共查询到12条相似文献,搜索用时 0 毫秒
1.
A two-dimensional smeared crack model for reinforced concrete members is presented. Special emphasis is placed on the bond between concrete and reinforcement as the main factor influencing tension stiffening in cracked reinforced concrete. With the derived tangential stress-strain equations for concrete in the direction perpendicular to the cracks, the constitutive relationship for cracked reinforced concrete is established. Experimental specimens have been analyzed with the analytical model, and the analytical and experimental results are found to be in good agreement. 相似文献
2.
3.
4.
Temperature and Stress Analysis of An Experimental Model of Prestressed Lightweight Concrete Platform 总被引:3,自引:2,他引:3
—This paper presents an experimental study of a prestressed lightweight concrete platform mod-el with a tank and five steel columns.This platform can be used not only for extraction but also for storageof oil and is suitable for the Bohai Sea and other shallow seas of China.The platform is subjected to tem-perature.load.or both.The corresponding temperature distribution.strains.cracks.and vulnerable partsof the platform are analyzed respectively.By use of the finite element method and empirical formulas.thetemperature field of the model is analyzed.The results agree with the experimental results.thereby veri-fying the reliability of these two calculating methods.The paper provides an experimental basis for the de-sign of the bearing capacity and normal service state of prestressed concrete platforms. 相似文献
5.
6.
7.
Song Yupu Zhao Guofan Associate Professor Dalian University of Technology Dalian Professor Dalian University of Technology Dalian 《中国海洋工程》1991,(3)
The study of the behavior of concrete under biaxial stresses is essential to the design of offshore concrete platforms. Using the multiaxial test apparatus developed by the authors, the deformation and strength of concrete under biaxial stresses are studied experimentally. Based on the test data, an endochronic damage constitutive model and a failure criterion are proposed. According to the above model, an incremental nonlinear iterative programme is developed, and a plate sample in plane stress state is analyzed. 相似文献
8.
- 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
9.
Experimental studies on the friction coefficient between concrete and the top surface of a rubble mound foundation in China are reviewed. Through comparison of different test results, the development of this research is comprehensively analyzed. An experiment is carried out in the condition similar to prototype. The process curve of friction coefficient with the test block sliding is analyzed and a standard for determination of the friction coetfficient is defined. The variation features of the friction coefficient are analyzed on the basis of the present experimental results and other studies in China. It is shown that the friction coettfficient between concrete and the top surface of a rubble mound foundation decreases with the increase of the foundation pressure, and the friction coettqcient for a very fine leveling bed is smaller than that for a fine leveling bed. 相似文献
10.
11.
The effects of different lateral confinement stress on the fatigue behavior of and cumulative damage to plain concrete are investigated experimentally. Eighty 100 mm x 100 mm x 100 mm specimens of ordinary strength concrete are tested under constant- or variable-amplitude fatigue loading and lateral confinement pressure in two orthogonal directions. A fatigue equation is developed by modifying the classical Aas-Jakobsen S-N equation for taking into account the effect of the confined stress on fatigue strength of plain concrete. The results of variable-amplitude fatigue tests indicate that the linear damage theory proposed by Palmgren and Miner is unreasonable in the biaxial stress state. A nonlinear cumulative damage model that could model the effects of the magnitude and sequence of variable-amplitude fatigue loading and lateral confinement pressure is proposed on the basis of the evolution laws of the residual strains in the longitudinal direction during fatigue tests. The residual fatigue life predic 相似文献
12.
本文基于地面观测资料和NCEP/NCAR再分析数据,利用经验正交函数分析、线性回归分析等方法对1960—2016年夏季(6—8月)长江流域的极端高温(Extreme High Temperature,EHT)事件的强度、暖昼、暖夜发生日数的年代际特征及其对应大气环流进行分析,并探讨了EHT事件与大西洋多年代际振荡(Atlantic Multidecadal Oscillation,AMO)的关系。结果表明,中国夏季长江流域的极端高温事件存在明显的年代际变化特征,其中1960—1970年和2002—2016年为暖时期,1971—2001年为冷时期。相较于冷时期,暖时期在高温强度、暖昼和暖夜的发生日数方面均明显偏暖。针对于该极端高温年代际特征的成因,研究结果表明,暖时期位于长江流域北部的对流层中高层异常反气旋和偏北偏西的西太平洋副高有利于该地区下沉运动的增强,进而有利于极端高温的出现。同时,在对流层低层,位于中国东部的异常反气旋将低纬地区的暖湿气流携带至长江流域,这也有利于长江流域EHT事件的发生。此外,进一步分析表明,AMO与长江流域夏季EHT事件在年代际尺度上存在明显的关系,AMO超前中国夏季长江流域的EHT事件6~8 a,这对预测中国长江流域极端高温事件具有一定的指示作用。 相似文献