In this study, low velocity impact behavior of E-glass fiber-reinforced thermoplastic composites repaired by pressing external laminated composite patches was investigated by experimental methods. Thermoplastic composites were manufactured from polypropylene granules with two different fiber contents of 40 wt. % and 60 wt. %. Repaired specimens were prepared by using unidirectional E-glass reinforced polypropylene based thermoplastic prepregs. In order to compare the low velocity impact behavior of the repaired and unrepaired specimens, a number of single impact tests (ranging from energy levels of 10 J to 50 J) were carried out through a drop weight impact test machine with a hemispherical impactor. Low-velocity impact response of the specimens was investigated with cross-examining contact force-deformation curves and damaged specimens. Impact damages occurred in the upside and bottom surfaces of the composites were recorded from the visual inspection and compared for repaired and unrepaired specimens. According to experimental results, bending stiffness and maximum contact force of the specimens having fiber content of 60 wt.% are higher than those of 40 wt.%. Moreover, it was concluded that the patch repaired specimens have achieved a better performance in terms of maximum contact force and absorbed energy compared to the intact specimens.

中文翻译：

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复合补片修复热塑性复合材料低速冲击性能的实验研究

在本研究中，通过实验方法研究了通过压制外部层压复合材料补片修复的无碱玻璃纤维增​​强热塑性复合材料的低速冲击行为。热塑性复合材料由聚丙烯颗粒制成，两种不同的纤维含量为 40 重量％。% 和 60 重量。%。通过使用单向 E 玻璃增强聚丙烯基热塑性预浸料制备修复样品。为了比较修复后和未修复样品的低速冲击行为，通过带有半球形冲击器的落锤冲击试验机进行了许多单次冲击试验（从 10 J 到 50 J 的能量水平）。通过交叉检查接触力-变形曲线和损坏的试样，研究了试样的低速冲击响应。通过目视检查记录复合材料上下表面发生的冲击损坏，并比较修复和未修复的样品。根据实验结果，纤维含量为 60 wt.% 的试样的弯曲刚度和最大接触力高于 40 wt.% 的试样。此外，得出的结论是，与完整试样相比，修补后的试样在最大接触力和吸收能量方面取得了更好的性能。