Fatigue Analysis of Rounded Straight Beam Flexible Hinge_Hinge Knowledge_Tallsen 1

Abstract: The research results have shown that the notch shape of a flexible hinge plays a crucial role in its fatigue performance. However, the fatigue performance of flexible hinges with special notch shapes has not been systematically studied, which makes it a valuable research topic. Especially in the case of composite flexible hinges, it is important to calculate their fatigue life through finite element simulation experiments, as it can greatly contribute to the fatigue performance research of composite flexible hinges. Furthermore, the fatigue analysis of rounded straight beam flexible hinges under different boundary conditions is conducted using the finite element fatigue analysis method in order to obtain the life of the weak link of the flexible hinge. This analysis helps to determine the entire flexible hinge's service life, providing a theoretical basis for the design of new flexible hinges.

Flexible hinges are pivotal components in compliant mechanisms. While typical flexible hinges are widely used, they often come with limitations such as restricted movement space, weak strength, and limited applications. However, composite flexible hinges address these issues and offer advantages such as reduced clearance, higher positioning accuracy, and improved fatigue performance. Thus, composite flexible hinges have a promising future in precision positioning platforms.

In recent years, computer simulation technology has gained prominence in product development. Finite element simulation technology, in particular, is increasingly being utilized in fatigue analysis of product mechanisms. Compared to traditional fatigue analysis methods, finite element fatigue simulation technology allows for a more accurate determination of fatigue life distribution on the surface of parts. This helps to identify potential design flaws during the initial stages of product development.

This research focuses on a specific type of composite flexible hinge, namely the rounded straight beam flexible hinge. By conducting finite element fatigue simulation experiments, the fatigue life distribution of the surface of the rounded straight beam flexible hinge is obtained, allowing for the determination of its weak position. This analysis provides insights into the overall service life of the rounded straight beam flexible hinge.

The fatigue analysis process involves several steps, including structural analysis of parts to identify potentially dangerous areas, conducting S-N fatigue tests to obtain material-specific S-N curves, processing load spectra, and selecting appropriate fatigue damage accumulation theories to determine the fatigue life of parts.

The fatigue analysis of the rounded straight beam flexible hinge is conducted using the nominal stress method. The stress distribution on the surface of the hinge obtained through finite element analysis is imported into the fatigue analysis system. The S-N curve of the material is selected, and the load spectrum is inputted. By applying the appropriate fatigue damage accumulation rule, the fatigue analysis system determines the fatigue life of the dangerous parts of the rounded straight beam flexible hinge, thereby capturing the overall fatigue life of the hinge.

The expanded article further explores the fatigue analysis method and process, delves into the establishment of a mathematical model for the rounded straight beam flexible hinge, explains the finite element analysis of the hinge, and provides detailed information on the fatigue analysis of the hinge. The comprehensive research findings indicate that the rounded straight beam composite flexible hinge exhibits superior fatigue strength compared to other types of flexible hinges.

In conclusion, this research study showcases the importance of considering the notch shape of flexible hinges in determining their fatigue performance. It demonstrates the efficacy of finite element fatigue analysis in evaluating the fatigue life of composite flexible hinges. The study specifically emphasizes the fatigue analysis of rounded straight beam flexible hinges and highlights the need for further research on other curved flexible hinge designs in future studies.