Study of Multiple-Site Damage of Aircraft Structures Based on Stochastic Fatigue Crack Growth Models

• Main Authors: Po-Yu Su, 蘇柏瑜
• Other Authors: 吳文方
• Format: Others
• Language: zh-TW
• Published: 2010
• Online Access: http://ndltd.ncl.edu.tw/handle/41677455099330736076

碩士 === 臺灣大學 === 機械工程學研究所 === 98 === Aviation safety is a very important research topic and has been studied extensively. Widespread fatigue cracks on the skin of an airplane affect aviation safety significantly and deserve to be investigated from various aspects. Widespread fatigue cracks can be considered a multiple-site damage (MSD) problem. In the present thesis, MSD on aircraft skin is studied by considering three simplified configurations. Since there is uncertainty in 2024-T351 Al alloy single-crack fatigue growth test, a randonmized Paris-Erdogan law and Yang and Manning’s law are employed respectively to describe the crack growth behavior as well as its uncertainty. The stress intensity factor range in Paris-Erdogan law for single crack condition is modified appropriately for MSD conditions. The effect of interaction between cracks is emphasized and investigated in detail, and the analysis based on Yang and Manning’s law is considered conditions without interaction. It is found that the decrease of fatigue life can be as large as 21% when considering interaction effect. It is also found that fatigue life is influenced very much by the initial crack length as well as multiple crack .