OPTIMIZATION DESIGN OF AERO-ENGINE PIPELINE VIBRATION BASED ON GENETIC ALGORITHMS

摘要

The piping system of aero-engine is a complicated structure system, at the same time these pipes are the multi-fault components on engine. The work conditions of the piping system are very inclement. The failures such as fracture and oil leak of these pipes are often happened, and vibration is the most important reason that leads to these phenomena. The aim of the optimization design of the piping system is to avoid resonance or to obtain the lowest stress level using the optimization theories for the sake of the most optimal supporting locations and stiffness of the clips. In this paper, a universal and effective optimization program for piping system of aero-engine is presented, which used the genetic algorithm (GA) according to the structure and vibration characteristics of the pipes and based on the finite element method. In order to ensure it correct and universal, this program is carried out on the FEM software NASTRAN. A full size pipe is designed using frequency, amplitude and curvature as the optimization objective functions and the optimization results are acquired respectively. The calculated results and analysis show that this design method can achieve optimization solutions effectively. These solutions are testified to satisfying the stress distribution of the engineering requirement. Frequency adjustment is adopted firstly when the supporting locations and numbers of the clips can be fulfilled because its calculation process is quick and the stress level is generally lower in the running condition. The new objective function-curvature presented in this paper is found better than amplitude in the piping system design. In the end, some proposes are suggested for the vibration optimization design of the piping system.