Development and Validation of Bonded Composite Doubler Repairs for Commercial Aircraft.

Roach, D. ; Rackow, K.

Technical Information Center Oak Ridge Tennessee

关键词: Aircraft;    Composite materials;    Repair;    Damage assessment;    Tolerance;   

RP-ID  :  DE2007912655

学科分类：工程和技术（综合）

美国|英语

来源: National Technical Reports Library

【 摘 要 】

This report presents the array of engineering activities that were completed in order to make this technology available for widespread commercial aircraft use. Focused laboratory testing was conducted to compliment the field data and to address specific issues regarding damage tolerance and flaw growth in composite doubler repairs. Fatigue and strength tests were performed on a simulated wing repair using a substandard design and a flawed installation. In addition, the new Sol-Gel surface preparation technique was evaluated. Fatigue coupon tests produced Sol-Gel results that could be compared with a large performance database from conventional, riveted repairs. It was demonstrated that not only can composite doublers perform well in severe off-design conditions (low doubler stiffness and presence of defects in doubler installation) but that the Sol-Gel surface preparation technique is easier and quicker to carry out while still producing optimum bonding properties. Nondestructive inspection (NDI) methods were developed so that the potential for disbond and delamination growth could be monitored and crack growth mitigation could be quantified. The NDI methods were validated using full-scale test articles and the FedEx aircraft installations.