摘要
超声波法广泛应用于混凝土无损检测,但超声波在混凝土中传播时能量损耗非常快。本文为研究超声波在混凝土中的传播和能量损耗规律,利用MATLAB编写程序建立细观结构数值混凝土模型,再将模型导入到COMSOL有限元软件中模拟超声波在混凝土中的传播。通过对不同参数的模拟,研究孔隙、骨料体积分数以及发射频率对超声波能量损耗的影响。研究表明:混凝土中孔隙虽然很小,但却是超声波能量损耗的主要因素;超声波能量随传播距离的增大呈指数衰减,且超声波发射频率越高衰减越快;骨料含量对超声波能量损耗影响不大,但能引起复杂的反射和散射,增加裂缝、孔洞等缺陷的识别难度。
Ultrasonic method is widely used in concrete nondestructive testing,but the energy loss of ultrasonic wave in concrete is very fast.In order to study the law of ultrasonic propagation and energy loss in concrete,a program was wrote by MATLAB to establish a meso-structure numerical concrete model,and then the model was imported into COMSOL finite element software to simulate the propagation of ultrasonic in concrete.Through the simulation of different parameters,the effects of pores,aggregate volume fraction and emission frequency on ultrasonic energy loss were studied.The research shows that although the pores in concrete are very small,they are the main factor of ultrasonic energy loss.The ultrasonic energy decays exponentially with the increase of propagation distance,and the higher the ultrasonic emission frequency is,the faster the attenuating speed is;The aggregate content has little loss of ultrasonic energy,but it can cause complex reflection and scattering,which increases the difficulty of identifying cracks,holes and other defects.
作者
卢青
Lu Qing(South China University of Technology,Guangzhou 510640,China)
出处
《特种结构》
2022年第5期95-100,共6页
Special Structures
关键词
数值混凝土模型
超声波
能量衰减
Numerical concrete model
Ultrasonic wave
Energy attenuation