计及轴向力作用的柔性梁热—形耦合振动研究  

Research on thermal-deformation coupling vibration of flexible beams considering axial force

作　　者：吴磊 韩飞 邓子辰 WU Lei;HAN Fei;DENG Zichen(School of Mechanics,Civil Engineering and Architecture,Northwestern Polytechnical University,Xi’an 710129,China;School of Aeronautics,Northwestern Polytechnical University,Xi’an 710072,China)

机构地区：[1]西北工业大学力学与土木建筑学院,西安710129 [2]西北工业大学航空学院,西安710072

出　　处：《航空工程进展》2024年第6期216-223,254,共9页Advances in Aeronautical Science and Engineering

基　　金：国家自然科学基金(12232015,12372023)。

摘　　要：飞行器中的梁—索组合式结构在服役期间由于太阳热辐射引起的交变热流,会使结构产生热致变形及振动。杆件的变形又会进一步影响热流的大小和分布,是一类典型的力—形耦合系统。耦合系统的刚度、质量或载荷矩阵通常具有时变特征,通常只能通过多次求解特征方程并借助逐步积分的方法获得系统的模态及响应。如何保证求解过程的计算精度和效率是一大挑战。基于动力刚度方法与Wittrick-Williams算法,进行系统固有频率和模态的精确求解,结合精细积分法计算结构响应。结果表明:前4阶固有频率与有限元解的偏差在1‰以内,响应最大相对偏差为1%;当时变热轴力接近结构失稳临界载荷时,结构振动频率快速减小并趋于0,热致振动将出现发散现象。The beam-wire structure in aircraft can cause thermal deformation and vibration of flexible members during service due to alternating heat flux caused by solar thermal radiation.The deformation of the rod will further affect the magnitude and distribution of heat flux,making it a typical force shape coupling system.The stiffness,mass,or load matrix of a coupled system usually has time-varying characteristics,and the modal and response of the system can only be obtained by solving the characteristic equations multiple times and gradually integrating them.How to ensure the computational accuracy and efficiency of the solving process is a major challenge.Based on the dynamic stiffness method and the Wittrick Williams algorithm,the accurate solution of the system´s natural frequency and mode has been achieved.Combining with the precise integration method,the structural response is calculated.The results show that the deviation between the first fouth natural frequencies and the finite element solution is within 1‰,and the maximum relative deviation of the response is 1%.When the variable thermal axial force approaches the critical load for structural instability,the vibration frequency of the structure rapidly decreases and tends towards 0,and the thermally induced vibration will exhibit divergence.

关 键 词：梁—索结构 热致振动 时变热轴力 动力刚度法 Wittrick-Williams算法 

分 类 号：V214[航空宇航科学与技术—航空宇航推进理论与工程] V414