As an important channel for energy transmission in aero-engines

the fatigue strength and reliability of aviation high-pressure pipeline system have a direct impact on the flight performance and service life of aircraft. Based on the three shear unified strength criterion

a bilinear dynamic strengthening model considering material strain hardening and Bauschinger effect was adopted to establish a finite element analysis model for the autofrettaging treatment of typical aviation high-pressure pipelines. Analyze the distribution pattern of residual compressive stress after autofrettaging treatment of stainless steel

aluminum alloy

and titanium alloy pipelines; Conduct simulation analysis and experimental verification on the fatigue life of stainless steel pipelines; Calculate the mechanical response results of the internal to external diameter ratio and bending angle of aviation high-pressure pipelines to autofrettaging treatment. The results show that compared with other materials

titanium alloy pipelines with autofrettaging treatment will achieve a better residual compressive stress state; At the same time

analyzed the residual compressive stress state after bending treatment and under working load

and based on the variation law of residual compressive stress with diameter ratio and bending angle

the range of diameter ratio and bending angle for obtaining the best self strengthening treatment effect of the pipeline was determined. The stress state of the bend under working state was analyzed

and the method of selecting autofrettaging pressure when there are multiple bending angles on the pipeline was analyzed

providing a theoretical basis for the application of autofrettage in aviation high-pressure pipelines.