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YIELD CRITERION IN PLASTIC-DAMAGE MODELS FOR CONCRETE

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Acta Mechanica Solida Sinica 2010年第3期23卷 220-230页

作者： Ji zhang Zhongxian zhang~★Chuanyao Chen (school of civil engineering and mechanics,huazhong university of science and technology, wuhan 43.074,china) [a] school of civil engineering mechanics Huazhong University of Science technology Wuhan 430074 China

A class of plastic-damage models for concrete require an unambiguous definition of cohesion in the yield criteria. For this reason, the Lubliner yield criterion has been adopted by many investigators and the commercial FE program Abaqus. As is well known, this criterion has achieved great success especially in plane stress states. In this paper, we are trying to extend it to triaxial compression stress states. First, a major limitation of the Lubliner criterion is analyzed. Then, a revised version of the Lubliner criterion is proposed, which shows appropriate properties over a wide range of stress states often encountered in engineering structures, and the predicted failure envelopes fit well with experimental data. For the concrete damaged plasticity model in Abaqus, a calibration strategy is suggested for uniformly confined concrete.

关键词： plastic-damage model Lubliner yield criterion triaxial compression concrete damaged plasticity

Statistical damage detection method for frame structures using a confidence interval

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Earthquake engineering and engineering Vibration 2010年第1期9卷 133-140页

作者： Li Weiming,Zhu Hongping~(++),Luo Hanbin~(++) and xia Yong~(++) school of civil engineering and mechanics,huazhong university of science and technology,wuhan 43.074,china ~+PhD Candidate ++ Professor school of civil engineering and mechanics Huazhong University of Science and Technology Wuhan China

A novel damage detection method is applied to a 3-story frame structure, to obtain statistical quantification control criterion of the existence, location and identification of damage. The mean, standard deviation, and exponentially weighted moving average （EWMA） are applied to detect damage information according to statistical process control （SPC） theory. It is concluded that the detection is insignificant with the mean and EWMA because the structural response is not independent and is not a normal distribution. On the other hand, the damage information is detected well with the standard deviation because the influence of the data distribution is not pronounced with this parameter. A suitable moderate confidence level is explored for more significant damage location and quantification detection, and the impact of noise is investigated to illustrate the robustness of the method.

关键词： damage detection standard deviation statistical method confidence interval noise

Early Age Compressive Strength of Pastes by Electrical Resistivity Method and Maturity Method

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Journal of wuhan university of technology(Materials science) 2011年第5期26卷 983-989页

作者：肖莲珍 school of Materials science and engineering Wuhan Institute of Technology

The compressive strength development of Portland cement pastes was investigated by the electrical resistivity method and the maturity *** experiments were carried out on the cement pastes with different water-cement ratios at different curing *** results show that the application of the maturity method has limitation to obtain the *** is found that both of the compressive strength and the electrical resistivity follow hyperbolic trend for all the *** hyperbolic equation of each mix is obtained to estimate the ultimate resistivity value which can probably be *** relationship between electrical resistivity and compressive strength of the cement pastes is established based on the test results and interpreted by the empirical Archie equation and a strength-porosity *** relationship between the electrical resistivity after temperature correction and the compressive strength was linear and independent of curing temperature and water-cement ratio.

关键词： electrical resistivity cement hydration compressive strength maturity method

A MODEL FOR CONCRETE DURABILITY DEGRADATION IN FREEZE-THAWING CYCLES

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Acta Mechanica Solida Sinica 2003年第4期16卷 353-358页

作者： Wei Jtm Wu Xinghao Zhao xiaolong (school of civil engineering and mechanics,huazhong university of science and technology,wuhan 43.074,china) Sch. of Civ. Eng. and mechanics Huazhong Univ. of Sci./Technology Wuhan 430074 China

Up to now,how to control the durability of concrete structures is still a pending research topic in civil *** to the fact that concrete durability can be affected by many non-mechanical factors,it is very difficult to research durability only based on mechanics. However,the phenomenon of failure caused by non-mechanical factors is similar to that caused by *** frost durability reflects the comprehensive durability of concrete in a certain sense, the specific failure process is analyzed and a damage model is introduced,which can describe the durability degradation process of concrete in the whole freeze-thawing cycle.

