Reconfigurable ADAMS Modeling of Localized Bearing Defects: Validation and the Role of Modeling Choices in Dynamic Response

Localized defects in rolling-element bearings produce vibration responses governed by contact events, load transmission, defect geometry, and system dynamics. To examine these mechanisms in a controlled and reconfigurable setting, this paper presents an MSC ADAMS framework for localized bearing faults, demonstrated on an SKF 6208 deep groove ball bearing with outer-ring spalls. The framework is evaluated against experimental test-rig measurements and a legacy 3D MATLAB bearing model, with healthy bearing contact forces checked against analytical load-distribution theory. The ADAMS model reproduces the spectral structure (including BPFO harmonics and selected modulation features), defect-interaction timing, and trends across defect sizes, though not absolute vibration amplitudes, while providing access to internal contact forces during defect interaction. This combination is used to examine two modeling issues that affect the mechanical interpretation of simulated bearing fault response. First, the outer-ring support definition controls the effective load path: adding support stiffness can transfer part of the applied load directly to the ground, reducing the load carried through rolling contacts. Second, the defect exit response depends on local contact formulation and geometric discretization. The legacy MATLAB model, based on a single-point Hertzian contact formulation, produces a sharper exit rebound, whereas the geometry-based ADAMS contact produces a more gradual return to the load zone. The study therefore contributes not only a validated simulation framework, but also mechanistic insight into how support and contact modeling choices shape the vibration and contact force responses used in bearing fault diagnostics, prognostics, and physical interpretation.