Test And Numerical Simulation Research Of Static And Dynamic Characteristics In Cylindrical Concrete-like Material Specimen

Concrete material is a kind of typical brittle material. It is widely used in construction, traffic, water conservancy, airport pavement, municipal construction engineering and military industries to resistant penetration explosion fortifications and so on. As a kind of commonly used material, its dynamic and static mechanics performance has always been the hot spot of the domestic and foreign researc h scholars. It is simulated that the concrete materials parameters on the effect of static mechanical property in sensitivity and uncertainty propagation by using ABAQUS simulation software. It is discussed that static mechanics of concrete material based on mesoscopic model of interface and aggregate. It is contrasted and analyzed that the result which different strength of cement mortar specimen by SHPB experiment device and numerical simulation by ABAQUS software. The law is obtained that the material parameters and mesoscopic structure influence on the dynamic and static mechanical properties of concrete material.Firstly, hydrostatic numerical model is established based on ABAQUS. It is analyzed the sensitivity and uncertainty propagation of specimen size parameters, material parameters and the static contact parameters in the process of the static pressure. The result shows that:(1) The results of numerical simulation of the cement mortar bar specimen hydrostatic are in good agreement with the experimental results in this paper. The numerical simulation is reasonable and practical.(2)The lateral confining pressure produced by the friction effect is directly related to the length-diameter ratio. The sorting sensitivity parameters of specimens which the length-diameter ratio of 0.5 is D>μ>β>L>E. And the sorting sensitivity parameters of specimens which the length-diameter ratio of 2 is D>L>E>μ>β.(3)The discrete degree of pressure and displacement curve results of the specimens which the length-diameter ratio of 2 is smaller than the specimens results of the length-diameter ratio of 0.5 under static condition. It meets the design requirement that a rule in concrete materials under uniaxial static experimental. It verifies the rationality of the sensitivity and uncertainty transmission.Secondly, it is simulated that the specimens of containing spherical aggregates concrete and cement mortar on the base of mesoscopic mechanics. Numerical results that the existence of interface makes the correspond ing displacement of pressure peak of specimen smaller. It indirectly proofs there are many pore is firstly damaged under compression in the interface transition zone. And it is verified the macroscopic damage of concrete specimen is based on mesoscopic damage. The mesoscopic damage is fundamental cause of damage. At the same time specimens of macroscopic damage is the result of a mesoscopic damage accumulation and development.Finally, it is dynamic compression test that two kinds of cement mortar specimens which the strength of C25 and C45 on the SHPB testing device. And it is verified the effectiveness of the experimental data through the three wave method. The results show that:(1) The peak stress of cement mortar specimens which have the same dynamic compression strength increases with increasing strain rate in the SHPB dynamic compression experiment. And corresponding strain value of the peak stress decreased with increasing strain rate.(2) In the same strain rate, the peak stress increases with the increasing strength of the cement mortar specimen. It is compared that the experimental result and numerical simulation of stress-strain curve by ABAQUS software. The results are in good agreement. It is verified the effectiveness of numerical simulation in this thesis. T his thesis establishes the foundation for the numerical simulation for concrete materials further research.