The near crack line analysis method was used to investigate a crack loaded by a pair of point shear forces in an infinite plate in an elastic-perfectly plastic solid. The analytical solution was obtained, that is the ...The near crack line analysis method was used to investigate a crack loaded by a pair of point shear forces in an infinite plate in an elastic-perfectly plastic solid. The analytical solution was obtained, that is the elastic-plastic fields near crack line and law that the length of the plastic zone along the crack line is varied with external loads. The results are sufficiently precise near the crack line and are not confined by small scale yielding conditions.展开更多
As one of the most important factors that determine the lifespan of a reinforced concrete structure, carbonation not only corrodes the reinforcing steel, but also changes the mechanical properties of concrete. For bet...As one of the most important factors that determine the lifespan of a reinforced concrete structure, carbonation not only corrodes the reinforcing steel, but also changes the mechanical properties of concrete. For better understanding the performance of carbonated concrete structure, it is necessary to study the mechanical properties of carbonated concrete. The strees strain relationship of carbonated concrete was analyzed on the basis of experiments. The specimens were made by means of accelerated carbonation and then compressed on the testing machine. Some very important characteristics of carbonated concrete were revealed by the testing results. In addition, a useful constitutive model of carbonated concrete, which proved to be suitable for analyzing carbonated concrete members, was established in this research.展开更多
Steel corrosion is the main occasion for durability degradation of concrete structures. For existing corrosion-expansion models of reinforcement, effects of stirrups were not considered, thus, they cannot entirely ref...Steel corrosion is the main occasion for durability degradation of concrete structures. For existing corrosion-expansion models of reinforcement, effects of stirrups were not considered, thus, they cannot entirely reflect the actual corrosion and expansion states. Based on uniform corrosion hypothesis and current models, a corrosion-expansion model for steel in concrete members is presented, which considered the effects of stirrups. Verification result of the model by test data indicates its full significance in structural inspection and life evaluation fields.展开更多
An interpolation method was used to solve the Volterra integral equation of the second kind caused by interaction among thermal, electric and mechanical fields. The exact expressions for the transient responses of str...An interpolation method was used to solve the Volterra integral equation of the second kind caused by interaction among thermal, electric and mechanical fields. The exact expressions for the transient responses of stresses, electric displacement and electric potential in an orthotropic piezoelectric hollow cylinder were obtained by means of the finite integral transforms. From the sample numerical calculations, it is seen that the present method is suitable for an orthotropic piezoelectric hollow cylinder subjected to arbitrary thermal shock, mechanical load and transient electric excitation. The result can be used as a reference to solve other transient coupled problems of thermo-electro-elasticity.展开更多
Bin-objective shape optimization of arch dam based on linear programming model is discussed to minimize both dam volume and maximal tensile stress.The importance of weight coefficient of the above two objectives is ch...Bin-objective shape optimization of arch dam based on linear programming model is discussed to minimize both dam volume and maximal tensile stress.The importance of weight coefficient of the above two objectives is chosen according to the value of importance ratio.The influence of weight coefficient to the optimization result is discussed in detail and the numerical example shows that both the model and method proposed is doable.展开更多
Many experimental results show that a wide class of ductile materials obey often nonlinear behavior, thus it is important to propose a nonlinear criterion describing nonlinear behavior of ductile material. A new nonli...Many experimental results show that a wide class of ductile materials obey often nonlinear behavior, thus it is important to propose a nonlinear criterion describing nonlinear behavior of ductile material. A new nonlinear yield criterion was proposed which gives a series of new failure criteria, establishes a relationship among various failure criteria, and encompasses previous yield criteria as special cases or approximations. The criterion is capable of being expressed in a simple mathematical expression and through a particular physical concept, it also agree with some experimental data. It may therefore serve as a possible admissible isotropic yield criterion.展开更多
A new fracture criterion was proposed. The physical explanation of the criterion is that crack will propagate when the minimum strain energy density in iso hoop stress curve reach a critical strength of the material c...A new fracture criterion was proposed. The physical explanation of the criterion is that crack will propagate when the minimum strain energy density in iso hoop stress curve reach a critical strength of the material considered. The resulting curve of critical fracture of mixed mode cracks shows that the present fracture is efficient and more accurate than the previous criteria.展开更多
The distribution of velocity is one of the basic issues in river dynamics.Based on the experimental data measured by ADV in the flume of State Key Hydraulics Laboratory (SKHL),this paper analyzed the ver- tical distri...The distribution of velocity is one of the basic issues in river dynamics.Based on the experimental data measured by ADV in the flume of State Key Hydraulics Laboratory (SKHL),this paper analyzed the ver- tical distribution of point velocity and the varying law of turbulence intensity in straight mobile compound chan- nel with an asymmetric floodplain.Above certain relative height,the streamwise point velocity follows the loga- rithmic distribution.Below the location,the velocity varies linearly approxim...展开更多
基金National Natural Science Foundation ofChina( No.5 98790 12 )
文摘The near crack line analysis method was used to investigate a crack loaded by a pair of point shear forces in an infinite plate in an elastic-perfectly plastic solid. The analytical solution was obtained, that is the elastic-plastic fields near crack line and law that the length of the plastic zone along the crack line is varied with external loads. The results are sufficiently precise near the crack line and are not confined by small scale yielding conditions.
