Nonlinear Dynamic Analysis Of Flame Tube Thin-wall Shell Structure Under Thermoacoustic Load

The high temperature acoustic fatigue of porous thin-walled structure is studied by numerical simulation and experimental verification.The response results are calculated and the fatigue life of the structure is predicted.（1）A dynamic response analysis method of thin-walled structures under combined thermal and acoustic loads is established.The fatigue life prediction model of thin-walled structure is established,and a complete and effective dynamic response calculation and fatigue life prediction method of thin-walled structure are formed.（2）The dynamic response characteristics of typical thin-walled shell structure are calculated.Aiming at the typical failure modes of structures under complex loads,a structural fatigue analysis model considering complex nonlinear dynamic response characteristics is established,and the fatigue life prediction is completed.Based on the test data,the dynamic response characteristics and fatigue life of the structure are analyzed to verify the correctness of the test and the accuracy of the simulation.（3）Based on the high temperature acoustic fatigue test of thin-walled structure,a numerical simulation model of thin-walled structure with openings is established to study the effect of openings on stress response and fatigue life time.By changing the location of holes and increasing the number of holes in the thin-walled structure,the thermoacoustic response of the porous thin-walled structure is calculated,and the dynamic response law of the porous structure and the influence on the structure are analyzed and summarized.（4）The simplified numerical simulation model of short annular flame tube is established,and the thermal modal frequency is calculated by finite element analysis method.The coupled finite element and boundary element methods are used to calculate the dynamic response characteristics of the short annular flame tube under the thermoacoustic load,and the dynamic response characteristics of the flame tube under the thermoacoustic load are obtained.In this paper,the dynamic response calculation and fatigue life prediction of thin-walled structures under thermoacoustic loads are carried out by combining numerical simulation with experimental verification.The dynamic response characteristics of thin-walled structures with openings and holes are calculated by numerical simulation.This work provides a basis for dynamic strength analysis and stability design of Aerospace Thin-walled Structures.