For analysis of the stability reliability of spatial aeroengine pipe system

a probabilistic reliability method based on finite element method (FEM) and Monte Carlo method (MCM) was proposed. A fluidstructure coupling model of the pipe system was established with FEM. A limit state function of stability reliability was presented on the basis of analysis of natural frequency. The stability reliability was calculated using MCM. The analysis results of typical pipe system showed that: for a given mean flow velocity

as the variation of flow velocity increased

the divergence instability probability may increase or decrease; for a given variation of flow velocity

the probability density function of limit state function changed to the mixed probability density function from the continuous probability density function as the mean value of flow velocity increased. The result is valuable for stability reliability design and analysis of pipe system conveying fluid.