介绍了研究柔性铰链机构屈曲特性的重要意义。利用材料力学弯曲变形理论的挠曲线近似微分方程建立了计算直角切口柔性铰链平行四杆机构屈曲临界力的数学模型。在简单可靠的实验装置上测试了实际样件的屈曲临界力,并利用商用有限元软件ANSYS8.0对相应的四杆机构模型进行了非线性屈曲分析。最终结果表明:理论值、实验值以及仿真值都十分接近,但仍存在一定的误差,通过原因分析,证实了存在这种误差的合理性,从而验证了所建数学模型具有较高的参考价值,可以作为柔性铰链平行四杆机构屈曲优化设计的指导理论。
The importance of the study on buckling performance was presented. The mathematical model, used to calculate the buckling critical force of compliant parallel four-bar mechanism with right-angle-notch flexure hinges, was established with the approximative differential equations of the flexible curve based on the bending theory in strength of materials. The buckling critical force of the sample was tested on the simple and reliable experimental equipment. Meanwhile, the nonlinear buckling analysis was carried out using the finite element model (FEM) method. The values of the buckling critical forces obtained from the calculation of the mathematical model above, from the experimentation and from the simulation all met well except the slight errors among them, which indicates the correctness of the mathematical model. Moreover, the sources of error were traced and validated the error's existence. In summary, the mathematical model proposed above has high value for reference in buckling optimization design of compliant parallel four-bar mechanism.