Analytical and experimental characterization of nonlinear coned disk springs with focus on edge friction contribution to force-deflection hysteresis

Even though coned disk springs are widely used given their highly customizable design features, the literature on both analytical and experimental characterizations is sparse. This article overcomes the void by focusing on midrange displacements for a commercially available coned disk springs with square edges. A refined single disk spring model, capable of having asymmetric friction conditions imposed on the disk spring edges, is developed to predict the load-deflection and quasi-static hysteresis characteristics while relaxing prior limiting assumptions. A new quasi-static experiment is then proposed to measure the nonlinear load-deflection characteristics under four principal interfacial edge configurations - two symmetric and two asymmetric. In particular, the asymmetric friction conditions afford the opportunity to assess the validity of the long standing theory concerning the assumed location of the disk spring cross section rotation point. The imposition of asymmetric friction conditions on the disk spring also allows for the direct quantification of the contribution of asymmetric friction conditions on the disk spring contact edges. New analytical and experimental studies show that there are significant edge friction contributions to the hysteresis exhibited by the disk spring. Finally, stiffness parameters from both theory and experiment are briefly evaluated over midrange displacements.