Design Evaluations of IKEA friction hinge
Examensarbete för masterexamen
The goal of this master thesis conducted with IKEA was to better understand the friction hinge technology and advance IKEA's development effort in this direction, based on the initial design of the hinge provided by them. Research questions to be answered were, among others, what are different types of such hinges, how to predict the torque produced, and which parameters influence the torque. The aim of the study was achieved by performing a mix of theoretical background studies, patent study, Finite Element Analyses, and experimental studies on physical prototypes. The Finite Element Analysis, done using ANSYS Workbench, was the main part of the project and included establishing 2D and 3D static structural models and performing simulations on them. The models were then calibrated and validated against the experimental data. The numerical models reflected the reality well with an error of less than 20% in most analyzed cases. However, the experimental results had a high variance and did not correspond to expected boundary conditions. Optimization of the models allowed to reduce the simulation times to several minutes for 2D and 3-5 hours for 3D simulations while maintaining roughly the same quality of the results. Computationally inexpensive models made it possible to observe how the results change after altering some of the parameters. The studies on the numerical model showed that the interference depth is for such geometry not as crucial as the thickness of the part on shaft and coefficient of friction. Nevertheless, the high variance in the experimental study proved, that the problem is much more complex than expected and there are more factors in the design-manufacturing-assembly chain that influence the torque. That implies that a high factor of safety is needed for the product to be safe and reliable.
Friction hinge , Finite Element Method , experimental testing , pattern study