本文研究了激光散斑照相放大技术和夹层散斑技术。激光散斑照相放大技术可以用来测量裂端附近一毫米范围内的应变分布。夹层散斑技术便于用来测量应变分布随加载过程的变化。应用这两种技术,我们测出了裂端附近1.7mm×1.5mm范围内的应变场及其随加载过程的变化,并提供了实验结果。此外,我们还提供了裂纹扩展过程中裂端前方不断出现小孔现象的照片。 In this paper, laser speckle photography magnification technique and sandwich speckle technique are studied. Laser speckle photographing magnification can be used to measure the strain distribution within a one millimeter range near the crack tip. Intercalated speckle techniques are readily used to measure changes in strain distribution with loading. Using these two techniques, we have measured the strain field in the range of 1.7 mm × 1.5 mm near the crack tip and its variation with the loading process, and provided the experimental results. In addition, we also provide photographs of small holes that appear in front of the crack tip during crack propagation.