Based on reanalyzing test results of uniaxial compressive behavior of concrete at constant high temperatures in China, with the compressive cube strength of concrete from 20 to 80 MPa, unified formulas for uniaxial co...Based on reanalyzing test results of uniaxial compressive behavior of concrete at constant high temperatures in China, with the compressive cube strength of concrete from 20 to 80 MPa, unified formulas for uniaxial compressive strength, elastic modulus, strain at peak uniaxial compression and mathematical expression for unaxial compressive stress-strain relations for the concrete at constant high temperatures were studied. Furthermore, the axial stress-axial strain relations between laterally confined concrete under axial compression and multiaxial stress-strain relations for steel at constant high temperatures were studied. Finally, based on continuum mechanics, the mechanics model for concentric cylinders of circular steel tube with concrete core of entire section loaded at constant high temperatures was established. Applying elasto-plastic analysis method, a FORTRAN program was developed, and the concrete-filled circular steel tubular （CFST） stub colunms at constant high temperatures were analyzed. The analysis results are in agreement with the experiment ones from references.展开更多
The mechanism of transport of chemicals in soil is an important research topic of environmental science and engineering, and some models and methods for a variety of solute transport problems have been done. Howeve...The mechanism of transport of chemicals in soil is an important research topic of environmental science and engineering, and some models and methods for a variety of solute transport problems have been done. However. most of previous works are usually for a soil column of infinite dimension. Starting from the one-dimension transient solute transport equation and its boundary and initial condition for a solute transport problem of soil column of finite length, this work has successfully applied a variable transformation to simplify the partial differential equation of solute transport problem. And an analytical serial solution for the simplified equation is then established by the so-called separated variable method and the superposition method. Compared with numerical methods such as finite different method and finite element method, this analytical solution is more accurate and of higher computation efficiency. In addition, the solution procedure presented could be extended for applications such as quality analysis, design of physical experimentation, or parameter estimation and measurement of solute transport problems.展开更多
基金Projects(50438020 50578162) supported by the National Natural Sceince Foundation of China
文摘Based on reanalyzing test results of uniaxial compressive behavior of concrete at constant high temperatures in China, with the compressive cube strength of concrete from 20 to 80 MPa, unified formulas for uniaxial compressive strength, elastic modulus, strain at peak uniaxial compression and mathematical expression for unaxial compressive stress-strain relations for the concrete at constant high temperatures were studied. Furthermore, the axial stress-axial strain relations between laterally confined concrete under axial compression and multiaxial stress-strain relations for steel at constant high temperatures were studied. Finally, based on continuum mechanics, the mechanics model for concentric cylinders of circular steel tube with concrete core of entire section loaded at constant high temperatures was established. Applying elasto-plastic analysis method, a FORTRAN program was developed, and the concrete-filled circular steel tubular （CFST） stub colunms at constant high temperatures were analyzed. The analysis results are in agreement with the experiment ones from references.
基金Acknowledgements： The work was supported by the National Natural Science Foundation of China （No. 90502006/D0123）, Hunan provincial Natural Science Foundation of China （No. 06JJ3020） and Scientific Research Fund of Hunan Provincial Education Department （No. 06C500）.
文摘The mechanism of transport of chemicals in soil is an important research topic of environmental science and engineering, and some models and methods for a variety of solute transport problems have been done. However. most of previous works are usually for a soil column of infinite dimension. Starting from the one-dimension transient solute transport equation and its boundary and initial condition for a solute transport problem of soil column of finite length, this work has successfully applied a variable transformation to simplify the partial differential equation of solute transport problem. And an analytical serial solution for the simplified equation is then established by the so-called separated variable method and the superposition method. Compared with numerical methods such as finite different method and finite element method, this analytical solution is more accurate and of higher computation efficiency. In addition, the solution procedure presented could be extended for applications such as quality analysis, design of physical experimentation, or parameter estimation and measurement of solute transport problems.
