【摘要】 利用工业计算机层析技术(Computed Tomography,简称"CT")和自制的加载装置,实现了玻璃纤维增强复合材料试件三点弯曲加载过程的原位扫描,获取了不同加载阶段的CT图像。采用数字体图像相关法(Digital Volume Correlation,简称"DVC")测量分析了试件内部三维位移场和应变场,揭示了试件内部的应变演化特征及破坏机理。纤维增强复合材料内部细观结构特征可以作为变形信息的载体,实验中测量精度为0.063体素(2.8μm)。DVC获取的位移场及应变场分布能直观反映试件内部的结构特征,由横向切应变的分布显示出在试件破坏前已产生了剪切带,最终导致试件在该区域产生层间开裂。此外,由横截面位移分布验证了因横向切应力而导致截面产生翘曲的现象。结果表明,DVC法与工业CT结合所得测量结果能够直观地反映出复合材料内部结构的变形特征,为研究材料内部变形破坏及验证理论模型提供了新方法。更多还原

【Abstract】 A glass fiber reinforced composite specimen was scanned by using industrial Computed Tomography( CT) in situ,and CT images of the specimen under different loading were obtained. The digital volume correlation( DVC) technique was applied to calculating the three-dimensional displacement fields and strain fields in the specimen,and the strain evolution and damage mechanism were revealed. The microstructure of the fiber reinforced composite can be used as the carrier of deformation. The accuracy of the experiment is 0. 063 voxels( 2. 8 μm). The displacement field and strain field distribution obtained by DVC can reflect the internal structural characteristics of the specimen directly. With reference of the distribution of transverse shear strain,the shear band was formed before the specimen was broken,which eventually led to the interface delamination. In addition,the wrapping of the cross section due to the transverse shear was verified by the distribution of its displacement. These results show that the DVC method combined with CT can directly reflect the deformation characteristics of the internal structure of the composite,and provide a new method on studying the internal deformation and the failure of the material.更多还原