在以往获得应用超声波定时方法测量裂纹高度的精确度和可靠性的初步数据基础上,本研究的主要目的是:(1)检查这些方法对测量倾斜缺陷的适用性:(2)以精确度达到±0.1mm 声程测量估价各种方法的精确度.结果表明,只要所使用的探头角度适当,所有超声波定时方法都具有较高的精确度。虽然表面波不适于测最倾斜缺陷,但如果只考虑精确度,则表面波传播方法是最佳的。超声法广泛应用于结构材料内部和表面缺陷的检验。应用断裂力学概念对评价结构完整性的应用推动了裂纹高度测量定量技术的研究,虽然反射脉冲振幅法已普遍用于测量裂纹高度,但是作为定量方法却存在较大的局限性,因为它易受到耦合因素、反射性以及缺陷角度或类型等变化的影响。因此,为改进裂纹尺寸的测量精度,推行了基于传播时间而不是反射脉冲振幅的测量技术。这种技术可以很精确地估计材料的厚度,这些方法实际上不受反射脉冲振幅变化的影响。已经提出了一系列采用体积波和表面波测定裂纹尺寸的技术。然而,这些技术看来 Based on the preliminary data obtained in the past on the accuracy and reliability of using the ultrasonic timing method to measure crack height, the main objectives of this study were: (1) to check the suitability of these methods for measuring tilt defects: (2) ± 0.1mm Sound path measurements evaluate the accuracy of various methods and the results show that all ultrasonic timing methods have high accuracy as long as the appropriate probe angle is used. Although surface waves are not suitable for measuring the most oblique defects, the surface wave propagation method is the best if only the accuracy is considered. Ultrasound is widely used in the inspection of structural materials and surface defects. The application of the concept of fracture mechanics to the evaluation of structural integrity has promoted the study of quantitative measurement of crack height. Although the reflected pulse amplitude method has been widely used to measure the crack height, there is a big limitation as a quantitative method because it is susceptible to Coupling, reflectivity and the angle or type of defects and other changes. Therefore, in order to improve the measurement accuracy of the crack size, a measurement technique based on the propagation time instead of the reflected pulse amplitude was introduced. This technique allows for a very accurate estimation of the thickness of the material and these methods are practically immune to changes in the amplitude of the reflected pulse. A series of techniques have been proposed for measuring crack size using bulk and surface waves. However, these technologies seem