Analysis of belleville spring systems using numerical andfinite element methods (FEM)

In this study, the mechanical performance of disc springs from different series (A, B, C, and custom-made) was comprehensively investigated. For each disc geometry, both linear and nonlinear finite element analyses were performed, and the results were compared with the DIN EN 16983 standard and manufacturer catalog data. The evaluation was conducted based on three main performance criteria: the force value at 75% deflection (F0,75), Von Mises stress distribution, and normal stress values. The findings indicate that linear analysis provides sufficiently accurate predictions for springs operating under small deformations within the elastic range; however, nonlinear modeling becomes indispensable for springs subjected to large deformations. In nonlinear simulations, F0,75 values were generally lower than those found in catalogs and standards, due to the inclusion of plasticity effects. Von Mises stress distributions revealed that many springs approached or reached the material yield limit, especially with stress concentrations observed near the outer edges. Normal stresses exhibited a radial decay pattern consistent with the springs' symmetrical geometry. One of the key contributions of this research is the engineering-level evaluation of the potential use of disc springs in seismic isolation systems. Disc springs offer significant advantages for such applications, including energy dissipation through material and contact behavior, re-centering capability due to symmetric geometry, modularity through serial or parallel configurations, and compactness compared to other damping systems. Furthermore, this study highlights several areas for future development, including hysteretic performance under cyclic loading, experimental validation of numerical models, and exploration of hybrid systems incorporating disc springs with other passive or semi-active devices. In conclusion, this thesis demonstrates that disc springs possess high potential for use in structural seismic isolation systems, particularly in terms of stiffness control and energy dissipation capacity.