汽车CFRP结构在实际服役条件下的温度-湿度-载荷耦合老化失效预测方法

CFRP（碳纤维增强树脂基复合材料）在汽车上的应用是实现轻量化的有效途径之一。CFRP在温度、湿度、载荷耦合作用下会发生老化，影响其失效模式和承载能力，目前还没有针对CFRP结构在汽车实际服役条件下的老化失效预测方法。.本项目选择温度、湿度、载荷三种主要老化因素，根据汽车实际服役特点构建单因素、双因素及多因素耦合加速老化环境，研究CFRP力学性能变化和化学性能变化的定量相关关系，揭示多因素耦合作用下的老化失效机理；研究加速老化条件和实际服役条件下温度-湿度-载荷耦合老化规律之间的关系，根据力学性能和化学性能测试，提出汽车CFRP结构在实际服役条件下的老化因子预测方法。研究汽车CFRP结构在实际服役老化后的本构关系和失效准则，基于损伤力学模型，建立CFRP的老化失效仿真分析模型，结合实车试验改进并验证老化失效预测方法。本项目能够为复合材料的老化失效预测提供理论支持，促进复合材料在汽车上的应用

The use of CFRP (Carbon Fiber Reinforced Plastic) in automobiles is one of the most effective way to achieve lightweight. However, CFRP structures undergo aging when subjected to coupling effect of temperature, humidity and loads in service and the aging has obvious effect on the carrying capacity and failure modes. Currently there's no prediction method of aging failure for automobiles in actual service..In this project, three aging factors of temperature, humidity and loads are selected, and single factor, two-factor and multi-factor accelerated aging environment are built according to the typical aging environment of automobiles in service. The quantitative relationship of mechanical and chemical properties of CFRP after aging is investigated to reveal the aging mechanism of CFRP under the multi-factor coupling effect. The aging rules of accelerated aging and actual service subjected to coupling effects of temperature, humidity and loads were studied, which are used to propose the predicting method of aging level of CFRP applied to automobiles in actual service. The constitutive equation and failure criterion of CFRP after aging of automobiles in actual service are derived, and then the failure prediction model of CFRP is built based on the damage mechanics model. The real car test is conducted to improve and verify the prediction method of aging failure. This project provides theoretical support for aging failure prediction and promote the application of composite materials in automobiles.