Wavelet based crack detection has certain limitations such as, border distortion near the ends of a signal and the requirement of high measurement resolution. Border distortion restricts the crack detection near the ends of a beam. Detecting crack near the fixed end is critical as it faces the highest bending stresses. High measurement resolution is required for better localization of cracks and also to shrink the border distortion zone. In the present work, the effect of measurement resolution and wavelet scale on the border distortion is studied. Suitable wavelet scale is selected based on crack localization and smoothness of wavelet coefficients. The effect of measurement resolution on signal extension using isomorphism is presented. Photographic method is used to obtain the high resolution measurement of the beam deflection. The algorithm is tested for the detection of a crack in the border distortion zone. Also, the detection of two simultaneous cracks in the beam is presented.

基于小波的裂缝检测具有某些局限性，例如，信号末端附近的边界变形以及对高测量分辨率的要求。边界变形将裂纹检测限制在梁的末端附近。检测固定端附近的裂纹至关重要，因为它会面临最高的弯曲应力。需要较高的测量分辨率才能更好地定位裂纹，并缩小边界变形区域。在目前的工作中，研究了测量分辨率和小波尺度对边界失真的影响。根据裂纹的局部性和小波系数的平滑度选择合适的小波尺度。提出了测量分辨率对使用同构的信号扩展的影响。摄影方法用于获得高分辨率的测量结果。光束偏转。测试该算法以检测边界变形区域中的裂纹。此外，介绍了光束中同时出现的两个裂纹的检测。