超高分子量聚乙烯纤维/水性聚氨酯复合材料层压板抗软钢芯弹侵彻性能及其损伤机制

选用碳纳米粒子(CNPs)原位改性和未改性的超高分子量聚乙烯(UHMWPE)纤维作为增强纤维，水性聚氨酯(WPU)作为树脂基体，采用缠绕-复合-热压工艺制备单向(UD)正交结构的UHMWPE纤维/WPU复合材料层压板。基于X射线计算机断层扫描(CT)技术，研究UHMWPE纤维/WPU复合材料层压板在7.62 mm×39 mm软钢芯弹以弹速为(720±10) m/s侵彻下的弹道响应。结果表明，UHMWPE纤维的CNPs原位改性提高了CNPs-UHMWPE纤维/WPU复合材料层压板抗单发侵彻性能，但会降低其抗多发打击的能力。对于未被穿透的层压板，其被侵彻过程可分为三个阶段，依次为剪切冲塞、断裂破坏和剩余子层的塑性变形，且每个阶段的厚度比依次为11.51%、44.40%和44.09%；层压板的分层响应主要发生在第二阶段，并集中在弹着点附近；每发弹丸侵彻导致层压板的破坏区域包含在以弹着点为圆心、直径约为70 mm的圆内。 

Ballistic performance of ultrahigh molecular weight polyethylene fiber/waterborne polyurethane composite laminate against mild-steel core projectile and its damage mechanism

Two kinds of ultrahigh molecular weight polyethylene (UHMWPE) fiber, pristine and in-situ modified by carbon nanoparticles (CNPs), were used to prepare cross-ply unidirectional UHMWPE fiber/waterborne polyurethane (WPU) composite laminates by special process (winding, compound, and hot-pressing). The UHMWPE fiber/WPU composite laminates were impacted by mild-steel core projectile with size of 7.62 mm×39 mm at impacting velocity of (720±10) m/s. The ballistic behavior of UHMWPE fiber/WPU composite laminate was investigated by the X-ray computed tomography (CT) technology. The results show that the CNPs in-situ modification of CNPs-UHMWPE fiber may improve the single anti-penetration of its laminate, and this method may diminish the ability of resisting multiple strikes of its laminate. In addition, the penetration process of UHMWPE fiber/WPU composite laminate will be divided into three stages in a non-penetrating event: Shear plug, fracture failure and plastic deformation of the remaining sub-laminate. Moreover, the thickness ratios of every stages are about 11.51%, 44.40% and 44.09%, respectively. The delamination behavior of post-impact laminate is mainly distributed in the second stage, and approaches the impact point. Furthermore, the damage area of each projectile to the laminate may be contained in a circle with the impact point as the center and the dimeter of 70 mm.