开式十字截面柔性支承的力学特性分析

Study on mechanical properties of flexible bearing with open-cross section

对于精密仪器中能提供精密有限转动的开式十字截面柔性支承进行了力学特性分析,在有限弹性变形范围内给出了轴向刚度、横向刚度、弯曲刚度、扭转刚度解析计算表达式,基于第三强度理论给出了相当应力.按照不同载荷和边界条件,采用有限元的方法进行了模拟工况计算,讨论了有刚度系数的有限元解和解析解偏差及其原因.结果表明:解析计算得到的刚度系数和最大应力值与有限元解比较一致,所给出的解析计算公式可用于开式十字截面柔性支承的工程设计.

The mechanical properties of the flexible bearing with open-cross section that ts usually useu to provide limited accuracy angular displacement in precision instruments are discussed. The calculation ex- pressions of axial stiffness, off-axis stiffness, bending stiffness, torsion stiffness, of the flexible pivot bear- ing with a limited range of elastic deformation are given. The expressions of the equivalent stress are also presented by using the third strength theory. The loadcases under different loads and boundary conditions are simulated by employing the finite element method. Both errors between the analytical solutions and simulation solutions of the stiffness coefficients and the error sources are investigated. The results show that the analytical solutions of the stiffness coefficients and the maximum stress are consistent with their simulation solutions basically. The presented expressions can be adopted for engineering design of the flexible bearing with open-cross section.