A customizable overconstrained multibody mechanism with reaction forces measurement system

Abstract In the process of formulating and optimizing modern methods for accurate and effective modeling of mechanical systems, an important step is validation. The presented research aims to design a test bench devoted to the experimental investigation of an overconstrained mechanism based on a benchmark multibody system and to collect force measurements while the system is stationary or in motion. The hardware realization of a previously developed theoretical model is presented, with special attention paid to minimizing the effects of friction, drag, backlash, and manufacturing inaccuracies. In order to achieve this, low-friction, low-backlash joints are used, the lengths of all the links are adjustable, and the mechanism parts of various stiffnesses are designed. The system is also prepared to deliberately introduce assembly stresses by changing the links’ lengths. The stiffness of crucial components was experimentally verified, and the developed FEM model of the mechanism’s frame was validated against measurement data. Finally, the constructed test bench is demonstrated to perform measurements reliably, providing accurate, consistent results. The experimentally obtained force data are compared with the loads predicted by numerical analyses, confirming that the stand may be used to validate multibody modeling methods.