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高速飞行器翼面结构的热振动试验研究对这类飞行器的设计和安全飞行具有重要的意义。采用时变自回归滑动平均(TARMA)模型方法建立了受热时变结构系统模态频率辨识的数学模型,并用一个数值算例进行了验证。将地面振动测试系统与瞬态热环境模拟系统相结合,设计了翼面结构热振动试验系统并模拟结构的瞬态温度场,同时对纯随机激振力激励下受热时变结构系统的振动位移信号进行测量,并用TARMA模型对时变固有频率进行了辨识,获得了前4阶固有频率随加热时间的变化规律,并将辨识结果与数值计算结果进行了比较,两者误差在5%以内。另外,在稳态均匀热环境下辨识得到的结构系统固有频率变化与数值计算结果也吻合得很好。通过将均匀温度场与瞬态温度场下的结果进行对比分析,指出了瞬态热环境下时变结构的固有频率随加热时间变化的趋势主要由结构材料属性的退化和结构内部不均匀热应力的影响共同决定。
Thermal vibration test research of high-speed aircraft airfoil has important significance for the design and safe flight of this kind of aircraft. The time-varying autoregressive moving average (TARMA) model method is used to establish the mathematical model of the modal frequency identification of the heated time-varying structural system, and a numerical example is used to verify the model. Combining the ground vibration test system and the transient thermal environment simulation system, the thermal vibration test system of the airfoil structure is designed and the transient temperature field of the structure is simulated. At the same time, the vibration displacement of the heated and time-varying structural system under the excitation of purely random excitation force The natural frequency of time varying was identified by TARMA model. The variation of natural frequencies of the first 4 orders with the heating time was obtained. The results of the identification and numerical results were compared, and the errors between them were within 5%. In addition, the change of the natural frequency of the structural system identified in the steady-state uniform thermal environment is in good agreement with the numerical calculation. By comparing the results of uniform temperature field and transient temperature field, it is pointed out that the tendency of the natural frequency of the time-varying structure changing with the heating time under the transient thermal environment is mainly attributed to the degradation of the structural material properties and the uneven thermal stress inside the structure The impact of common decisions.