Numerical Investigation On Failure Mechanisms Of Concrete Structures

The complex deformation and failure process of concrete structure is a great challenge for many researchers from engineering mechanics and materials science to devote them to it. It is prone to study the no-linear mechanics behavior nature and the failure mechanics, estimate the safe state of the concrete structure engineering. So it is of great importance and significance to investigate the deformation and failure process of concrete structures.Laboratorial tests and in-situ observations have been an effective and direct waysof studying the failure process of concrete structures failure, and these ways play acrucial role in the study of material failure process. But because of the limitation ofthe resource on the manpower, substance, finance, so there is some limitation on thelaboratorial tests and in-situ observations. Analytical method such as mathematics andengineering mechanics is also important in investigating the stress-strain relation andthe induced acoustic emission by some simplifications to materials. However, themathematical and mechanical methods are seemed to be weak in dealing with thecomplex interactions among micro-cracks and the local failure due to theheterogeneities. As a result, numerical method, a most widely used and effectivemethod, can serve as a tool to study the failure process of concrete structure. Theproblems in concrete failure mechanics and engineering are of three-dimension tosome extent. Many concrete mechanical problems, except plain strain problems andplain stress problems are also related to many directions and cannot be simplified totwo-dimension due to the heterogeneities of the materials.Firstly, based on the microscopic structures and constitutive relation of concrete on a meso-level, the whole failure process of concrete structure can be solved combined with computational mechanics and statistics. Stochastic functions, including Weibull distribution function, by introducing heterogeneity of mechanical properties of materials into the model, MFPA3D can simulate non-linear deformability of a quasi-brittle of ductile failure behavior with a simple constitutive law for the local material. By introducing a reduction of material parameters after element failure, it can simulate strain-softening and discontinuum mechanics problems in a continuum mechanics mode. In addition, the quick development of computer hardware and computational mechanics make it a powerful tool to...