文摘As one of the most important factors that determine the lifespan of a reinforced concrete structure, carbonation not only corrodes the reinforcing steel, but also changes the mechanical properties of concrete. For better understanding the performance of carbonated concrete structure, it is necessary to study the mechanical properties of carbonated concrete. The strees strain relationship of carbonated concrete was analyzed on the basis of experiments. The specimens were made by means of accelerated carbonation and then compressed on the testing machine. Some very important characteristics of carbonated concrete were revealed by the testing results. In addition, a useful constitutive model of carbonated concrete, which proved to be suitable for analyzing carbonated concrete members, was established in this research.
文摘Steel corrosion is the main occasion for durability degradation of concrete structures. For existing corrosion-expansion models of reinforcement, effects of stirrups were not considered, thus, they cannot entirely reflect the actual corrosion and expansion states. Based on uniform corrosion hypothesis and current models, a corrosion-expansion model for steel in concrete members is presented, which considered the effects of stirrups. Verification result of the model by test data indicates its full significance in structural inspection and life evaluation fields.
文摘An interpolation method was used to solve the Volterra integral equation of the second kind caused by interaction among thermal, electric and mechanical fields. The exact expressions for the transient responses of stresses, electric displacement and electric potential in an orthotropic piezoelectric hollow cylinder were obtained by means of the finite integral transforms. From the sample numerical calculations, it is seen that the present method is suitable for an orthotropic piezoelectric hollow cylinder subjected to arbitrary thermal shock, mechanical load and transient electric excitation. The result can be used as a reference to solve other transient coupled problems of thermo-electro-elasticity.
基金Sponsored by the National Natural Science Foundation of China(Grant.50139010).
文摘Bin-objective shape optimization of arch dam based on linear programming model is discussed to minimize both dam volume and maximal tensile stress.The importance of weight coefficient of the above two objectives is chosen according to the value of importance ratio.The influence of weight coefficient to the optimization result is discussed in detail and the numerical example shows that both the model and method proposed is doable.
文摘Many experimental results show that a wide class of ductile materials obey often nonlinear behavior, thus it is important to propose a nonlinear criterion describing nonlinear behavior of ductile material. A new nonlinear yield criterion was proposed which gives a series of new failure criteria, establishes a relationship among various failure criteria, and encompasses previous yield criteria as special cases or approximations. The criterion is capable of being expressed in a simple mathematical expression and through a particular physical concept, it also agree with some experimental data. It may therefore serve as a possible admissible isotropic yield criterion.
文摘A new fracture criterion was proposed. The physical explanation of the criterion is that crack will propagate when the minimum strain energy density in iso hoop stress curve reach a critical strength of the material considered. The resulting curve of critical fracture of mixed mode cracks shows that the present fracture is efficient and more accurate than the previous criteria.
基金Supported by Key Project of Chinese.Ministry of Education (03134)
文摘The distribution of velocity is one of the basic issues in river dynamics.Based on the experimental data measured by ADV in the flume of State Key Hydraulics Laboratory (SKHL),this paper analyzed the ver- tical distribution of point velocity and the varying law of turbulence intensity in straight mobile compound chan- nel with an asymmetric floodplain.Above certain relative height,the streamwise point velocity follows the loga- rithmic distribution.Below the location,the velocity varies linearly approxim...
