Optimization design of pipeline layout is an important means to reduce the vibration stress of engine pipeline. The multi-objective optimization design process and method for the layout parameters of the irregular pipeline were proposed. Based on the U-shaped pipeline with curved surface of engine case

a parameterized modeling method of an irregular pipeline with complex layout was established. The sensitivities of layout parameters to the dangerous natural frequencies and multi-point excitation response of the pipeline

such as the resonance frequencies

the maximum displacement and stress amplitude under multi-point excitation

were analyzed. In view of the constraints of multi-frequency and vibration responses

the method of multi-objective genetic algorithm was adopted to realize the optimal design of layout parameters of irregular pipeline. The results showed that the optimization of layouts was effective

two forbidden bands of dangerous natural frequencies were staggered. Under the same excitation

the maximum displacement amplitude of pipeline structure decreased about 35%

and the maximum stress amplitude decreased nearly 50%. It can provide a reference for the vibration controlling and dynamic forward design system of engine pipeline.