Determination of mode I dynamic fracture toughness of IM7-8552 composites by digital image correlation and machine learning
Determination of mode I dynamic fracture toughness of IM7-8552 composites by digital image correlation and machine learning
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DOI：
10.1016/j.compstruct.2018.11.089
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发表时间：
2019-02
影响因子：
6.3
通讯作者：
Rafael Cidade;Daniel S.V. Castro;E. Castrodeza;P. Kuhn;G. Catalanotti;J. Xavier;P. Camanho
中科院分区：
文献类型：
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作者：
Rafael Cidade;Daniel S.V. Castro;E. Castrodeza;P. Kuhn;G. Catalanotti;J. Xavier;P. Camanho
本文提出了一种计算动载荷下全场位移场j积分的光学实验方法。将该方法应用于测量纤维增强复合材料动态压缩载荷中的j积分，并计算与扭结带扩展相关的动态断裂韧性。采用数字图像相关的方法，计算了在分离式霍普金森压杆（SHPB）中动态加载的IM7-8552双边缘缺口层合板试样的修正j积分，该积分考虑了惯性效应。针对散斑参数的影响，进行了灵敏度研究。结果与采用不同数据约简方法得到的实验结果吻合较好，表明所研究材料在动载荷作用下存在上升的r曲线。此外，人们注意到惯性效应可以忽略不计，这表明动态平衡状态可以舒适地使用准静态方法。
An optical experimental procedure for evaluating the J-Integral from full-field displacement fields under dynamic loading is proposed in this work. The methodology is applied to measure the J-integral in the dynamic compressive loading of fiber-reinforced composites and to calculate the dynamic fracture toughness associated with the propagation of a kink-band. A modified J-Integral that considers inertia effects is calculated over the full-field measurements obtained by digital image correlation, for double edge-notched specimen of IM7-8552 laminates dynamically loaded in a split-Hopkinson pressure bar (SHPB). A sensibility study is conducted to address the influence of the speckle parameters. The results show good agreement with experimental observations obtained by using a different data reduction method, suggesting the existence of a rising R-curve for the studied material under dynamic loading. Furthermore, it was noticed that the inertia effect can be negligible, indicating a state of dynamic equilibrium in which quasi-static approaches may comfortably be used.