梯形变截面梁蟹腿加速度计系统设计

SYSTEM ANALYSIS OF THE FOUR-PRONG LEGGED ACCELEROMETER BASED ON TRAPEZOIDAL VARIABLE CROSS-SECTION BEAM

结合蟹腿加速度计系统动态响应、稳定性和灵敏度对支撑梁刚度的要求,设计并优化了一种梯形变截面梁,满足加速度计的不同方向刚度要求。建立加速度计的动力学模型,得到系统动态响应性能参数与梁刚度关系;建立梯形变截面梁纯弯曲的数学模型,推导出梯形变截面梁刚度和尺寸关系;分析强度对尺寸要求;通过对加速度计系统稳定性和灵敏度分析,对梁结构提出了要求。在非检测方向同等刚度条件下,梯形变截面梁与等截面梁相比,危险截面处应力相当而检测方向刚度减小,系统灵敏度提高,提高系统动态输出特性,质量大幅减轻。

Combining the four-prong legged acceleration system dynamic response,stability and sensitivity of support stiffness,a trapezoidal beam with variable cross section was designed and optimized. The dynamic model of the accelerometer was established and a relationship was found between the system dynamic response parameters and the beam rigidity. The trapezoidal variable cross-section beam rigidity-size relation was deduced with a bending mathematical model. The size requirements were raised by strength. By analyzing the system stability and sensitivity of the accelerometer,the beam rigidity was obtained.Compared with uniform cross-section under the equal rigidity in the no-detection direction,the trapezoidal variable section beam reduces the stiffness in detection direction with the equal stress on the critical section,improves the system sensitivity and dynamic output characteristics. However,quality greatly reduces.