Fatigue Experiment and Analysis of Electro-Thermal Actuators
| Autor: | Chiu-Chung Rong, 邱重榮 |
|---|---|
| Rok vydání: | 2003 |
| Druh dokumentu: | 學位論文 ; thesis |
| Popis: | 91 Fatigue analysis for planar flexural (U shaped) and bent-beam (V shaped) electro-thermal micro actuators is performed in this study. In addition to laboratorial fatigue life observations, finite element software, ANSYSTM, was adopted to interpret the S-N curve for the actuators. The influences of input power, operation frequency and temperature distribution on fatigue life are also investigated. A model of equivalent damping and damping ratio is also developed in the study and its results reveal that reasonable deflection range and operation frequency window for the micro actuators can be achieved. Based on the results, it is concluded that as driving electrical power increases, temperature range in actuators elevates that in turn yields internal stress range; therefore, shortens the fatigue life of the actuator. At the condition of constant driving power, higher operation frequency that limits the flexural deflection for the actuator results in longer fatigue life. Size effect on fatigue life is also observed, i.e. bigger actuators tend to deliver shorter fatigue life. However, the phenomenon is not obvious as the size of the actuators is raised further. The numerically structural dynamical analysis shows important influence of camping effects on the dynamical behavior as well as the fatigue life of the U-shaped actuators. Damping effects including air viscosity, friction force and material damping reflects the reduction of cutoff frequency. However, damping effect is insignificant on V-shaped actuators due to its higher stiffness in flexural direction than its counter part of U-shaped actuators. |
| Databáze: | Networked Digital Library of Theses & Dissertations |
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