• CN：11-2187/TH
• ISSN：0577-6686

• 材料科学与工程 •

交流电作用下电热致动器的热疲劳失效机理研究*

1. 1. 上海大学机械自动化工程系 上海 200072;
2. 兰州城市学院石油工程学院 兰州 730070
• 出版日期:2016-09-20 发布日期:2016-09-20
• 作者简介:

作者简介：王振禄，男，1980年出生，博士，讲师。主要研究方向为MEMS器件设计、MEMS力学性能分析。

E-mail：wangzl1928@shu.edu.cn

沈雪瑾(通信作者)，女，1963年出生，博士，教授，博士研究生导师。主要研究方向为MEMS机械学、摩擦学。

E-mail：shenxj@shu.edu.cn

E-mail：xychen@shu.edu.cn

• 基金资助:
* 国家自然科学基金资助项目(51075249); 20151022收到初稿，20160325;

Study on Thermal Fatigue Failure Mechanisms of Electrothermal Actuator with Alternating Current Loading

WANG Zhenlu1, 2, SHEN Xuejin1, CHEN Xiaoyang1

1. 1. Department of Mechanical Automation Engineering， Shanghai University， Shanghai 200072;
2. School of Petroleum Engineering， Lanzhou City University， Lanzhou 730070
• Online:2016-09-20 Published:2016-09-20

Abstract:

：To counter the thermal fatigue failure of electrothermal actuator caused by the alternating temperature loading due to alternating current (AC), the failure mechanisms of the thermal fatigue failure is analyzed. The transient temperature analysis model and the mechanical model of the actuator are developed. The output displacement of actuator is measured and the experimental results are in good agreement with the theoretical predictions and finite element analysis. The relationships between temperature and the frequency or amplitude of the AC are analyzed. The results show that the structure and the applied voltage levels have significant influence on the temperature distributions and the value of the stress and the stress is not the dominant thermal fatigue failure mechanism for the maximum stress below the yield stress of the material. The relationships between displacement and number of cycles of the electrothermal actuator with AC loading are tested, it is indicated that the thermal fatigue failure won’t take place when electrothermal actuator working below ductile-brittle transition temperature, otherwise, thermal fatigue failure will occur after long-term cyclic loading. It is confirmed that the temperature between 300 ℃ to 600 ℃ is comparatively suitable for electrothermal actuator according to theoretical and experimental analysis, and the actuator is able to provide accurate and stable number of cycles for tens of millions. Thermal fatigue failure mechanism of electrothermal actuator is analyzed. The analysis indicates that high temperature deformation is the direct reason for thermal fatigue failure, and the frequency and amplitude of the AC which effect on thermal fatigue can be treated as the effects caused by temperature.