关键词： concrete durability damage frost durability

Numerical simulations and experimental investigations on transverse effects of two-wave mixing in a photovoltaic photorefractive crystal

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science china(Physics,mechanics & Astronomy) 2010年第5期53卷 856-863页

作者： CAI Xin1,2,LIU JinSong1 & WANG ShengLie1 1 wuhan National Laboratory for Optoelectronics,school of Optoelectronic science and engineering,huazhong university of science and technology,wuhan 43.074,china 2 school of science,wuhan university of technology,wuhan 430070,china 1. wuhan National Laboratory for Optoelectronics School of Optoelectronic Science and Engineering Huazhong University of Science and Technology Wuhan 430074 China2. School of Science Wuhan University of Technology Wuhan 430070 China

The transverse effects of two Gauss waves mixing in a photovoltaic photorefractive crystal,i.e.,the dynamical evolutions of signal beam with different parameters,are traced numerically and *** the one-dimensional numerical simulations and two-dimensional experimental investigations show that the self-focusing effect of signal beam becomes more obvious as the intensity of pump beam and the angle between the signal and pump beams *** accordance with these results,the state of two Gaussian waves mixing is controllable.

关键词： numerical simulation experimental investigation two-wave mixing transverse effects Gaussian distribution

Natural Frequency of Full-Prestressed Concrete Beam

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Transactions of Tianjin university 2007年第5期13卷 354-359页

作者：张耀庭李瑞鸽 school of civil engineering and mechanics Huazhong University of Science and Technology civil engineering Department Pingdingshan Institute of TechnologyPingdingshan 467001China

Dynamic tests of three bonded and two unbonded full-prestressed concrete beams were carried *** purpose was to seek the relation between prestressing force and natural *** results indicate that the frequency of prestressed concrete(PSC)beam increases with the increase in prestressing force *** results are different from the dynamic characteristics of isotropic material beam subjected to compressive axial force which were put forward by Clough et *** reason is that the beams were considered as isotropic,homogeneous,linear elastic material in the traditional analysis ***,more accurate results are required in the analysis of frequency of PSC *** constitutive mode of PSC member is analyzed based on microstructure of concrete in this *** orthotropic linear elastic mode is used to analyze the relation between dynamic frequency and prestressing force of concrete beam,at the same time the equivalent stiffness of prestressed tendon relating to the prestressing force is added to the bending deformation stiffness of the *** analytical value agrees well with the test result,indicating that the current analysis method in this paper is feasible to full-prestressed concrete beam.

关键词： full-prestressed concrete beam prestressing force natural frequency anisotropic material

Assessing a soft twin tunneling numerical model using field data

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Journal of Pharmaceutical Analysis 2009年第1期21卷 36-41页

作者： Ke-shuan Ma1,2,Lie-yun Ding11. school of civil engineering and mechanics,Hubei Key Laboratory of Control Structure, huazhong university of science & technology, wuhan 43.074, china 2. Department of civil engineering, Nanyang Institute of technology, Nanyang 473004, china. school of civil engineering and mechanics Hubei Key Laboratory of Control Structure Huazhong University of Science and Technology Wuhan 430074 China Department of civil engineering Nanyang Institute of Technology Nanyang 473004 China

Using a five-floor building affected by the Yangtze River highway tunnels in wuhan as the engineering background, we have constructed a free-field model and a coupled model to study the soil, lining, foundations and upper structure, and analyze the rules of movements of building foundation and ground induced by single tunnel and twin tunnel excavation with the Finite Element Analysis method. It is shown that for the coupled model, the longitudinal displacement of each foundation increases slowly when the tunnel face gets close to the foundation section and then increases fast when the tunnel face moves away from the foundation during the single and twin tunneling. For a single tunnel, the surface settlements are overestimated by the free-field and coupled tunnel. This might be crucial in urban areas. Regarding the maximum settlements and the width of the settlement trough, the difference between the free-field model and the coupled model is quite obvious. This comparison with the field measurement value reveals that the coupled model seems to be superior to the free-field model. These results are of instructive significance for design and excavation.

