Publications

The continuously rising demands for precision favour the application of monolithic compliant mechanisms with flexure hinges in various fields of precision engineering. It gives way to an almost frictionless and precise motion even under vacuum conditions. These advantages have made compliant mechanism an integral component of high precision weighing cells. A downside of compliant joints is their stiffness towards deflection, which limits the sensitivity of the overall system. Consequently, the flexure hinges are manufactured as thin as possible. The present limit in terms of manufacturing technology is within the range of 50 [my]m. The objective of predicting the behaviour of highest precision weighing cells by modelling is directly interconnected with the exact knowledge of the behaviour of flexure hinges in terms of stiffness. Especially, for flexure hinges with high aspect ratios, typically found in weighing cells, the existing analytical equations and finite element models show pronounced deviations. The present research effort is dedicated to a clarification of this observation. Structure mechanical finite element models are developed to identify the deviations of the models precisely. Results obtained are compared to analytical results and conclusions for the modelling of thin flexure hinges are drawn.