Performance is key to success in many things. Gear applications are no different.
Envalior introduces a research initiative focused on the predictive modeling of sliding wear in fiber-reinforced thermoplastic spur gears. The study integrates advanced simulation techniques with experimental validation to explore the complex interplay between material behavior, contact pressure, and wear mechanisms. The approach aims to enhance the reliability of wear predictions in polymer gear systems, particularly under dry-running and lubricated conditions.
Stanyl®, the ultimate material for plastic gears
Envalior’s high-performance polyamide, Stanyl® PA46, is widely used in thermoplastic gear applications due to its superior wear resistance and thermal stability. However, translating material properties into accurate wear predictions remains a challenge, especially when simplified tribological tests fail to capture the intricacies of real-world gear operation.
This research addresses the limitations of conventional testing by combining full-scale gear testing with a Disc-to-Disc (D2D) tribological setup. The goal is to develop a robust modeling framework that accounts for fiber orientation, contact pressure, and temperature effects.
Figure 1: Image of the gear durability test setup (left) and the overmolded discs of the D2D setup (right).
Advanced simulation and experimental setups
The study employs a modified version of Archard’s Law, enhanced to reflect pressure-dependent wear behavior. Key components of the methodology include:
- Anisotropic material modeling based on fiber orientation predictions from injection molding simulations.
- Finite Element Analysis (FEA) to simulate gear meshing and contact pressure distribution.
- Hybrid wear factor modeling, integrating empirical data from D2D tests across various conditions.
Figure 2: Predicted fiber orientation in the gears (left) and the discs of the D2D (right) using injection molding simulation software (Moldflow)
Tests were conducted using Stanyl® PA46 reinforced with 30% and 60% glass fibers. Gear and D2D specimens were injection molded and tested under controlled thermal and mechanical conditions.
Both dry-running and greased configurations were evaluated, with wear quantified through gravimetric and geometric measurements.
Scope and Future Work
This work-in-progress lays the foundation for a comprehensive wear prediction model tailored to reinforced thermoplastics. The approach is designed to be adaptable to various gear configurations and operating
environments. Future research will expand the model’s applicability to lubricated systems and explore the long-term evolution of wear behavior under real-world conditions.
Additional details on the simulation and tests used to predict the wear performance of a fiber-reinforced plastic gear described in this article will be presented at the International Conference on High Performance Plastic Gears, Sept. 10-12, 2025.
Benjamin van Wissen is a CAE Expert at Envalior, a global supplier of high-performance thermoplastic solutions for a variety of applications and industries. With more than 15 years’ experience in finite element analysis with complex material models, he focuses on complex anisotropic structural mechanics simulation, with a specialization in polymer gears. He combines data obtained from testing, and is using insights obtained from FEA in order to improve the prediction capability and accuracy of thermoplastic gears. Benjamin joined Envalior in 2015 and earned a master's degree in mechanical engineering with a specialization in polymer mechanics from the Eindhoven University of Technology in Eindhoven Netherlands.