High Spatial Resolution Internal Stress Testing and Analysis of Fiber Optic Winding Structure Using BOTDA

This paper proposes a distributed stress analysis method for fiber winding structures. Compared with the traditional single-layer method, we quantitatively calculated each turn's stress in the fiber stacking state, including the inclination angle, endplate, and layer transition. BOTDA tested the internal stress at high spatial resolution, which is consistent with the distributed method. The results proved the attenuation of internal stress under fiber stacking state in different winding parameters. For the first time, quantitative analysis of the stress increase characteristics of layer transition has been realized. At last, the discussion of rewinding, tension dropout, and extrusion defects provides a non-destructive and rapid method for defect recognition and winding quality improvement.