摘要
水轮机顶盖螺栓服役时承受复杂载荷的作用易发生安全事故,因此对顶盖螺栓的预紧力检测已成为保障水轮机安全运行的必备手段。针对目前尚缺少顶盖螺栓超声应力检测仿真、轴向应力分布对检测的影响等问题,引入有效应力系数并提出螺栓预紧力的非线性超声检测方法。即首先建立顶盖螺栓的应力超声检测有限元模型,通过静态分析得到螺栓的轴向应力分布特征及预紧力和夹持距离对分布特征的影响,从而得到有效应力系数的表达式;再通过不同预紧力下的超声波传播的仿真,标定有效应力系数;最后使用标定公式进行螺栓预紧力试验,测量结果误差在±4%以内,证明了该顶盖螺栓预紧力超声检测方法的可靠性。
The top cover bolts of hydraulic turbine are subjected to complex loads in service and are prone to safety accidents,so the preload detection of top cover bolts has become a necessary means to guarantee the safe operation of hydraulic turbine.Aiming at the lack of simulation research on ultrasonic stress detection of top cover bolts and the influence of axial stress distribution on detection,this paper introduces the effective stress coefficient and proposes a nonlinear ultrasonic detection method for bolt preload.First of all,the finite element model for ultrasonic stress detection of top cover bolts is established.The axial stress distribution characteristics of bolts and the influence of preload force and clamping distance on the distribution characteristics are obtained through static analysis,so as to get the expression of effective stress coefficient.Then the effective stress coefficient is calibrated through the simulation of ultrasonic wave propagation under different preload forces.Finally,the bolt preload test is carried out using the calibration formula,and the error of the measurement results is within±4%,which proves the reliability of the ultrasonic detection method of the preload force for the top cover bolt.
作者
樊志远
邢涛
赵飞翔
徐敏玉
FAN Zhi-yuan;XING Tao;ZHAO Fei-xiang;XU Min-yu(College of Mechanical and Electrical Engineering,Northeast Forestry University,Harbin 150006,China)
出处
《水电能源科学》
北大核心
2024年第7期165-168,173,共5页
Water Resources and Power
关键词
顶盖螺栓
有效应力系数
非线性
超声波
top cover bolt
effective stress coefficient
nonlinearity
ultrasonic
