This technology defines a novel smoothing function model that seamlessly connects discontinuous sections of gap-type nonlinearities, such as gear backlash, using an nth-order polynomial. It involves validating the key smoothing coefficient (ε2) across specific ranges and investigating its impact on gear impact response through Harmonic Balance Method (HBM)-based simulation for real-vehicle driveline analysis.
The discontinuous contact and non-contact behavior resulting from gear backlash has historically caused convergence issues when simulating nonlinear rotating systems. While smoothing functions have been used to mitigate this, their specific functionality and error characteristics remained unclear, and they were limited in their ability to predict results under various nonlinear conditions.
This technology ensures the polynomial is tangent to the gear mesh stiffness (2.7×10^8 N/m) and limits the order to even numbers to exclude physically impossible negative mesh forces. By focusing on a single unloaded gear pair, it analyzes vibration impacts, including super-harmonic components. It provides criteria for setting the smoothing coefficient, noting that while higher values improve convergence, exceeding certain thresholds or applying them to non-impact frequency bands increases error. Applicable to automotive driveline software and gear noise prediction modules, it enables rapid, accurate nonlinear frequency response results without convergence failure.
This invention was developed with support from the Ministry of Education for research on the development of vehicle system driveline analysis and measurement experiments to resolve gear rattle and whine noise.
WO2018-143513A1
