Dynamics And Vibration Fatigue Analysis Of Liquid Sloshing In An Aircraft Fuel Tank

Liquid Sloshing problems exist in the field of aerospace,ship and pavement transportation.For the aircraft,the liquid in the aircraft fuel tank will slosh when taking off,landing or changing flight attitude;the liquid will also vibrate because of the air turbulence, the engine imbalance rotor etc.This phenomenon is called aircraft fuel tank sloshing.On the one hand,the centre of gravity(CG)may be changed due to the fuel CG transition,and the aircraft stability will also be influenced;on the other hand,cyclic impact load will result in the fatigue failure and decrease the service life of the fuel tank.At present,most of the reserach on fuel tank sloshing of aircraft depends on high cost tests at home and abroad. Recently,more and more finite element analysis method is applied to solve the problem of fuel tank sloshing thanks to the rapid development of computer technology. Numerical reserch on fuel tank sloshing can not only reduce the research costs but also has academic value and practical significance.This paper aims to describe the continuous and incompressible fluid with free surface in a tank and finite analysis theory using mathmatical method first, then, build the fluid-structure interaction model by MSC/Dytran while analyse the influence factor of fuel tank sloshing. After that,the structure dynamics was analysed by Msc/Nastran. According to the stress-time curves,the life of the most danger node will be calculated. Beause of the complex traditional protocol specific implementation,At last, present a new test method based on vibration fatigue life by Msc/Fatigue, and ensure the magnitude of the excitation of a certain shape,this method improves the fessibility and convenience of testing.