舵面结构热模态试验方法研究

目的探究高温对舵面结构模态试验结果的影响。方法以导弹舵面为研究对象,开展高温环境下结构模态试验方法研究。基于石英灯热辐射高温加热系统和模态测试系统搭建热模态试验测试平台,采用带水冷装置的耐高温加长激振杆实现激励的施加,设计耐高温陶瓷引伸杆进行振动信号的测试,通过有限元仿真分析与试验数据对比,验证所提热模态试验方案的可行性。结果当激振杆的正弦扫频试验在20~1000 Hz范围内,其传递函数值接近于1,说明激振杆传递性能良好。陶瓷引伸杆对试验件前四阶模态频率及振型影响较小,验证了陶瓷引伸杆设计的有效性。试验数据表明,试验件材料的刚度随着环境温度的升高逐渐降低,导致各阶模态的频率呈逐渐降低的趋势。结论高温会使舵面结构的模态参数降低,该研究为后续型号产品的热模态试验提供了的试验手段和技术支持。

Research on Thermal Modal Test Method of Rudder Structure

The purpose of this paper is to explore the influence of high temperature on the modal test results of rudder structure. With the high temperature environment, the missile rudder is studied by the approach of structural modal test. The thermal modal test platform mainly includes the heating system of quartz lamp and the modal testing system. For the excitation part, the high- temperature resistant extended exciting rod is used and equipped with water cooling device. The high-temperature resistant ceramic extension rod is designed to improve the vibration signal collection scheme. The feasibility of the thermal modal test scheme is verified by the comparison finite element analysis and test data. The test results show that the transfer function value of exciting rod is close to 1 when sinusoidal sweep frequency in the range of 20 Hz to 1000 Hz, which is very ideal for the excitation part. However, for testing system, the ceramic extension rod has a little influence on the first four-order modal frequency and the results are within acceptable limits. In the end, we compared the influence of rudder structure stiffness at different temperatures on the same of excitation frequency, the test data show that the stiffness of rudder specimen decreases with the increase of ambient temperature, which leads to the frequency of each order mode decreasing gradually.The modal parameters of rudder structure will be reduced due to high temperature, the research provides the experimental means and technical support for the thermal modal test of the following products.