【作者】 王冲；

【导师】 鲁统利； 蒲大宇；

【作者基本信息】 上海交通大学 ， 机械工程， 2012， 硕士

【摘要】 扩展有限元法是一种新的处理裂纹扩展问题的方法，其在继承传统有限法优点的同时，克服了网格划分繁琐和裂纹扩展后网格重新划分的缺点。本文应用扩展有限元法进行了飞机典型蒙皮连接钉孔裂纹扩展过程的数值模拟，研究了诸如埋头划窝，钉孔间距等钉孔细节对裂纹扩展寿命的影响。论文主要内容总结如下：1.系统阐述了飞机结构损伤容限分析基本思想和实施过程。对比了几种应力强度因子的计算方法，提出扩展有限元法在保证精度前提下适用范围最广，计算效率最高。2.针对ABAQUS无法自动实现裂纹扩展计算的缺陷，利用Excel宏程序编写了ABAQUS外部接口程序，实现了裂纹自动扩展功能。通过典型算例分析,并与行业标准软件NASGRO分析结果进行比较，验证了接口程序及扩展有限元法的正确性和实用性。3.应用该接口程序对飞机典型蒙皮连接钉孔结构进行裂纹扩展分析。分析结果表明钉孔埋头划窝、过小的钉孔间距等细节会明显降低钉孔裂纹扩展寿命。通过大量的计算数据绘制了相关图表，量化了钉孔细节对裂纹扩展寿命的影响程度。本文研究工作对飞机类似结构的裂纹扩展寿命分析和损伤容限评估具有实际工程应用价值和参考意义。更多还原

【Abstract】 Extended finite element method is a new effective method for modeling the crackgrowth process, which inherits mature theories and techniques of traditional finiteelement method. Extended finite element method overcomes disadvantages of fractureanalysis of traditional method such as too refined mesh around the crack tip andre-meshing when crack propagation. In this dissertation, extended finite elementmethod is used to simulate the crack growth process of aircraft skin connection. Theinfluence of structure details such as countersink and rivet holes pitch to the crackgrowth life is studied. The main contents are as follows:1. The basic theories and implemental process of damage tolerance analysis arereviewed. Several methods of calculating the stress intensity factor are studied. It isproved that the extended finite element method is the most efficient method.2. Since ABAQUS cannot perform the crack growth automatically, an Excelmacro interface program is developed. By comparing the result analyzed by NASGRO,the interface program is validated to be correct and reliable.3. The crack growth analysis of rivet hole of typical aircraft skin connection isachieved by using the interface program. The analysis results show that the structuredetails such as countersink and rivet holes pitch reduce the crack growth lifesignificantly. Through a large number of calculations, charts and figures areformulated to quantify the influence of structure detail.The studies in this dissertation could be utilized in engineering application ofcrack growth life prediction and damage tolerance analysis of airplane structure.更多还原