结构修理对民机机身耐撞性的影响

Influence of structural repairs on crashworthiness of civil aircraft fuselage

为研究结构修理对民机机身耐撞性的影响,以典型含损伤民机金属机身结构为对象,通过机身段结构的坠撞实验与仿真分析,对其修理后机身结构耐撞性进行了分析,进一步基于经实验验证的仿真分析模型研究了不同修理位置和修理面积对机身结构耐撞性的影响规律。结果表明:建立的含修理机身结构坠撞动力学模型分析结果与实验一致性较好,变形模式一致,坠撞载荷峰值误差为2.4%,机身横梁标记点最大位移误差为9.3%,机身横梁标记点速度降为零的时间误差为13.2%;蒙皮修理和机身框修理均对结构的变形模式有一定影响;蒙皮和机身框对称修理对坠撞中后期载荷有显著影响;蒙皮修理对机身结构吸能影响显著,机身框修理对机身结构吸能影响较小;对于进行过大面积修理的飞机,应对机体结构耐撞性进行评估。

To study the influence of structural repairs on the crashworthiness of civil aircraft fuselage,a typical dam⁃aged civil aircraft metal fuselage structure was taken as the research object in this paper.The fuselage crashworthi⁃ness after repair was analyzed through both drop test and simulation analysis.Furthermore,based on the verified simulation model,the effects of different repair positions and repair areas on the crashworthiness of fuselage structure were studied.The results show that the analysis results of the established crash dynamic model are in good agree⁃ment with the test results,and that the deformation modes are consistent.The peak crash load error is 2.4%;the maximum displacement error of the mark on the beam is 9.3%;the time error when the velocity of the mark on the beam drops to zero is 13.2%.Both the skin and frame repairs can influence the deformation mode of the structure.The symmetrical repairs on the skin and frame have significant influences on the load in the middle and late stages of the crash.Repairs on the skin have significant influences on the energy absorption of fuselage structure,while repairs on the frame have little effect on the energy absorption.Crashworthiness of the fuselage structure should be evaluated for the aircraft repaired in a large area.