结构参数对并联型双轴直圆柔性铰链刚度的影响

Effect of Structural Parameter on Stiffness of Parallel Two-axis Straight Circular Flexible Hinge

为了深入分析并联型双轴直圆柔性铰链的微位移变形性能,基于弹性梁的小变形假设、变截面连续梁弯曲理论及微积分叠加原理,推导出其角变形及转角刚度计算公式;根据胡克定律,得到拉压变形时的伸长量和拉伸刚度计算公式,并对柔性铰链在不同结构参数下进行有限元分析;同时,对影响转角刚度和拉伸刚度的结构参数进行研究。结果表明,转角刚度有限元解与解析解的误差在7%以内,拉伸刚度有限元解与解析解的误差在3%以内;刚度与最小厚度、弹性模量成正比关系,与切割半径成反比关系,且最小厚度对刚度的影响最显著,切割半径次之,弾性模量最弱。

In order to deeply analyze the micro-displacement deformation performance of parallel two-ax⁃is straight circular flexure hinge,based on the assumption of small deformation of elastic beam,the bending theo⁃ry of variable cross-section continuous beam and the principle of calculus superposition,the calculating formu⁃las of angular deformation and angular stiffness are derived.According to Hooke's law,the calculating formulas of elongation and tensile stiffness for tension-compression deformation are obtained,and the flexure hinge under different structural parameters is also calculated.Finite element analysis is carried out,and structural parame⁃ters affecting angular stiffness and tensile stiffness are studied.The results show that the error between finite ele⁃ment solution and analytical solution of angular stiffness is less than 7%,the error between finite element solu⁃tion and analytical solution of tensile stiffness is less than 3%;stiffness is proportional to minimum thickness and modulus of elasticity,inversely proportional to cutting radius,and minimum thickness is proportional to ri⁃gidity.The effect of minimum thickness is the most significant,cutting radius is the second,and modulus of pra⁃seodymium is the weakest.