耦合压力加载对超声热激励效果影响研究  

Influence of coupling pressure loading mode on ultrasonic thermal excitation effect

作　　者：梁嘉辉 贾宇[1] 汤雷[1] 张盛行 LIANG Jiahui;JIA Yu;TANG Lei;ZHANG Shenghang(State Key Laboratory of Hydrology-Water Resources and Hydraulic Engineering,Nanjing Hydraulic Research Institute,Nanjing 210029,China)

机构地区：[1]南京水利科学研究院水文水资源与水利工程科学国家重点实验室,江苏南京210029

出　　处：《水利水运工程学报》2023年第3期104-110,共7页Hydro-Science and Engineering

基　　金：国家自然科学基金青年科学基金项目(52109162);中央级公益性科研院所基本科研业务费专项资金项目(Y421003;Y421007);国家重点研发计划项目(2021YFC3090104)。

摘　　要：耦合压力加载装置在超声激振中通过影响耦合压力,间接控制激励效果,从而影响超声激励红外热像技术探测效果。开展了耦合压力下混凝土微裂纹超声热激励试验,通过直接加载与铝合金限制装置加载的对比研究,分析900、1 200与1 500 N初始耦合压力作用下的微裂纹受激温度场。研究结果表明:相同初始耦合压力不同加载方式下,直接加载的混凝土温升效果优于铝合金限位装置。这是由于激振过程中铝合金加载装置对换能器作用了50%以上的附加力扰动增量,换能器等效电阻随之剧变,导致超声激励系统工作稳定性变差,进而弱化超声热激励效果。后续研究应弱化加载装置对激振换能器的力扰动,聚焦系统刚度适应换能器高频激振行为的耦合压力低扰动加载装置,实现超声激励系统声能量的高效输出。Coupling pressure is a key factor affecting the detection effect of ultrasonic excitation infrared thermography,and the coupling pressure loading device indirectly controls the excitation effect by influencing the coupling pressure in ultrasonic excitation.In this research,the ultrasonic thermal excitation test of concrete microcracks under different loading methods of coupling pressure was carried out,and the temperature field of microcracks under the action of 900,1200 and 1500 N initial coupling pressure was analyzed through the comparative study of direct loading and aluminum alloy limiting device loading,and it was concluded that the temperature rise effect of directly loaded concrete was better than that of aluminum alloy limiting device under different loading methods of the same initial coupling pressure.This is due to the fact that the aluminum alloy loading device acts on the transducer by more than 50%of the additional force disturbance increment during the excitation process,and the equivalent resistance of the transducer changes drastically,resulting in the deterioration of the working stability of the ultrasonic excitation system,and then weakening the ultrasonic thermal excitation effect.Subsequently,the force disturbance of the loading device on the excitation transducer should be weakened,and the coupling pressure low disturbance loading device with the stiffness of the system adapted to the high-frequency excitation behavior of the transducer should be studied to achieve the efficient output of sound energy of the ultrasonic excitation system.

关 键 词：超声热像 耦合压力 加载方式 热激励效果 

分 类 号：TU528[建筑科学—建筑技术科学]