Application Of Cellular Automata To The Simulation Test Of Concrete Under Dynamic Load

The material inhomogeneity, discreteness and the fractures between the material borders result in complicated mechanical character of concrete. The research in concrete on macro level is to consider it as homogeneous and continuum material, which exhibits favorable applicability in mechanical character research of concrete under static load.The concrete material under impact load and static load exhibits different characteristics. Impact test is the main approach to study dynamic mechanical properties of concrete, but there are many deficiencies such as high cost, high requirement of shape and dimension, difficult control of load-applying and etc, moreover, the limits of test equipment and technology lead to great discreteness of experimental dates. In conventional numerical simulation tests, large amount of elements is necessary to describe these defects; the detailed and complex calculation is a time-consuming work.Based on the Cellular Automata theory, Multiple Random Equivalent Truss Model provides a new approach to describe the mechanical character of concrete under dynamic load by means of increasing connections between elements rather than the amount of elements, this model can describe the material inhomogeneous on a microscopic level, which will also leads to the reduction of elemental amount and calculation time.Thorough research has been performed in this article about the parameters in Multiple Random Equivalent Truss Model under dynamic load: the ultimate strength of model rods, the variance of rod strength distribution, the elastic modulus of rods, the coefficient of damping; after the summary of the effect rule of these parameters, one model of concrete under uniaxial dynamic load and an other under triaxial dynamic load are built to simulate failure process of experiments. The results are consistent with that of experiment, which shows the rationality and validity of the models and verifies the applicability of Multiple Random Equivalent Truss Model in representing the mechanical property of concrete. The study in this paper will provide some basic theory for further research of simulation of concrete under dynamical load.