Finite element method design and performance analysis of a new large-angle flexible hinge_Hinge Know

Abstract: The development of flexible hinges with large deformation, small stress, and small center drift has always been a challenging problem in the field of flexible hinge research. This paper presents a novel design of a flexible hinge with a V-shaped structure, superposition theory, and symmetrical layout method, inspired by a certain foreign flexible hinge. A conceptual study was conducted to design this flexible hinge, establish a mathematical model, and analyze its performance. Finite element method analysis demonstrated that the design method increased the flexibility of the hinge by lengthening the section, reduced its center drift and maximum stress, resulting in a maximum rotation angle of approximately 16°, a maximum center drift of 3.557 μm, and a maximum stress of 499.8 MPa, meeting the initial design requirements. These results confirm the practical value of the hinge.

Currently, space optical remote sensors mainly adopt the TDICCD staggered splicing method to achieve long line arrays. However, this method lacks image motion compensation, leading to a significant reduction in image resolution. Therefore, image motion compensation is necessary. Mechanical image motion compensation and electronic compensation are the two common methods. This paper focuses on the real-time control of the TDICCD device's rotation to achieve image motion compensation. Ordinary rotating mechanisms are unable to meet the precision requirements in space, necessitating the development of flexible hinges with no gap, no friction, no lubrication, and high resolution. The hinge developed in this paper is based on a specific camera design, requiring a rotation angle of 6-8°, center drift not exceeding 10 μm, and dimensions within 40mm×60mm.

Flexible hinge design:

Several typical flexible hinge designs are introduced, including the staggered flexible hinge, split-tube flexible hinge, and free-flexing flexible hinge. While these hinges exhibit good flexibility and a large range of rotation angles, they suffer from significant center drift when subjected to external forces. The common characteristic of these hinges is the use of multiple reeds for deformation, achieving concentrated deformation through distributed flexibility. However, the structural stability of multi-reed configurations is difficult to ensure in the space environment. Therefore, the need for further research to apply these components to space is emphasized. To address these issues, a new butterfly flexible hinge design is proposed, incorporating a V-shaped design and symmetrical structure, inspired by the wheel-type flexible hinge.

Analysis of Butterfly Flexible Hinge:

The geometric model of the butterfly flexible hinge is analyzed using the finite element method. The hinge is composed of interconnected hinges with a V-shaped design, enabling increased length of the flexible unit without compromising its thickness. The analysis demonstrates that the design effectively reduces stress by distributing the force across four parts and implementing vector offset to minimize center drift. The maximum stress is approximately 499.8 MPa, within the allowable stress range of the chosen material. The hinge achieves a rotation angle of 8° and a center drift of 3.557 μm, meeting the design requirements. The relationship between the radius and center drift is also investigated, with a 17mm radius deemed optimal for the hinge design. Additionally, the analysis reveals a linear relationship between force and displacement, enabling precise control of the rotation angle.

In conclusion, a new type of large-angle flexible hinge is designed using the finite element method, and its performance is analyzed. The proposed V-shaped design, superposition theory, and symmetrical layout result in increased flexibility, reduced center drift, and stress. The hinge achieves a maximum rotation angle of 16°, a maximum center drift of 3.557 μm, and a maximum stress of 499.8 MPa, meeting the design requirements. The analysis of the force-displacement relationship further confirms the hinge's excellent linear elasticity. Overall, the developed hinge exhibits practical value and can be applied in various scenarios, such as opening ceremonies, business exhibitions, and product promotions.