A new automated digital image‐based method for tracking both the position and shape of the crack front of delaminations in translucent glass fibre‐laminated test specimens is proposed. The method is applicable to both fracture toughness tests and fatigue tests. The digital image‐based algorithm identifies the newly formed crack area by the change in reflected light and then extracts both the crack front shape and the position. The method is used in a standard double cantilevered beam specimen test setup with the addition of light sources and a camera. The method does not rely on subjective test operator interpretations or calibrations. A reference pattern on the specimen is used to correctly map between the camera coordinate system and the specimen coordinate system, which makes the method insensitive to the camera position and camera or specimen movement during the test. Experimental test examples are provided, which shows that the whole crack front can be tracked with significantly higher accuracy than possible with existing methods.

中文翻译：

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一种基于数字图像的半透明玻璃纤维层压复合材料中分层前沿的自动跟踪方法

提出了一种新的基于数字图像的自动化方法，该方法可以跟踪半透明玻璃纤维层压测试样品中分层裂纹前沿的位置和形状。该方法适用于断裂韧性测试和疲劳测试。基于数字图像的算法通过反射光的变化识别新形成的裂缝区域，然后提取裂缝的前端形状和位置。该方法在标准的双悬臂梁试样测试装置中使用，并增加了光源和摄像头。该方法不依赖于主观测试操作员的解释或校准。标本上的参考图案用于在相机坐标系和标本坐标系之间正确映射，这使得该方法对测试过程中的相机位置以及相机或样品移动不敏感。提供的实验测试示例表明，与现有方法相比，可以以更高的精度跟踪整个裂纹前沿。