Analysis Of Damage Process Of Concrete Members Under High Strain Rate By Reproducing Kernel Particle Method

The concrete members in the airport runway, bridge, pile sinking, dam and military defense project will bear to high strain rate effect which more than 102s-1 from aircraft landing, ship collision, hammer hit and blast, which cause damage and failure easily, it seriously threat to the safety of people’s life and property. Under this background, this paper selects the reproducing kernel particle method which is suitable for large deformation and high precision, and analyzes the damage process of the concrete member under high strain rate. It has important scientific significance and engineering application value.In this paper, the research progress of dynamic mechanical properties of concrete is studied. The main simulation method and the dynamic constitutive model of concrete are introduced and compared. On the basis of this, identify using the dynamic constitutive models of concrete HJC conduct the analysis of damage process of concrete members under high strain rate by reproducing kernel particle method. The main work and conclusions are as follows.1. We conduct the comparison and analysis of several common meshless methods and their characteristics. The theoretical formula, the algorithm and the integral scheme of the reproducing kernel particle method are studied. And the theory and parameter determination method of HJC dynamic constitutive model for concrete are studied. It lays a theoretical foundation for the realization of the reproducing kernel particle method.2. Based on VC6++, the method of reproducing kernel particle is developed. The processing method of essential boundary conditions is discussed. And the influence factors of the calculation accuracy are studied by the numerical example. The following conclusions are drawn: The mandatory conversion method has better stability and applicability in the treatment of essential boundary conditions; The calculation precision of the three B-spline kernel function is the highest in the three kinds of kernel functions; The radius of node influence domain is rmi=(1.2~1.8)dmax, the calculation accuracy is relatively high. The increase of the density of the node distribution can improve the accuracy of the calculation, but the computational cost also increases.3. For different situations, the damage cases of concrete members are established respectively, the damage processing of the concrete members under high strain rate is analyzed, the conclusions are as follows: The reproducing kernel particle method is suitable for the study of dynamic damage of concrete; The maximum stress ratio of concrete under high strain rate is increased by the standard compressive strength, and increases with the increase of strain rate. The damage and failure of concrete members are concentrated on the location of the high strain rate and cracks. The concrete material has a significant strain rate effect.