Quantitative Analysis of Three-dimensional Fatigue Fracture Surface Reconstructed by Stereo Matching Method
Quantitative Analysis of Three-dimensional Fatigue Fracture Surface Reconstructed by Stereo Matching Method
复制标题
立体匹配法重建三维疲劳断裂面的定量分析
DOI：
10.2355/isijinternational.43.1453
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发表时间：
2003
影响因子：
1.8
通讯作者：
R. Kato
中科院分区：
文献类型：
--
作者：
Manabu Tanaka;Y. Kimura;L. Chouanine;J. Taguchi;R. Kato
采用由粗到细的立体匹配方法对Cu-Be合金（晶粒直径约为24 μm）疲劳断口进行了三维几何重建。然后在小于一个晶界长度（约14 μm）的尺度范围内，用盒计数法计算了从重建图像中提取的轮廓和断口轮廓的分形维数。等高线的分形维数的平均值约为1.238，在平行于裂纹扩展方向的平面（约为1.210）（平行方向）和垂直于裂纹扩展方向的平面（约为1.190）（垂直方向）上，与实际断裂面轮廓的分形维数接近。因此，立体匹配方法可以再现复杂断裂表面的三维图像。然而，重建的断裂表面轮廓的分形维数的平均值，（平行方向约为1128，垂直方向约为1.146）比实际断裂面轮廓略小，这是由于疲劳断裂面上存在悬突、碎片和微裂纹等微观结构特征，其通过立体匹配方法仅部分可再现。然而，通过三维断裂面重建和分析，可以获得大范围内给定断裂面的几何信息。将三维和二维分析相结合，可以进一步了解材料断裂面的几何特征和断裂机理。分形维数被认为是一个有用的指标，不仅表征断裂表面，但也比较的三维图像重建的结果与实际的断裂表面形态。
Three-dimensional geometry of a fatigue fracture surface in a Cu-Be alloy (the grain diameter is about 24 μm) was reconstructed by the stereo matching method based on the coarse-to-fine method. The fractal dimensions of the contours and of the fracture surface profiles extracted from the reconstructed image were then estimated by the box-counting method in the scale length range smaller than about one grain-boundary length (about 14 μm). The mean value of the fractal dimension of the contours was about 1.238, and was close to that of the actual fracture surface profiles in the plane in parallel with the crack growth direction (about 1.210) (in the parallel direction) and in the plane perpendicular to the crack growth direction (about 1.190) (in the perpendicular direction). Thus, the stereo matching method can reproduce the three-dimensional image of the complex fracture surface. However, the mean value of the fractal dimension of the reconstructed fracture surface profiles (about 1 128 in the parallel direction and about 1.146 in the perpendicular direction) was a little smaller than that of the actual fracture surface profiles, since there were microstructural features such as overhang, debris and microcracks on the fatigue fracture surface, which were only partly reproducible by the stereo matching method. Nevertheless, the geometrical information about a given fracture surface in a wide area can be obtained by the three-dimensional fracture surface reconstruction and analysis. Combination of three-dimensional and two-dimensional analyses may lead to the further understanding of the geometrical features of fracture surfaces and the fracture mechanism in materials. The fractal dimension was found to be a useful index not only for characterizing fracture surfaces but also for comparison of the result of three-dimensional image reconstruction with the actual fracture surface morphology.