高速飞行器翼面结构热振动试验的TARMA模型方法

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 on wing structure of high-speed flight vehicle using TARMA model method

It is important to investigate the thermal modal test of wing structure in the design and securely flight of the modern high-speed flight vehicle.The mathematical model of modal parameters identification of time-varying thermal structure, which is validated in a numerical example, is founded by time-dependent auto regression moving average (TARMA) model method.The wing structure thermal modal test system is designed by combining the ground vibration test system with the transient thermal environment simulation system.The vibration displacement of test structure is measured under random excitation signal.The change of the first four modal frequencies with heating time identified by TARMA model, that is founded by vibration displacement and shaking force measured by thermal modal test system, are well agreed with the results of numerical computation, and the error between them is less than 5%.In addition, the identification results under uniform temperature distribution thermal structure are well agreed with the results of the numerical computation, too.The reason of modal frequencies of time varying thermal structure changing with the heating time is discovered, by comparing the identification results under transient temperature field with those under uniform temperature field.The modal frequencies are influenced by structure material degraded and uniform thermal stress in structure together.