MBS Gear-tooth Stiffness Model: Implementation of a new coupling model for fast and accurate simulation of gear pairs using stiffness characteristic arrays

摘要

The simulation of gear trains is important to understand the behavior of systems and their components in many industrial applications, especially in regards to acoustics, fatigue, and wear. However, there is a visible mismatch in the degree of detail between the existing gear simulation models. On one hand, most MBS models use rigid tooth-bodies with constant stiffness that is independent of the contact point and the load case. This results in simulation inaccuracies, especially regarding proper load application and stiffness distribution which leads to imprecise acoustic and fatigue estimations. On the other hand, most of the current elastic tooth stiffness models use in-depth contact and impact calculations which result in a slow and computationally-intensive simulation process that cannot be applied to large multi-body dynamic systems. MBS Gear-tooth stiffness is an FVA project that aims to help bridge the gap between the two aforementioned approaches. It is implemented as a Simpack user-routine, which provides a flexible and powerful modeling environment with advanced processing tools. It contains five different calculation approaches - Constant stiffness, Stiffness Array (STIRAK import), Fourier Function, Gear Data Input, and Constant Stiffness with DIN 3990 models - that define the stiffness distribution along the tooth flank, and can be accessed in the parameter window through a selection menu:. The Stiffness Array model is the main focus of this paper. It uses pre-calculated stiffness characteristics from the FVA program FE-Stirnradkette (STIRAK) developed by the WZL. These arrays are calculated based on the material and geometry of the teeth and gear bodies and can be imported to Simpack as an external file. This model represents a more realistic behavior of gears than the standard MBS models without delving into contact and impact analysis, and therefore can be used in large multibody systems without being computationally intensive. Hence, MBS Gear-tooth stiffness provides the first step in bridging the gap between the degrees of complexity in the current models. Future research is also planned to further expand the model by incorporating elastic tooth bodies and different representations of load distribution along the flank.