This bachelor's thesis investigates mechanical joint simulators used for testing and calibrating industrial screwdrivers. The objective was to analyse existing simulator concepts, identify the most suitable force-generating element, and develop a concept of a simulator with adjustable stiffness. The theoretical part presents the fundamentals of bolted joints, the influence of friction on the relationship between tightening torque and preload, and a review of commercially available mechanical simulators. A comparative analysis showed that Disc Springs provide the most suitable solution due to their high load capacity, modularity, compact design, and long service life. Analytical calculations of preload, friction losses, and the dimensioning of key simulator components were performed. The analytical models were validated through experimental measurements at different torque levels. The results demonstrated good agreement between calculated and measured values together with high repeatability of the simulator. Based on these findings, a concept of a new mechanical joint simulator with adjustable stiffness was developed, enabling the simulation of different joint characteristics using a single device. The proposed design improves the flexibility and applicability of conventional mechanical simulators while maintaining high measurement reliability and repeatability.
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