基于断裂力学的多部位损伤结构的剩余强度分析方法研究

老龄飞机中由于多裂纹的产生将导致结构剩余寿命大幅削减。针对如飞机机舱上布有沿纵向铆钉接头的隔板结构,文中给出一种分析多部位损伤结构剩余强度的方法。裂纹扩展模型是分析的基础,文中对两类(单参量和三参量)扩展模型进行讨论,给出裂纹在增量载荷下萌生与稳定扩展的处理方法。基于Irwin和Dugdale裂尖张开位移模型与Swift准则,给出较为完整的分析多部位损伤(multiple site damage,MSD)结构剩余强度的方法。最后,通过对飞机压力舱上的沿纵向铆钉接头的模拟计算,对文中方法进行验证。由分析结果可知,采用文中方法计算得到的剩余强度值与试验值符合得较好,该方法能较为准确有效地对复杂MSD结构的剩余强度进行分析。

STUDY ON FRACTURE MECHANICS ANALYSIS OF RESIDUAL STRENGTH OF STRUCTURE WITH MULTIPLE SITE DAMAGE

The residual life will be reduced because of multiple site damage(MSD)in ageing aircraft. For the fuselage structure with longitudinal riveted joints,a method of computing residual strength of structure with MSD was presented. Basing on two models of cracks growth,one parameter and three parameters models,the way of analyzing the stage of initiation and stable tearing was discussed in details. Irwin and Dugdale models were used to calculate crack tip opening displacement (CTOD). Swift criterion was used to ...