重复使用飞行器分布式连接结构振动及疲劳研究OA北大核心CSTPCD

Accurate calculation of the vibration characteristics and fatigue life of the distributed connection structures between reusable spacecraft and engines was crucial for ensuring the safe opera-tions of aerospace transportation systems.Focusing on the distributed connection structures,the fea-sibility of experimental validation for finite element simulation methods was demonstrated.The vibra-tion characteristics of the distributed connection structures were explored in both of the time and fre-quency domains,and the fatigue lives of the structures were calculated under different operating con-ditions.The findings reveal a commendable concordance between the finite element results of the hys-teresis curve for the connection structures and experimental observations.Under cyclic loading at dif-ferent excitation frequencies,the connection bolts manifest stress increments or decrements,indica-tive of fatigue effects.The distributed connection structures elicit significantly heightened responses at the 1st and 5th natural frequencies.Decreasing the excitation magnitude substantially augments the fa-tigue lives of the connection structures,and an escalation in bolt pre-tightening forces is found to en-hance fatigue lives as well.However,an increase in excitation frequency only marginally diminishes the operational lifespans,while the cyclic lifespans persist within the same order of magnitude.Fur-thermore,following the introduction to thermal and creep effects,the distributed connection struc-tures may withstand a maximum of only five thermal cycling loads.