The structural parameters of the planar S-type microspring take into account the complex structure of the planar S-type microspring. In order to make the modeling and analysis simple and make the finite element calculation result accurate, the three-dimensional finite element model of the microspring is established by 1:1 ratio. The cross section in the thickness direction is first constructed and meshed with the PLANE82 unit, and then stretched into several SOLID95 units in the thickness direction to form a finite element solid model.
Specific steps: (1) After entering ANSYS, set the calculation type to Structural. Since the microspring size is on the order of millimeters, the three basic units of the input parameter values ​​are selected to be micrometers (μm) and the mass is kilograms (kg). The time is seconds (s) and the other units are the expressions they make up.
(2) The material property is defined as a linear elastic isotropic body. The elastic modulus EX of UV-LIGA nickel is “1.8×105 MPaâ€, the Poisson's ratio PRXY is “0.3â€, and the material density DENS is “8.9×1015 kg/μm 3â€. . The 12 key points of a microspring are generated, and then the key points of the remaining 6 microsprings are copied from the end, and then the key points are sequentially connected to form a closed curve, thereby generating the entire microspring cross section, as shown. The generated cross section is divided into grids by the PLANE82 unit, and the unit length is set to "20". Then, using the "Extrude" command, the cross section of the mesh is stretched in the thickness direction into a mesh entity having a SOLID95 unit, and the number of the tensile units in the thickness direction is set to "5" as shown.
The finite element analysis of stiffness characteristics is carried out according to the above finite element analysis process, and ANSYS is incremented ten times according to a certain structural parameter. The other parameters are unchanged. Five sets of finite element simulation calculations are performed on the plane S-type micro to analyze the stiffness characteristics. The spring constant calculated by finite element simulation varies with a certain structural parameter, that is, the stiffness of a planar S-type MEMS spring increases with the increase of its line width or thickness, with the increase of its spring width, beam spacing or number of segments. And the decrease, wherein the line width has the most obvious influence on the stiffness.
Conclusion The innovation of this paper is that the actual finite element analysis software--ANSYS simulates the mechanical properties of planar S-type MEMS springs.
The modeling method presented is simple and yields high computational accuracy. The influence of structural parameters on the stiffness of microsprings is obtained by finite element calculation, which provides an effective method for accurately determining the elastic performance and has practical application value. The research results and analysis methods in this paper can be used as the basis for further optimizing the design of microsprings to meet the needs of MEMS.
C Ring,Flocking Spring,ARC Spring
Compression Springs ,Stampings,Extension Springs Co., Ltd. , http://www.ns-springs.com