Research On Dynamic Mechanical Property Of Hematite Concrete

In structural engineering, the dynamic mechanical properties for concrete materialstructureto resistdynamic load is of great significance.Hematiteconcrete is commonly used as a radiation protection structure,which especially used in the construction of nuclear power plant, such problems are due to the study of dynamic mechanical properties of concrete material, This paper tries to realize the hematite concrete rate effectby experiment which under impact loading, and by using Particle Flow Codethe test system is simulated,some relevant results are obtained.Firstly,by designing a batch of hematite concrete beam, this paper usesdrop-weight facility by changing the height and quality of drop hammer under different strain rate impact conditions to test three point bending specimen dynamic test, obtained akinds of mechanical parameters of the specimens time history curve.Secondly,by using high speed camera, the whole destructionprocess of the specimens are obtained,relationships betweenthe strain rate and hematite concrete flexural tensile strength, peak strain, the failure pattern is analyzed, so as to study the rate of hematite concrete rate effect.For the elastic impact conditions, we obtained the hematite concrete inherent frequency = 2100 Hz, natural frequency damping ratio = 2.8%;For impact damage condition, the strain rate range of 1.1 s-1-5.1 s-1are obtained.Analysis results show : with the increase of impact energy, peak load and strain of concrete growth rate increases, for the same height, which have the same impact duration, for the same quality, which shows that impact duration with the increase of height of reduced,Dynamic load increase factor(DIF) is roughly between 1.5-3.0, the DIF of concrete hematite flexural tensile strength is slightly higher than the ordinary concrete under uniaxial tensile strength, it shows that the hematite concrete has more sensitive than the normal concrete.Thirdly,in this paper, by using discrete element software PFC 2Dto simulate thedrop-weight facility, through the hematite coagulation of fundamental experimental results of beams of the parameter calibration, this paper compared the experimental and simulation data,the damage and fracture process of specimen, hematite concrete impact damage rule are comprehensivelyanalyzedunder different strain rate. Fourthly, by using PFC2 D on hematiteconcrete beam the result shows thewhole process of hematite has carried on thetrack,the crack and damage of themomen t, are nearly the same,the results prove that: the strain data was usedforbeam crack fracture analysis of the moment and the break time basic fracture analys is results are basically identical with the camera, which proves that the experi ment data analysis method are scientific.Finally, finished simula-tioncalculation of concrete beamshematite which under high-speed impact lo-ading, the predicti on results show that the hematite concrete beam under high strain rate loading are of a similar rateeffect with low strain rate loading...