Based On The Deformation Field Measurement Of Quasi-brittle Materials Damage Model And Damage Law

The deformation field evolution of rock and concrete specimen is observed using digital speckle correlation method in this thesis. Based on the measured deformation field the failure problem of rock, concrete structure is studied.Firstly, it is proposed that the non-uniform indicator of the deformation field of non-structured rock, concrete specimen could be used to describe the damage of these materials. The damage constitutive equation of these materials is then able to be established based on the measured damage evolution. In order to verify the proposed method, uniaxial compress experiments are performed on one kind of rock specimen and one kind of concrete specimen. Results show the feasibility of this method. Compared with the traditional damage method, the proposed method could measure and obtain the damage variable and damage evolution of quasi-brittle materials much easier.The failure process of several complicated rock and concrete structures are experimentally studied and the evolution of the deformation filed during failure is inspected and analyzed using the digital speckle correlation method. The characteristics of failure process of the structures are analyzed based on the measurement results. The statistical indicator evolution of the deformation field is also studied. It is pointed out that this indicator might be used as a potential predictive for the forcasting of structure failure.