【作者】 吴富强；

【导师】 姚卫星；

【作者基本信息】 南京航空航天大学 ， 飞行器设计， 2005， 硕士

【摘要】 随着科技发展,纤维增强树脂基复合材料(Fiber Reinforced Plastic,简称 FRP)因其良好的力学性能已被广泛应用于航空,航天,船舶,交通等领域。在工程应用中,疲劳破坏是一个重要的失效形式,急待解决。为满足工程需要,众多研究人员对 FRP 的疲劳问题进行深入研究,提出各类预测模型,但理论值与实际情况仍存在较大误差,因此有必要对 FRP 的疲劳问题作进一步研究。 本文对几类研究 FRP 疲劳问题的常见模型作简要回顾后,从累积损伤角度提出一个强度降累积损伤模型。该模型定量描述了 FRP 层合板静强度,纤维强度,铺设方式和外载水平等因素对 FRP 疲劳行为的影响,并能预测变幅载荷下 FRP 层合板的疲劳寿命和剩余强度。经试验验证,该模型较好地反映了 FRP 疲劳损伤扩展规律。 在研究 FRP 疲劳机理后,本文还提出一个 S-N 曲线模型,并把它与被广泛采用的其他模型进行比较,比较结果显示本文所提出的模型优于它们。另外本文 S-N 曲线模型不仅很好地描述 FRP 损伤扩展机理,而且所需材料参数少且容易得到,有利于工程应用。更多还原

【Abstract】 Fiber Reinforced Plastic(FRP) has been widely used in aircraft, spacecraft, watercraft and transportation because of its excellent mechanical characteristics. Fatigue strength is one of the important mechanical properties for engineering materials. The fatigue behavior of FRP has been investigated by many researchers in the world in the past decades. Many models to predict fatigue life and to describe the other characteristics of FRP have been presented, but there are still many problems left to be further investigated for the engineering application. The widely used models to explain fatigue characteristic of FRP are reviewed firstly in this thesis, and then a fatigue cumulative rule based on strength degradation damage model was presented, in which the parameters affecting fatigue strength, such as ultimate strengths of fiber and laminates, fibre orientations, loading, are included. The presented model can predict fatigue life and residual strength of composite laminates under constant and varied amplitude loading. It was been verified that the presented model rationally explains the damage development law of FRP by cited experimentation date. A S-N curve model to describe the connection between load and fatigue life of FRP was set up in the present paper based on the fatigue mechanism of FRP. Several sets of experimentation date were employed to verify the proposed S-N curve model, and the results show that comparing to the other commonly used S-N curve model, the presented S-N curve model is superior to other models in the regression of experimental data. Moreover, the presented S-N curve model needs fewer material constants and they are obtained more easily.更多还原