【作者】 罗成利；

【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】 有机玻璃材料由于具有较好的透光性和足够的结构强度而广泛应用于飞机座舱盖、风挡等结构中。有机玻璃结构的疲劳性能是一个重要指标,飞机座舱盖的疲劳定寿工作是飞机结构疲劳定寿的重要内容之一。 本文首先回顾了有机玻璃材料的疲劳行为,综述了材料的蠕变模型及与松弛模型之间的关系,介绍了有机玻璃材料疲劳寿命估算方法,设计了蠕变试验及试验装置,完成了 YB-3 有机玻璃试件的单轴拉伸蠕变试验与疲劳试验,给出了试验结果,分析了试验条件对结果产生的影响。基于损伤力学,提出了一个适合于 YB-3 有机玻璃材料的蠕变损伤的修正模型,结合蠕变试验结果,成功描述了蠕变行为,预测了蠕变断裂时间;并结合疲劳试验结果,分析得到蠕变/疲劳损伤演化模型,模型的预测结果与试验结果吻合较好。 本文的算例表明,所提出的修正模型能够成功分离出试验结果中的蠕变损伤和纯疲劳损伤。更多还原

【Abstract】 Polymethyl Methacrylate(PMMA) has been widely used in the wind shield of aircraft because of its excellent transparency and strength. The fatigue behaviour of PMMA is very important for the aircraft windshield structure. The commonly used creep models, relaxation models and the relationships between creep and relaxation of PMMA are reviewed in the present thesis. The prediction approaches of fatigue life of PMMA structures are discussed. A simple test device for creep experiment was designed. Axial creep experiment and fatigue experiment of YB-3 PMMA had been carried out. Based on continuum damage mechanics, a modified model to describe the creep damage of YB-3 is developed. Creep experiment data proved that this model can explain creep behavior better and predict creep fracture time of YB-3 more accurately. A creep and fatigue damage model has been presented to explain fatigue test results. There is excellent consistency between the predicted and experiment data.更多还原