Flexure hinges are the key components of high-precision flexible mechanisms. Their motion precision and range affect the performance of flexible mechanisms. Herein
the flexibility matrix of a circular flexure hinge was derived for optimal design. The flexibility equation of the circular flexure hinge was established using the structure matrix method. The warping and torsional stiffness of the rectangular section was deduced. The approximate equation of torsional flexibility under constrained torsional state was obtained
providing a basis for the exact solution of torsional stiffness of the hinge with small relative length. Compared with the finite element method
the maximum relative error of torsional flexibility is approximately 10%
and the relative error of the remaining flexibility is less than 6%
which verifies the accuracy of the flexibility equation. The sensitivity of the design parameters of the flexure hinge to rotational stiffness was obtained by the orthogonal experimental design. The rotation ability and axial stiffness of the flexure hinge were optimized by the multi-objective genetic algorithm. By comparing the optimization results with the parameters selected according to the design experience
it is found that the bending flexibility of the optimized circular flexure hinge increased by 5.12% and the axial stiffness of the hinge increased by 4.72%. It is proved that the optimal design of the circular flexure hinge has obvious effects.
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references
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