Reliability analysis on resonance fatigue life of fuel piping system

Abstract

The fuel piping system is vital for fuel transportation and the corresponding reliability is the necessary prerequisite for the normal operation of aero engines. Given the broad frequency range of external excitations, structural resonance of the fuel piping system is unavoidable, often leading to structural fatigue failure. This paper aims to elucidate the mechanisms of fatigue failure and establish a framework for probabilistic fatigue life assessment of the fuel piping system under prolonged resonance excitation. Firstly, sweep frequency and resonance fatigue tests of fuel piping system are conducted to determine the resonance frequencies, resonance strain responses and corresponding fatigue lives. The accuracy and effectiveness of the finite element model, as well as previously established fatigue life models for the components of the piping system, are then validated through deterministic modal and implicit dynamic analysis. Subsequently, a distributed collaborative (DC) probabilistic analysis method, based on the cross-validation (CV)-Voronoi sequential sampling approach for Kriging surrogate model (DC-CV-Voronoi-KSM), is proposed for reliability analysis of resonance fatigue. The novelty of this method lies in the use of the CV-Voronoi method as a sequential sampling approach for constructing a global Kriging surrogate model, with the DC strategy employed to reduce the complexity of Kriging model. Finally, the DC-CV-Voronoi-KSM method is adopted to conduct reliability analysis on the resonance fatigue of the fuel piping system, yielding the distribution of resonance responses and the load cycle-failure probability curve, which provides significant guidance for the application of fuel piping systems on aero engines.