Hole (notch) flexure hinge

Normal and rotational stiffness, and maximum rotation angle, of a circular-hole (notch) flexure hinge in a flat plate.

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Hole diameter, D10⁻³ mNeck height, h10⁻³ mPlate thickness, t10⁻³ mYoung's modulus, E10⁹ PaPoisson's ratio, νYield strength, R_p0.210⁶ Pa

Plane-strain modulus, E'78.02 10⁹ Pa

Normal stiffness, c_xx118.42 10⁶ N/m

Shear/normal stiffness ratio0.1 -

Torsional (bending) stiffness, k = dψ/dT23.06 Nm/rad

Maximum rotation angle, ψ_max19.2 10⁻³ rad

Maximum rotation angle, α_max1.101 deg

Maximum torsion moment, T = kψ0.443 Nm

Method & references

Design chart for hole (notch) flexure hinges (Fig. 14.6).

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Hole (notch) flexure hinge — Engineering ABC