Bending, Tensile and Compressive Stiffness Analysis and Application of Four Composite Flexible Hinge

Summary: This article provides an analysis of the stiffness properties of four composite flexible hinges. It begins by deriving the calculation formulas for bending stiffness, tension, and compression stiffness of four different types of flexible hinges based on material mechanics and calculus. Using the finite element method, the author verifies the correctness of the derived stiffness calculation formula for the rounded straight beam flexible hinge.

The article then compares and analyzes the stiffness properties of four different composite flexible hinges. It shows that the elliptical straight beam composite hinge has the smallest bending and tensile stiffness.

Next, the author analyzes the stiffness performance of flexible T-shaped joints using the finite element method. It is found that the flexibility and deformation compensation ability of the flexible T-shaped joint composed of the elliptical straight beam composite hinge is the strongest.

Flexible hinges are widely used in applications that require small angular displacement and high-precision rotation. They eliminate air travel and mechanical friction during transmission. Stiffness is a crucial performance indicator of flexible hinges as it reflects their ability to resist external loads and the flexibility of kinematic pairs.

The article notes that previous studies have derived complex formulas for calculating the stiffness of flexible hinges. In this research, the author uses the basic formulas of mechanics to derive more concise expressions. However, due to the geometric dimensions of the actual flexible hinges not fully meeting the assumptions of theoretical analysis, finite element methods are often employed to study their stiffness performance.

Based on the rounded straight beam flexible hinge, the author proposes three new composite flexible hinges: elliptical straight beam composite, parabolic straight beam composite, and hyperbolic straight beam composite hinges. The stiffness calculation formulas for these four types of flexible hinges are derived, and their stiffness properties are compared and analyzed.

To demonstrate the application of these findings, the article investigates the stiffness properties of flexible T-shaped joints using the four composite flexible hinges. The results show that the flexible T-shaped joint composed of the elliptical straight beam composite hinge exhibits the strongest deformation compensation ability.

In conclusion, this research provides valuable insights into the stiffness properties of different types of composite flexible hinges. The findings can inform the design and application of flexible hinges in various industries, particularly in applications that require precise rotation and minimal friction.