关键词： finite element analysis three-dimensional slurry shield tunneling building settlement

Thermal Effect of the Cable-Stayed Bridge Tower

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wuhan university Journal of Natural sciences 2003年第4A期8卷 1121-1125页

作者： zhang Hai-long, Li Jun, Liu Chang-guo, Jiang Tian-hua, Wei jun school of civil engineering and mechanics, huazhong university of science and technology, wuhan 43.074, Hubei, china huazhong university of science and technology School of Civil Engineering and Mechanics Wuhan Hubei China (GRID:grid.33199.31) (ISNI:***)

This paper studies the thermal effect of the cable-stayed bridge tower based on full time accurate measurement and finite element analysis on xiantao Hanjiang River Highway Bridge. The measured results and the displacement variation of top tower show that the tower rotates periodically when it is exposed in sunshine. But the tower column will not decline when there is no sunshine. In spite of in winter or in summer, the period when the tower column changed smallest is from 0∶00 am to 5∶00 am. The time period when the tower column has maximum deviation lags behind the time when the tower column has maximum temperature difference, and this phenomenon is obvious in winter. The conclusions also have directive value in predicting the tower deformations and their directions in construction control of cable-stayed bridge, and in verifying the finite element program.

关键词： bridge tower thermal effect deformation full time measurement

Focal mechanics and disaster characteristics of the 2024 M 7.6 Noto Peninsula Earthquake,Japan

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Frontiers of Structural and civil engineering 2024年第9期18卷 1378-1387页

作者： Guang-qi CHEN Yan-qiang WU Ming-yao xia Zhi-yuan LI school of civil and Transportation engineering Hebei University of TechnologyTianjin 300131China Graduate school of engineering Kyushu UniversityFukuoka 819-0395Japan The First Monitoring and Application Center China Earthquake AdministrationTianjin 300180China State Key Laboratory of Geohazard Prevention and Geoenvironment Protection Chengdu University of TechnologyChengdu 610059China

On January 1,2024,a devastating M 7.6 earthquake struck the Noto Peninsula,Ishikawa Prefecture,Japan,resulting in significant casualties and property *** information from the first six days after the earthquake,this article analyzes the seismic source characteristics,disaster situation,and emergency response of this *** results show:1)The earthquake rupture was of the thrust type,with aftershock distribution showing a north-east-oriented belt-like feature of 150 km.2)Global Navigation Satellite System(GNSS)and Interferometric synthetic aperture radar(InSAR),observations detected significant westward to north-westward co-seismic displacement near the epicenter,with the maximum horizontal displacement reaching 1.2 m and the vertical uplift displacement reaching 4 m.A two-segment fault inversion model fits the observational data well.3)Near the epicenter,large Peak Ground Velocity(PGV)and Peak Ground Acceleration(PGA)were observed,with the maxima reaching 145 cm/s and 2681 gal,respectively,and the intensity reached the highest level 7 on the Japanese(Japan Meteorological Agency,JMA)intensity standard,which is higher than level 10 of the United States Geological Survey(USGS)Modified Mercalli Intensity(MMI)standard.4)The observation of the very rare multiple strong pulse-like ground motion(PLGM)waveform poses a topic worthy of research in the field of earthquake engineering.5)As of January 7,the earthquake had left 128 deaths and 560 injuries in Ishikawa Prefecture,with 1305 buildings completely or partially destroyed,and had triggered a chain of disasters including tsunamis,fires,slope failures,and road ***,this paper summarizes the emergency rescue,information dissemination,and other disaster response and management measures taken in response to this *** work provides a reference case for carrying out effective responses,and offers lessons for handling similar events in the future.

关键词： Noto Peninsula Earthquake earthquake rupture mechanism earthquake disaster emergency response pulse-like ground motion