperfections considered, the FE analysis results agree well with the experimental results in ultimate strength, behavior of collapse, and the ultimate displacement distribution of the stiffened panels.

关键词： Stiffened plate ultimate strength experiment three dimensional laser scanning initial geometric imperfection

Evaluation of ultimate bearing capacity of Y-shaped vibro-pile

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Journal of Central South University 2008年第S2期15卷 186-194页

作者：王新泉陈永辉林飞卢孝益张霆 Key Laboratory of Ministry of Education for Geomechanics and Embankment Engineering Hohai University Geotechnical Research Institute Hohai University Jiangsu Provincial Communications Plan & Design Co. Ltd Zhejiang Provincial Plan Design & Research Institute of Communications

Based on Mindlin stress solution, a numerical computational method was proposed to calculate the stresses in the ground induced by side friction and the resistance of Y-shaped vibro-pile. The improved Terzaghi's and ЪерезанцевВГ's methods for ultimate bearing capacity evaluation were proposed by considering the stress strength induced by friction resistance at pile head level of Y-pile. A new method to calculate the ultimate bearing capacity of Y-pile was also proposed based on the assumptions of soil failure mode at the tip of Y-pile and the use of Mohr-Coulomb soil yield criterion and Vesic compressive correction coefficient with the induced stresses in the ground. Based on the comparisons with the field static load test results, it is found that the improved Terzaghi's method gives higher ultimate capacity, while the other two methods shows good agreement with the field results.

关键词： Y-shaped vibro-pile circular pile Mindlin stress solution ultimate bearing capacity of pile tip static loading test

Method for Calculating the ultimate Strength of Pitting Corrosion Ship Structural Plates Under Combined Loads

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Journal of Harbin Institute of Technology(New Series) 2018年第5期25卷 78-85页

作者： Lin Hua Fan Wh Jinlei Mu Xiaolong Ma School of Naval Architecture & Ocean Naval University of Engineering Wuhan 430033 China Naval Vessel Technical Evaluation Center for Hull Strucutre Strength Wuhan 430033 China

In order to solve the problem of calculating the ultimate strength of marine plate under pitting corrosion,the plate taking from marine with pitting corrosion was studied. Based on the data of pitting corrosion recorded,the concept of pitting corrosion characteristic element matrix was proposed to describe the distribution and the forms of pitting. Moreover,the model of sensitivity calculation was established to analyse the sensitivity of pitting corrosion characteristic elements for the ultimate bearing capacity of ship structural plate. A new approach was proposed to calculate the ultimate strength of pitting damaged ship structural plate under combined loads based on the factor of rigidity reduction. Simultaneously this new approach was proven to be validated by finite element simulation. Finally,formula of ultimate strength of pitting damaged ship hull plate was established by series of numerical calculations based on the approach,and the reliability of the formula was validated as well.

关键词： ship structure pitting damage ultimate strength combined loads sensitivity analysis

THE CRITERIA OF ultimate BOUNDEDNESS FOR NONAUTONOMOUS DIFFUSIVE LOTKA-VOLTERRA SYSTEMS IN TWO HETEROGENEOUS PATCHES

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Journal of Systems Science & Complexity 2001年第2期14卷 179-188页

作者： LI Xuezhi (Department of Mathematics, Xinyang Teachers College, Henan 464000, China) GENI Gupur (Deportment of Mathematics, Xinjiang University, Urumqi 830046, China) ZHU Guangtian (Institute of Systems Science, Academy of Mathematics and Systems Science, 信阳师范学院河南 464000 新疆大学新疆乌鲁木齐 830046 中科院系统科学所北京 100080

In this paper, a set of sufficient conditions is obtained for the ultimate boundedness of nonautonomous n-species diffusive Lotka-Volterra sub-models in two heterogeneous patches. The sub-models are the Lotka-Volterra tree systems, including the Lotka-Volterra chain systems and the Lotka-Volterra models between one and multispecies. The criteria in this paper are in explicit forms of the parameters and thus are easily verifiable.

关键词： ultimate boundedness diffusive Lotka-Volterra systems patches.

ultimate Physical Reality of the Universe

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Journal of Modern Physics 2018年第3期9卷 387-394页

作者： Moolathurai Rangasamy Vijayakumar Bharathiar University Coimbatore India

According to modern concepts, space continues in all directions, and has no known limits. The sun and billions of other stars make up a giant galaxy whirling through space. Countless other galaxies are scattered throughout space as far as man can see with the largest telescopes. The Newtonian uni-verse, Minkowski universe, Einstein’s General Relativistic Universe and the Big-Bang and Steady State models deal with creation and evolution of the universe. Following Einstein, Milne, Friedman, Lemaitre, De Sitter, Bondi and Gold, Hoyle, Narlikar and Brons Dicke have given their own models and tried to explain the nature of the universe. All the above mentioned concepts and models are not able to explain the ultimate Physical Reality of the Universe. Here I suggest for the first time, the ultimate Physical Reality of the Universe by explaining that there is no separate “space” without the presence of matter. I give the answer for the unexplained puzzling question: “What the universe expands into?” and explain that the universe is just closed and finite. I explain that the universe is ever expanding. I also give answers to important unan-swered questions so far.

