高温材料的阻尼特性实验研究

Experimental Research on Damping Measurement of High-Temperature Materials

摘要:

采用双悬臂梁试件，通过基础激励下的共振驻留法，开发了一套高温材料在真空环境下的阻尼测试系统。研究了提高测试精度的方法，并分析了空气阻尼对阻尼测试结果的影响，并以Ti-6-4合金为对象，研究了阻尼随温度、应变幅值及振动频率的变化规律

关键词:材料阻尼;共振驻留;双悬臂梁

Abstract:

A damping measurement system was developed for high temperature materials using double-reed cantilever specimens by means of resonant-dwell under base excitation in a high-temperature and vacuum environment. Some methods were proposed to improve the accuracy of damping measurement. The effect of air damping on damping tested results was analyzed. The damping of Ti-6-4 alloy was tested by the system and the relationships of material damping to temperature, strain amplitude and vibration frequency were studied. Results show that air damping has a significant effect on the damping of materials. The damping of Ti-6-4 alloy keeps constant and the vibration frequency has little effect on it below 400 oC. However, it increases rapidly with temperature elevation above 400 oC and the vibration frequency has a complicated effect on it. The effect of strain amplitude on the damping of Ti-6-4 alloy can be neglected in the temperature range from 25 to 600 oC

Key words:material damping; resonant-dwell; double-reed cantilever