某歼击机机身主承力框的耐久性分析

DURABILITY ANALYSIS FOR A MAIN BULKHEAD SUBJECTED TO LOAD ON THE BODY OF AN AIRCRAFT

对已服役的某歼击机最重要的关键件——机身主承力框进行了耐久性分析,通过修理前后的原始疲劳质量评估与经济寿命预测,给出了合理的修理大纲,使该构件的经济寿命达到用户提出的使用寿命要求。

In this paper, the durability analysis for the main bulkhead subjected to load on the body is carried out, that is the most important key part of a aircraft. The object of durability analysis is evaluation damage degree and economic life of the main bulkhead for fleet of airframes. The structural details are the fastener holes on the cross beams of the main bulkheads. The durability analysis method takes probabilistic fracture mechanics approach (PFMA). Evaluation of the initial fatigue quality(IFQ)and prediction of the economic life for non-repaired bulkheads show that selecting 1000 fly hours as first repairment time is rational. The evaluation of IFQ and prediction of economic life for repaired bulkhead show that two limes of repairment is necessary for satisfying the service life requirement. On the basis of durability analysis, a rational repairment program is given.