Deformation and failure of laminated fabric fiber-glass reinforced plastic during bending on an annular support: effect of 3D reinforcement and loading rate
Abstract:
Felting is a needle-punching technology in which the impacts of barbed needles partially damage the dry fibers of the fabric stack and pull them normally to the surface. The result is transversal reinforcement at a given impact density per 1 cm$^2$ in the local area. In this work, the effect of felting on the resistance to bending on the annular support of laminated fabric fiber-glass reinforced plastic at various loading rates is experimentally studies. During quasi-static tests, the area of defects observed by the backlit of the specimens with felting decreases by approximately 20% compared to the specimens without felting at indenter diameters of 10 and 20 mm.
During the low-velocity impact tests, the damaged area decreases on average by 9% (velocity is 1.93 m/s) and 15% (velocity is 2.4 m/s) with felting at an indenter diameter of 10 mm. For a diameter of 20 mm, the damaged area with felting also decreases compared with the specimens without felting (by 11% at 1.42 m/s, by 22% at 1.98 m/s, and by 34% at 2.42 m/s). The experimental results show that even the minimum density felting (10 cm$^{-2}$) significantly reduces the delamination area (up to 34%) during a local impact. The authors are grateful to A.V. Nikonov, M.V. Zhikharev and A.V. Bezmelnitsyn for assistance in preparing the specimens.
Keywords:fabric fiber-glass reinforced plastic, three-dimensional reinforcement, bending on the annular support, static loading, low-velocity impact.
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