碳纤维/格栅增强蜂窝夹芯结构抗冲击性能试验与车体顶棚仿真

IMPACT RESISTANCE TEST OF CARBON FIBER/GRID REINFORCED HONEYCOMB SANDWICH STRUCTURE AND VEHICLE ROOF SIMULATION

复合材料夹芯结构在轨道车辆轻量化设计中应用广泛,传统单一铝蜂窝芯体的复合材料夹芯结构抗冲击性能较差,难以满足运用需求。在传统碳纤维/铝蜂窝夹芯结构的芯体中引入网格形格栅,形成碳纤维/格栅增强蜂窝夹芯结构,在格栅交点处、单肋板中心处和格栅中心处3种典型位置对其分别进行落锤冲击试验与冲击后压缩试验。并将碳纤维/格栅增强蜂窝夹芯结构应用于车体顶棚结构,在落石冲击工况下建立了3种不同材料的车体顶棚仿真模型,分析其比峰值载荷和比刚度等力学性能。结果表明:碳纤维/格栅增强蜂窝夹芯结构相较于传统碳纤维/铝蜂窝夹芯结构,其抗冲击性能更强,冲击后压缩强度高出约34%,压缩刚度高出约52%;位于格栅交点处与单肋板中心处的接触力峰值、分层临界载荷与凹坑深度显著优于格栅中心处;与碳纤维/铝蜂窝车体顶棚相比,碳纤维/格栅增强蜂窝车体顶棚在落石冲击下的变形量减小了71.73%,比峰值载荷与比刚度分别提高了133.33%、146.72%。碳纤维/格栅增强蜂窝夹芯结构兼具轻量化与性能强的优点,适合作为大型承载结构,可以为高速列车车体结构设计提供参考。

Composite sandwich structure is widely used in lightweight design of rail vehicles.Traditional composite sandwich structure with a single aluminum honeycomb core has poor impact resistance,which is difficult to meet the application requirements.A rectangular aluminum grid structure is added into the core of the traditional carbon fiber/aluminum honeycomb sandwich structure to form the carbon fiber/grid reinforced honeycomb sandwich structure,and the drop hammer impact test and post-impact compression test are carried out at three typical positions,the intersection of the grid,the center of the single rib plate and the center of the grid.The carbon fiber/grid reinforced honeycomb sandwich structure is applied to vehicle roof.The simulation models of vehicle roofs of three different materials are established under the rockfall impact condition to analyze the mechanical properties such as specific peak load and specific stiffness.The results show that the carbon fiber/grid reinforced honeycomb sandwich structure has stronger impact resistance than traditional carbon fiber/aluminum honeycomb sandwich structure,with compression of approximately 34% higher and compressive stiffness of 52% higher after impact strength;The peak contact force,delamination critical load and dent depth at the intersection of the grid and the center of the single ribbed plate are significantly better than those at the center of the grid;Compared with the carbon fiber/aluminum honeycomb vehicle roof,the deformation of the carbon fiber/grid reinforced honeycomb vehicle roof under rockfall impact is reduced by 71.73%,and the specific peak load and specific stiffness are increased by 133.33% and 146.72% respectively.The carbon fiber/grid reinforced honeycomb sandwich structure has the advantages of both lightweight and strong performance,which is suitable as large-scale bearing structure and can provide a reference for the structural design of high-speed train body.