Methodology for reducing root and contact stresses in spur gears through ISO 6336 modeling, finite element validation, and response surface optimization

Abstract

This work presents a methodology for reducing root and contact stresses in spur gears through the combined use of ISO 6336 analytical models, finite element validation, and response surface methodology (RSM). Six key geometric parameters—module, pressure angle, addendum, dedendum, root fillet radius, and profile-shift coefficient—were investigated to quantify their influence on the tooth stress distribution. A design of experiments (DoE) based on RSM was implemented in Minitab® to explore the design space and model the relationship between geometry and stress response. Gear geometries were generated in KISSsoft® and refined in SolidWorks®, while meshing and analysis were performed in HyperMesh®. Analytical stress predictions were validated against finite element results, showing strong agreement within ±5%. The response surfaces revealed that module, pressure angle, and fillet radius are dominant in reducing root stress, while pressure angle and profile shift mainly govern contact stress. Following the proposed optimization strategy, average stress reductions of 30% in root and 8% in contact were achieved. The methodology provides a systematic and computationally efficient framework for geometry optimization, enhancing gear durability and mitigating fatigue-driven failures in precision mechanical systems.