Acoustic Emission Localization Quantitative Analysis Of Damage Evolution Process Of Concrete Under Uniaxial Compression

The damage of concrete material,in essence,is the concrete in the process of making mixing,vibration is not enough to cause material internal damage.Under the action of external load,the micro-damage continuously accumulates,develops,penetrates and finally forms the macroscopic crack.By using the nondestructive testing technology to describe the internal micro-defects of concrete materials,the law of material damage evolution is analyzed,the types of material damage areas are divided,and the failure process of concrete structures with different aggregate particle sizes can be fully understood,which can provide a basis for correctly predicting the service life and structural reliability of concrete structures.In this paper,acoustic emission technology is used to detect the damage of concrete materials with different aggregate particle sizes under uniaxial compression loading.The damage evolution rule of concrete,damage region division and aggregate particle size on the impact of concrete damage evolution were studied.Based on the relationship between acoustic emission detection results and concrete damage,the rules of three stages of concrete damage evolution were numerically analyzed,and the thresholds of each stage were set,based on which the damage areas of concrete materials were divided.By means of numerical simulation,RFPA numerical damage simulation of concrete is carried out.This paper analyzes the causes of concrete damage and summarizes the law of damage development.By comparing the stress states of the damaged area and the non-damaged area in each stage,the stress characteristics of the damaged area and the non-damaged area are compared,and the development characteristics of the damaged area are obtained.By comparing the results of simulation and test,the feasibility and accuracy of improving the damage detection of concrete by acoustic emission technology are confirmed.