【摘要】 针对高速列车玻璃钢外包围结构抗异物冲击性能提升需求，开展了聚脲增强玻璃钢复合材料的力学特性与冲击损伤机理研究；通过准静态拉伸试验测定了聚脲和玻璃钢材料的力学性能参数；基于空气炮冲击试验装置，分别采用直径30 mm冰球（模拟冰雹）和直径24.5 mm铝球（模拟砾石）作为冲击物，对3 mm厚玻璃钢板及其不同聚脲涂层厚度（2.5、3.0、4.5、5.0 mm）的涂覆板进行了冲击试验；采用高速摄影记录冲击过程，用以分析冲击变形序列、损伤演化规律及失效模式；运用扫描电子显微镜对严重损伤试样进行微观形貌表征，揭示了其损伤机理。研究结果表明：聚脲材料呈现高延展性特征（断裂应变为2.35）,玻璃钢表现出高强度特性（抗拉强度为141.4 MPa）;对于3 mm厚玻璃钢板，冰球冲击轻微损伤临界速度为145.3 m·s^-1,涂覆2.5 mm聚脲后临界速度提升至162.6 m·s^-1以上，至少提升11.9%;铝球冲击时，未涂覆玻璃钢板的轻微损伤和严重损伤临界速度分别为73.2、88.8 m·s^-1,涂覆4.5 mm聚脲后分别提升至88.7、119.2 m·s^-1,提升幅度达21.3%和34.4%;聚脲涂层厚度从2.5 mm增加到4.5 mm时，铝球回弹速度从13.15 m·s^-1降至11.92 m·s^-1,铝球穿透后残余速度从21.1 m·s^-1降至16.9 m·s^-1;扫描电镜分析显示，聚脲涂层能有效保持损伤区域玻璃纤维的结构完整性；涂层厚度增加至3 mm后，轻微损伤临界速度提升效应趋于饱和，但严重损伤临界速度仍可继续提高。研究成果为高速列车轻量化结构抗冲击设计提供了涂层厚度优化依据。更多还原

【Abstract】 In response to the demand for improving the impact resistance performance of glass fiber reinforced plastic（GFRP） shell structures of high-speed trains against foreign object impacts, the mechanical characteristics and impact damage mechanisms of polyurea-reinforced GFRP composites were researched. The mechanical performance parameters of polyurea and GFRP materials were determined through quasi-static tensile tests. Based on an air cannon impact test apparatus, impact tests were performed on 3 mm-thick GFRP plates and GFRP plates coated with different polyurea layers of varying thicknesses（2.5, 3.0, 4.5, and 5.0 mm）, using ice balls with a diameter of 30 mm（simulating hail） and aluminum balls with a diameter of 24.5 mm（simulating gravel） as impactors. During the test process, high-speed photography was employed to record the impact process. The impact deformation sequences, damage evolution patterns, and failure modes were analyzed. Scanning electron microscopy was utilized to characterize the microscopic morphology of severely damaged specimens to reveal their damage mechanisms. Research results indicate that polyurea material exhibits high ductility（fracture strain of 2.35）, while GFRP demonstrates high strength properties（tensile strength of 141.4 MPa）. For 3 mm-thick GFRP plates, the critical velocity for slight damage under ice ball impact is 145.3 m·s^-1, which is increased to above 162.6 m·s^-1 after coating with 2.5 mm polyurea, representing an improvement of at least 11.9%. Under aluminum ball impact, the critical velocities for slight damage and severe damage of uncoated GFRP plates are 73.2 m·s^-1 and 88.8 m·s^-1, respectively, which are increased to 88.7 m·s^-1 and 119.2 m·s^-1 after coating with 4.5 mm polyurea, representing improvements of 21.3% and 34.4%. When the polyurea coating thickness is increased from 2.5 mm to 4.5 mm, the aluminum ball rebound velocity is reduced from 13.15 m·s^-1 to 11.92 m·s^-1, and the residual velocity after aluminum ball penetration is decreased from 21.1 m·s^-1 to 16.9 m·s^-1. Scanning electron microscopy analysis reveals that the polyurea coating effectively maintains the structural integrity of glass fibers in the damage zone. When the coating thickness increases to 3 mm, the improvement in critical velocity for slight damage tends toward a plateau, but the critical velocity for severe damage can still be further improved. The findings provide a basis for optimizing coating thickness in the impact-resistant design of lightweight structures for high-speed trains.更多还原