【作者】 朱明；

【导师】 王卫英；

【作者基本信息】 南京航空航天大学 ， 机械设计及理论， 2011， 硕士

【摘要】 本文针对弹性铰链传统分析方法中存在的不足之处,通过理论、仿真和试验三者相结合的方法,对微位移机构中弹性铰链的失稳(屈曲)和刚度问题进行了研究。依据材料力学能量原理中的瑞利-里兹法,针对多节串联直角切口型弹性铰链和直角切口型弹性铰链平行四杆机构,建立了屈曲临界载荷力学模型并推导了相关计算公式,综合考虑了弹性铰链的连杆长度对其屈曲的影响;依据卡氏定理推导了双曲线型及椭圆型弹性铰链的柔度计算公式;采用伪刚体模型法推导了直角切口型及椭圆型弹性铰链平行四杆机构静刚度计算公式。利用有限元软件对直角切口型弹性铰链及其平行四杆机构模型进行了屈曲仿真分析,包括特征值屈曲分析和非线性屈曲分析;计算了双曲线型及椭圆型弹性铰链的柔度、直角切口型及椭圆型弹性铰链平行四杆机构的静刚度。制作了直角切口型弹性铰链及其平行四杆机构的样件,设计了试验装置,分别进行了屈曲和刚度试验,得到了相关的试验数据。通过在不同尺寸参数下的屈曲和刚度分析,比较了理论计算值、有限元仿真值及相关试验数据,证明了本文所建力学模型及推导公式的正确性。更多还原

【Abstract】 Research of collapse and stiffness for flexible hinges in a micro-displacement mechanism are accomplished through the combination of theoretical, simulation and experiment, in order to overcome the difficulties in the traditional method.Based on the Rayleigh-Ritz method mentioned in the principles of energy, a mechanical model of critical buckling force is established for the computation of critical force for parallel four–bar flexible hinge mechanism, which is composed of right-angle-notch flexible hinges. The related formula is derived, while the length of flexible hinge is considered. Castiglione theorem is applied to the derivation of flexibility for hyperbola and ellipse flexible hinge. And theoretical expressions for mechanism, which is composed of static stiffness in right-angle-notch flexible hinges and parallel four–bar flexible ellipse hinge, are given depending on Pseudo-rigid-body model method.Right-angle-notch flexible hinges and parallel four–bar flexible hinge mechanism are analyzed for buckling using finite element software, including the eigenvalue buckling analysis and nonlinear buckling analysis. Flexiblity is calculated for hyperbola flexible hinge and ellipse respectively. Static stiffness is calculated for right-angle-notch flexible hinges and parallel four–bar flexible ellipse hinge mechanism.We produced a Right-angle-notch flexible hinges and parallel four–bar flexible hinge, and designed an experimental device. Buckling and stiffness were carried out by experiment, and related measurement data were obtained. The accuracy of mechanical model and derived formula are proved by comparison of the theoretical data, the data of the finite element simulation and experimental data related by the analysis of buckling and stiffness with different sizes parameter configurations.更多还原