Influential Factors in Safety Design of Aircraft Pneumatic Duct System

The reliability and safety of the pneumatic ducts are essential for flight safety.A beam element model of the duct system is developed and the factors that impact the stress performance of the duct system are investigated,such as stress check standards,flight acceleration,internal temperature and internal pressure.The results show that the stress synthetic method as the stress check standard can obtain the more safety design results.The maximum stress of straight pipe is affected significantly by the acceleration in a plane perpendicular to straight pipe,while the maximum stress of bend pipe is greatly affected by the acceleration in the direction perpendicular to plane of the bend pipe.Meanwhile,internal pressure has little effect on the maximum stress of bend pipe and straight pipe.Temperature has little effect on the maximum stress of bend pipe while has a big impact on the maximum stress of straight pipe.