ABSTRACT To accurately size small crack-like flaws in components with non-ideal surface conditions, such as curvature, roughness, and coating, we developed a flaw sizing method based on an ultrasonic measurement model. First, the effects of surface curvature on the sound beam profile, as well as the effects of surface coating and roughness on the wave energy are investigated theoretically and experimentally. Then, correction methods for curvature, roughness, and coating are introduced into the ultrasonic measurement model, and the flaw response in components with different surface conditions is predicted. Lastly, by accounting for the effects of surface conditions, a set of model-based flaw sizing curves is generated for predicting the equivalent size of crack-like flaws. These model-based curves can guide the setting of system parameters and improve the flaw sizing accuracy. Experiments are then conducted to verify the effectiveness of the proposed method. This work demonstrates the utility of the ultrasonic method for measuring the equivalent flaw size in practical applications.

中文翻译：

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使用超声波测量模型测量通过非理想零件表面的小裂纹状缺陷

摘要 为了精确测量具有非理想表面条件（例如曲率、粗糙度和涂层）的部件中的小裂纹状缺陷的尺寸，我们开发了一种基于超声波测量模型的缺陷尺寸测量方法。首先，从理论上和实验上研究了表面曲率对声束轮廓的影响，以及表面涂层和粗糙度对波能的影响。然后，在超声测量模型中引入曲率、粗糙度和涂层的校正方法，预测不同表面条件下部件的缺陷响应。最后，通过考虑表面条件的影响，生成一组基于模型的缺陷尺寸曲线，用于预测裂纹状缺陷的等效尺寸。这些基于模型的曲线可以指导系统参数的设置，提高缺陷尺寸的精度。然后进行实验以验证所提出方法的有效性。这项工作证明了超声波方法在实际应用中测量等效缺陷尺寸的实用性。