Application Of Concrete Damage Theory In The Simulation Of Hydraulic Structure

Under the load of some outer factors, there exists damage inside the concrete-structure, i.e., the concrete-structure is in a damage-field, and meanwhile the damage will develop further. It is unreliable to analyze on the concrete structures under the condition of non-damage. So, it is necessary and important to analyze the damage of the concrete-structures, so as to know the real mechanics or responding of the structures.So, it's important to pay more attention to the Concrete Damage Mechanics. Being based on the results researched by the Concrete Fracture and Damage Group of Hohai University, which is led by professor Xu Daoyuan, this paper studies on the application of Concrete Damage Mechanics in the damage simulation of hydraulic structures.After we analyze on the rupture mechanism of concrete material, the whole progress from the initial damage to the final damage inside the structure of concrete under the outer load or other outer factors is just a progress that the damage is formed and developed further. Using Damage Mechanics, it has been described that the stress-strain softening and the interweaving between the damage and fracture during the rupture of concrete.This paper presents three quantitative analyses of concrete damage and the method how to calculate the undamaged elastic modulus and undamaged strength. Because of the different properties when concrete is tensed and compressed, the translation relation of the tension damage and compression damage has been studied. The translation equation of the tension damage and compression damage cased by the same absolute value strain has been gained.An experimentation method has been designed, which can simulate the initial damage by mixed initiator into concrete. Using the elastic modulus of axial tension and compression experimentation, the initial damage D0 and damage threshold value Dfhave been gained.The size effect of concrete damage coefficient such as the initial damage D0 and damage threshold value Df has been studied. The translation relation of damage coefficient between the small and large specimens has been gained.The equation of damage finite element has been gained. The damage simulation calculation varied with load of concrete structure can be realized.After analysis on the method of the damage simulation, we have obtained the three dimensions' finite element equation of damage simulation. The damage simulation calculation of an arch dam has been calculated. The regular that the damage field varies with time gained in this paper are analyzed with concrete damage theory. Being based on the final results, the regular that damage change with time is different from one stress with time. So, this kind of damage-field may show correctly the work property of the concrete-structure. Finally, the usage age of dam can be estimated. So, we can say that the damage simulation calculation is very important and necessary.