倍增云纹的显微测量及密集云纹场的应变测算

为了提高云纹法的准确度,文中提出了使倍增后的云纹宽度变细并进行显微测量的技术,以及由密集云纹场测算应变的条纹间距插值和小间距均匀法。给出了估计由此法算得的应变的误差及其修正方法。所做的曲杆实验其数据与理论值符合得很好。文中还将云纹法中闪耀光栅与振幅栅相匹配的光学空间滤波系统改进为实时系统,导出其条纹倍增率及云纹图的最佳对比度条件。     

The micro-connection of the second-order moiré fringes and its order determination,and the determination of the boundary strains

The micro-connection method for determining the centre lines of second-order moiré fringes presented in this paper can enhance the accuracy in measuring strain fields, and generally can determine the absolute order of the second-order moiré fringes. The strain data obtained from curved beam experiment are in good accordance with theory. The relationship between the second-order moiré fringe and the strains at the specific points of the specimen is derived. Hence a reciprocate shift method is presented for determining strain distributions in the non-overlapping region of the shifted moiré patterns, (usually in the region of specimen where no second-order moiré fringes occur is the boundary region).