碳纤维织物增强复合材料中空结构的低速冲击损伤机理研究

Lightweight is one of main techniques for the industrialization of electric vehicles. The carbon textile fiber reinforced plastic material(CFRP) can achieve the lightweight of electric vehicle effectively, however the investigations on the impact mechanism and safe performance of structures made of CFRP are not sufficient, and these limit the application of them. Firstly, the damage analysis and residual strength of rectangular tubes and T-shape tubes made of CFRP under low velocity impact tests are investigated; Secondly, a three-dimension refined simulation model is developed to predict the damage behavior of fiber, resin and interfaces, which is compared with experimental results; Thirdly, the multiscale modeling and damage analysis are applied on complex electric vehicle structure in order to improve the accuracy and efficiency of the failure degree prediction inside the impact zone; Finally, the relationship between damage evolution and structure parameters is obtained combining structural design tests and simulation analysis. The investigation is useful for expanding the damage mechanism of hollow structure made of CFPR under low velocity impact, also developing an effective multiscale damage analysis method for complex structure, which will play a key role in practical lightweight structural design.

轻量化是电动汽车产业化的关键技术之一，碳纤维织物增强复合材料能有效实现电动汽车结构轻量化，然而对其冲击损伤机理和碰撞安全性认识尚不充分，影响其推广应用。项目拟通过试验研究，掌握碳纤维织物增强复合材料二通和三通基础结构的冲击性能和剩余强度规律；通过细观力学有限元分析，建立能够综合考虑织物材料纤维、树脂和界面破坏的三维精细化损伤演化模型；采用有限元方法结合二次开发，开展复杂车身结构的多尺度一致性损伤演化分析方法研究，实现整体结构破坏区域损伤程度的高效预测；结合结构设计试验和仿真计算，揭示结构参数对损伤演化的影响规律。本研究成果对完善增强复合材料结构（以往多为层合板）的损伤机理，建全复杂结构损伤分析方法，指导轻量化结构设计具有较高的学术价值和显著的实践意义。

轻量化是电动汽车产业化的关键技术之一，碳纤维增强复合材料能有效实现电动汽车结构轻量化，然而对其冲击损伤机理和碰撞安全性能认识尚不充分，因此本项目对碳纤维复合材料结构的低速冲击损伤机理和性能进行了深入研究。首先通过实验研究，掌握了层板的低速冲击性能和剩余性能、粘接层板的裂纹扩展和耐撞性能、碳纤维复合材料管件的破坏机理和剩余性能规律。其次对层板开展了细观力学有限元分析，结合二次开发建立了能够综合考虑织物材料界面破坏和层间破坏的三维精细化损伤演化模型，获得了与实验相吻合的破坏模型和力-位移曲线，揭示了内部复杂的损伤机理。最后开展了复杂车身结构的力学仿真，建立了车身B柱的多尺度一致性损伤演化三维模型，成功预测了承载区域的渐近式破坏过程；开展了车身整体结构的多尺度力学仿真，评价了车身结构的安全。本项目完善了增强复合材料结构的损伤机理，建全了复合材料结构的力学计算方法，指导了轻量化电动汽车结构的开发。