Numerical Simulation For Crack Propagation Process In Concrete Gravity Dam

In actual engineering, No matter how rigorous crack control measures are taken,The concrete gravity dams still work with cracks. Therefore, The influence of cracking on the safety of the dam is greatly concerned by the researchers. This paper mainly discusses this problem,The theory of concrete fracture mechanics is adopted in the analysis of concrete gravity dam,The carrying capacity and fracture behavior of cracking dams are studied,and also provide a gist for the safety evaluation of concrete gravity dam.Numerical simulation of crack propagation is considered as a rough problem in numerical analysis of solid mechanics,for element dynamic regulation and nonlinearities of material soften. This paper achieve arbitrarily crack propagation of concrete gravity dam by using the finite element software ANSYS,by its powful finite element mesh,fracture solution module and optimized solver. The main work of this paper are as follows:1,By utilizing I-II mixed mode Crack Propagation Criterion of concrete,2D arbitrarily crack propagation comes true by using APDL(ANSYS parameter design language).The main features of this numerical method are:1) Utilizing the crack initiation propagation criterion which has explicit physical meaning to assess the stability and direction of the crack propagation;2) Using Fictitious Crack Model;3) Crack length control method is applied in whole propagation process. Later,The P-CMOD curve and crack propagation path are obtained by this numerical method, It shows that numerical results are quite close to experiment results. As a result,This method is effective to simulate crack propagation of concrete gravity dam.2,By utilizing the above algorithm, The influence on carrying capacity and fracture behavior of real dams,for upstream crack of different length and locations, are researched in this paper. When considering the hydrostatic pressure, deadweight and water pressure inside crack,The numerical results shows: 1) The dam fracture analysis can't neglect the action of water pressure inside cracks. And the problem of hydraulic fracturing in dam would be likely to appear; 2 ) For cracks which length are less than 5 m, No matter where the location, The water lever when crack initiation is greater than crest elevation(80m), The max water lever is about 1.1 times as high as crest elevation; 3) The carrying capacity of dam firstly increase to peak load,and then gradually decrease. However, There is a process of the destruction, The bearing capacity of dam won't be sharply decrease because of the long growth-crack(such as: 10m); 4) Cracks would expansion to bottom or downstream side of the dam.