弹道防护用超高分子量聚乙烯纤维增强热塑性树脂基复合材料的拉伸力学行为

以弹道防护用超高分子量聚乙烯(Ultra-high molecular weight polyethylene,UHMWPE)纤维增强热塑性树脂基复合材料作为研究对象，通过热压工艺制备单向正交结构的复合材料层压板。基于自主设计的拉伸试验装置，开展UHMWPE纤维增强热塑性树脂基复合材料在宏观尺度和准细观尺度上的面内拉伸试验，研究其面内拉伸力学性能及失效模式。研究结果显示：弹道防护用UHMWPE纤维增强热塑性树脂基复合材料在准细观尺度上的面内拉伸力学性能是其本征性能；随着偏轴角度的增加，拉伸断裂强度呈现指数型下降，这是由于失效模式由纤维的拉伸断裂破坏转变为纤维-树脂基体的界面破坏；此外，其在宏观尺度上的拉伸破坏强度比在准细观尺度上的拉伸断裂强度降低了50.52%，这是由于宏观尺度上的面内拉伸力学响应是其面内拉伸变形和层间分层破坏的耦合结果，即层压板的叠层效应。

Tensile mechanical behavior of ultra-high molecular weight polyethylene reinforced thermoplastic resin matrix composites for ballistic application

Ultra-high molecular weight polyethylene (UHMWPE) fiber reinforced thermoplastic resin matrix composites for ballistic application were selected as the research object. Composite laminates with unidirectional orthogonal structure were prepared by hot pressing process. Based on the self-designed tensile test device, the in-plane tensile tests of UHMWPE fiber reinforced thermoplastic resin matrix composite on macro and quasi meso scales were carried out to investigate its in-plane tensile mechanical properties and failure modes. The results show that the in-plane tensile mechanical properties of UHMWPE composites for ballistic application on quasi meso scale are their intrinsic properties. With the increase of off-axis angle, the tensile fracture strength decreases exponentially. This is attributed to the failure mode changing from the tensile fracture failure of fiber to the interfacial failure between the fiber and resin matrix. Furthermore, the tensile failure strength of UHMWPE fiber reinforced thermoplastic resin matrix composites on the macro scale is 50.52% lower than that on the quasi-meso scale, because the in-plane tensile mechanical response on the macro scale is the coupling result of in-plane tensile deformation and interlayer delamination failure, that is, the lamination effect of laminates.