Instability Study Of Functionally Graded Micro-Beam Under The Thermal-Mechanical-Electrical Multifield Coupling

摘要

With the improvement of Micro-Electro-Mechanical Systems(MEMS), which include miniature structure, miniature sensor, actuator, control circuit, communication, and power supply in one or more chips, the Functionally Graded Materials (FGMs) gradually used in MEMS. The functionally graded microstructures can be used in many new technologies, especially in intelligent robots and biomedicine. Therefore, it is important to further analyze the mechanical limit of this particular fine structure. In this paper, as stated by von Karman's nonlinear geometric theory, a mechanical model that could describe the pull-in unsteadiness of a micro-beam made for metal also ceramic is established under consideration of intermolecular Casimir force, electric field power, and temperature change. Then, so as should faultlessly tackle those dimensionless nonlinear control equations, the differential quadrature method (DQM) was adopted. Finally, by solving the governing equation, the mechanical relationship of the microbeam composed of ceramic and metal according to a certain power function law is analyzed under the influence of size effect parameters, geometric parameters, and applied forces. The consequences of parameter analysis indicate that the size effect and Casimir force contribute significant influences on the pull-in instability characteristics NiTi-SiC micro-beam.