汽车工程 ›› 2025, Vol. 47 ›› Issue (12): 2450-2458.doi: 10.19562/j.chinasae.qcgc.2025.12.017

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聚脲涂覆铝制纵梁抗冲击性能的试验与数值分析

汪辉1(),赵杨2,周锦波1,金海峰1,曹家健2,刘超2   

  1. 1.浙江极氪汽车研究开发有限公司,宁波 315800
    2.清华大学苏州汽车研究院(相城),苏州 215000
  • 收稿日期:2025-03-21 修回日期:2025-04-30 出版日期:2025-12-25 发布日期:2025-12-19
  • 通讯作者: 汪辉 E-mail:Hui.Wang37@zeekrlife.com

Experimental and Numerical Analysis of Impact Resistance of Polyurea-Coated Aluminum Longitudinal Beams

Hui Wang1(),Yang Zhao2,Jinbo Zhou1,Haifeng Jin1,Jiajian Cao2,Chao Liu2   

  1. 1.Zhejiang ZEEKR Automobile Research & Development Co. ,Ltd. ,Ningbo 315800
    2.Suzhou Automobile Research Institute of Tsinghua University (Xiangcheng),Suzhou 215000
  • Received:2025-03-21 Revised:2025-04-30 Online:2025-12-25 Published:2025-12-19
  • Contact: Hui Wang E-mail:Hui.Wang37@zeekrlife.com

摘要:

为兼顾乘用车轻量化设计与碰撞安全性能提升的需求,本研究以直接承载纵向载荷的一体压铸铝制纵梁为研究对象,系统探究聚脲涂层厚度(0 - 7 mm)与界面强度(6 - 14 MPa)对其抗冲击性能的协同强化机制。通过开展材料层级的聚脲静动态拉伸试验、聚脲-铝合金界面双悬臂梁(DCB)试验,以及零部件层级的纵梁静动态压溃等试验,结合基于LS-DYNA平台构建的三维有限元模型,实现了涂层参数的多维度验证与优化分析。研究结果表明,聚脲材料具有显著的应变率强化特性;当涂层厚度为6 mm时,纵梁冲击峰值载荷可提升16.53%;然而参数优化显示,3 mm厚度区间能实现最优能量吸收效率。界面强度在12 MPa左右时能量传递效率最高,强度不足则易引发界面剥离失效。仿真与试验结果对比显示,冲击峰值误差控制在10%以内,且失效模式高度一致。综上所述,通过合理匹配聚脲涂层厚度与界面强度,可有效提升纵梁的承载能力、吸能效率及结构完整性(如减少碎片飞溅),同时改善其冲击过程中的变形模式,抑制局部脆性断裂与失稳屈曲,从而为汽车轻量化与安全性协同设计提供理论依据与工程实践支撑。

关键词: 铸铝纵梁, 聚脲涂层, 有限元分析, 冲击性能

Abstract:

To meet the dual demand of lightweight design and crash safety performance improvement in passenger vehicles, in this study the synergistic reinforcement mechanism of polyurea coating thickness (0-7 mm) and interface strength (6 - 14 MPa) on the impact resistance of a one-piece die-cast aluminum rail that directly carries longitudinal loads is investigated. Through material-level static and dynamic tensile tests on polyurea, interfacial double cantilever beam (DCB) tests, and component-level quasi-static and dynamic crush tests on the rails, combined with a three-dimensional finite element model built on the LS-DYNA platform, multi-dimensional validation and parametric analysis of the coating are conducted. The results show that polyurea exhibits significant strain rate hardening behavior. When the coating thickness is 6 mm, the impact peak load of the rail can be increased by 16.53%. However, parameter analysis reveals that a thickness of approximately 3 mm achieves optimal energy absorption efficiency. The interface strength of around 12 MPa provides the best energy transfer efficiency, while insufficient strength may lead to interfacial delamination. The comparison between simulation and experimental results shows that the error in peak impact force is controlled within 10%, with highly consistent failure modes observed. In conclusion, by appropriately matching the polyurea coating thickness and interface strength, the load-bearing capacity, energy absorption efficiency, and structural integrity (e.g., reduced fragment scattering) of the rail can be effectively enhanced, while improving deformation behavior during impact and suppressing local brittle fracture and buckling instability, thereby providing both theoretical support and engineering guidance for the coordinated design of automotive lightweight and safety.

Key words: cast aluminum longitudinal beam, polyurea coatings, finite element analysis, impact property