The Damage Analysis Of Concrete And Its Engineering Application

Damage Mechanics, as the theoretic basis and measure of quantitative analysis which includes analysis of the intension capability of the engineering material and structure, the explanations of the destroying mechanism, forecast of invalidation and estimation of longevity and so on, is applied to analyze the intensity, distortion and destruction of the material and structure of concrete more and more broadly and reasonably. Concrete is a kind of inequality multiphase-compounding material which is constituted of rough aggregate and thin aggregate and cement and sand slurry. During the process of its formation, there exist many original cracks, and with the effect of the factors of load and so on, the original cracks will expand and combine continuously, and then create new cracks. We give the bad effect which is caused by these tiny limitations to the material of concrete a name-damage. It is proved by research that the destruction of concrete is the result of the gradual expansion of the interior tiny cracks, or we can say that destruction is only the last phase of the expanding process of the cracks. However, if we want to describe every capability of concrete authentically, we should study the evolvement rule of its interior tiny cracks, that is to analyze Damage Mechanics of concrete.This paper introduces and makes an inquiry into the application of Damage Mechanics to concrete and its structural intension, distortion and the analysis of destructing quality from macrocosmic to microcosmic, from static damage to dynamic damage , from isotropic damage to anisotropic damage, and from elastic damage to elastic-plastic damage and so on.This paper introduces the basic theory of Damage Mechanics and compares all kinds of damage evolvement models firstly. Thereafter, it extends two important problems of damage Theory, which are the matrix of elastic-plastic damage and its symmetric inference and the inference of parsing expressing formula of damage evolvement equation based on experiments. Also, the paper adopts the matrix of perpendicular anisotropic elastic damage to workout the FEM program of analyzing damage, and applies it to practical analysis. The part of analyzing dynamics damage advances a model of dynamics damage constitutive on the basis of experiments and the presupposition of the shape function. Then, considering the Mechanics quality of cyclic loading of concrete, the paper extends single-dimensional damage evolvement rule to multi-dimensional damage andanalyzes the failure of gravity dam under the effect of earthquake. At last, taking the inequality of material of concrete into consideration, the paper simulates a numerical value to the damage and rupture from fine-sight levels and demonstrates the rationality from the single-dimensional damage evolvement rule to the extension of multi-dimensional damage.