关键词： ultimate Reality of the Universe

ultimate Strength of Completely Overlapped Joint for Fixed Offshore Wind Turbine Jacket Substructures

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Journal of Marine Science and Application 2019年第1期18卷 99-113页

作者： Wie Min Gho Ye Yang Maritime Production Research Pte.Ltd School of Civil and Environmental Engineering Nanyang Technological University Global Maritime Consultancy Ltd

This paper presents an innovative eccentric jacket substructure for offshore wind turbines to better withstand intense environmental forces and to replace conventional X-braced jackets in seismically active areas. The proposed eccentric jacket comprises of completely overlapped joint at every joint connection. The joint consists of a chord and two braces in a single plane. The two braces are fully overlapped with a short segment of the diagonal brace welded directly onto the chord. The characteristic feature of this joint configuration is that the short segment member can be designed to absorb and dissipate energy under cyclic load excitation. The experimental and numerical study revealed that the completely overlapped joint performed better in terms of strength resistance, stiffness, ductility, and energy absorption capacity than the conventional gap joints commonly found in typical X-braced jacket framings. The eccentric jacket could also be designed to becoming less stiff, with an inelastic yielding and local buckling of short segment member, so as to better resist the cyclic load generated from intense environmental forces and earthquake. From the design economics, the eccentric jacket provided a more straightforward fabrication with reduced number of welded joints and shorter thicker wall cans than the conventional X-braced jacket. It can therefore be concluded based on the results presented in the study that by designing the short segment member in accordance with strength and ductility requirement,the eccentric jacket substructure supporting the wind turbine could be made to remain stable under gravity loads and to sustain a significantly large amount of motion in the event of rare and intense earthquake or environmental forces, without collapsing.

关键词： Offshore wind turbine Jacket substructure Eccentric jacket Completely overlapped joint ultimate strength Cyclic loading Ductility Energy absorption

Behavior of Repairing Composite I-Section Beams with Opening under ultimate Torque

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Engineering（科研） 2018年第4期10卷 202-214页

作者： Ali Sabah Ahmed Al Amli Nadhir Al-Ansari Yaarub G. Abtan Civil Engineering Department Al Mustansiriyah Engineering College Al Mustansiriyah University Baghdad Iraq Lulea Technology University Lulea Sweden

An experimental study was conducted to investigate the behavior of composite concrete beams damaged and cracked under pure torsion, and then repaired by external strengthening. This was achieved using high strength Carbon Fiber Reinforced Polymer (CFRP) laminates bonded with epoxy four composite modify reactive powder concrete (MRPC) I-beams. Different types of section (Solid & with opening) were tested to obtain the effect of amount of CFRP laminate on beams ultimate torque behavior, angle of twist and failure modes. The results obtained showed that a significant effect of external high strength CFRP laminates on effectively restore of section solid, the range of 89.8% to 91.2% of ultimate torsional strength effectively restored as well as effectively restoring of section opening by 83.48% - 86.67% of ultimate torsional strength. The repaired beams give high efficiency in ultimate torsional strength, and indicate that the adopted technique gives a good torsional strength.

关键词： MRPC Repairing Carbon Fiber Reinforced Polymer (CFRP) ultimate Torsional Strength Composite Solid Opening

Study on ultimate Pullout Force of Grouting Anchors of the Anchor-Pull Retaining Wall

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Journal of Geoscience and Environment Protection 2014年第5期2卷 32-37页

作者： Hongbo Zhang Yifan Yu Xiuguang Song Yingyong Li Jianqing Wu School of Civil Engineering Shandong University Jinan 250061 China Subgrade Security Engineering Research Center of Shandong Province Jinan 250061 China

Determination of the grouting anchor pullout force is a key step during the design of anchor-pull retaining wall, but it is mostly determined relied on empirical formula at present, and the rationality and the safety cannot be effectively guaranteed. Based on the engineering case of the gravity retaining wall of Qinglin Freeway, the model test was designed, and combined with the results of the ABAQUS finite element numerical analysis, it was analyzed that how the anchor axial pulling force distributes. The results showed that the force of the anchor near the wall bolt was large and which far from the wall was small and the ultimate pullout force was proportional to the length, diameter and shear strength. When the end tension of the anchor was small, the top load played a leading role on the anchor tension. This conclusion confirmed the calculation formula of ultimate pullout force was and provided a theoretical basis for anchor-pull retaining wall design and calculation.

关键词： Anchor-Pull Retaining Wall ultimate Pullout Force Lateral Earth Pressure Model Test Numerical Analysis

A New Uniformly ultimate Boundedness Criterion for Discrete-Time Nonlinear Systems

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Applied Mathematics 2011年第11期2卷 1323-1326页

作者： Zhishuai Ding Guifang Cheng 不详

A new type criterion of globally uniformly ultimate boundedness for discrete-time nonlinear systems is introduced. In classical Lyapunov theory about globally uniformly ultimate boundedness, Lyapunov function is assumed to be positive definite and its difference at the every latter moment and the former moment is negative definite. In this paper the condition of difference of Lyapunov function is relaxed. Under the relaxed condition, the result of this paper can be considered as the extension of the classical Lyapunov theory about uniformly ultimate boundedness.

关键词： Uniformly ultimate Boundedness Lyapunov Function Discrete-Time Nonlinear Systems