EFFECT OF THE OPEN CRACK ON THE PULL-IN INSTABILITY OF AN ELECTROSTATICALLY ACTUATED MICRO-BEAM  

作　　者：Asadollah Motallebi Mohammad Fathalilou Ghader Rezazadeh 

机构地区：[1]Mech. Eng. Dept., Islamic Azad University [2]Mech. Eng. Dept., Urmia University

出　　处：《Acta Mechanica Solida Sinica》2012年第6期627-637,共11页固体力学学报（英文版）

摘　　要：In this paper, the effects of the open crack on the static and dynamic pull-in volt- ages of an electrostatically actuated fixed-fixed and cantilever micro-beam are investigated. By presenting a mathematical modeling, the governing static and dynamic equations are solved by SSLM and Galerkin-based Reduced Order Model, respectively. Then, each single-side open crack in the micro-beam is modeled by a massless rotational spring and the cracked mode shapes and corresponding natural frequencies are calculated by considering the boundary and patching con- ditions and using transfer matrix methods. Finally, the effects of the crack depth ratio, crack position and crack number on the pull-in voltage of the micro-beams are studied. It is shown that beside the residual stresses created in the machining process, the crack（s） can be initiated, growth and consequently change the pull-in voltage of the system by decreasing the natural frequencies. The results show that the crack position is effective beside the crack depth ratio in decreasing the pull-in voltage. Also it is shown that in the fixed-fixed micro-beam there are several points for the crack location in which, the pull-in voltage is extremum.In this paper, the effects of the open crack on the static and dynamic pull-in volt- ages of an electrostatically actuated fixed-fixed and cantilever micro-beam are investigated. By presenting a mathematical modeling, the governing static and dynamic equations are solved by SSLM and Galerkin-based Reduced Order Model, respectively. Then, each single-side open crack in the micro-beam is modeled by a massless rotational spring and the cracked mode shapes and corresponding natural frequencies are calculated by considering the boundary and patching con- ditions and using transfer matrix methods. Finally, the effects of the crack depth ratio, crack position and crack number on the pull-in voltage of the micro-beams are studied. It is shown that beside the residual stresses created in the machining process, the crack（s） can be initiated, growth and consequently change the pull-in voltage of the system by decreasing the natural frequencies. The results show that the crack position is effective beside the crack depth ratio in decreasing the pull-in voltage. Also it is shown that in the fixed-fixed micro-beam there are several points for the crack location in which, the pull-in voltage is extremum.

关 键 词：MEMS open crack ELECTROSTATIC pull-in instability 

分 类 号：O346.1[理学—固体力学] TS914.25[理学—力学]