MÔ PHỎNG CẢM BIẾN GIA TỐC ÁP ĐIỆN TRỞ BA BẬC TỰ DO

This paper presents the modeling and simulation results of the mechanical behaviour and output characteristics of a three degree of freedom (3-DOF) piezoresistive accelerometer with outer size of 1 x 1 mm 2 based on the finite element method (FEM) using ANSYS software. The SOLID 226 element is used for coupled-field analysis of piezoresistive sensor. The stress distributions along the mechanicasl sensitive beams have been analyzed. The obtained results of this analysis were used to determine the location of piezoresistors.. Corresponding to three space directions, i.e., x, y and z, the natural frequencies are 600110 Hz, 600110 Hz and 46494 Hz, respectively. The sensor sensitivity increases with decreasing the thickness and width of the sensing beam. but declines with decrease of the seismic mass weight. For the accelerometer with sensing beam dimensions of 340 m x 60 m x 10 m, the sensitivities are 38.8 mV/g, 38.8 mV/g and 23.3 mV/g corresponding to x, y and z direction, respectively. The simulation results will be used for design and produce this type of sensor.