Session: 06-04: Performance Systems Modeling and Design

Paper Number: 164649

164649 - Dynamic Stress Analysis of Piston Rings in a Four-Stroke Cycle Engine 

Abstract: 

This study enhances the CASE (Cylinder Kit Analysis System for Engines) three-dimensional structural dynamics piston ring model by incorporating dynamic stress calculations over an engine cycle. Previous work analyzed piston ring deformations, capturing axial, twist, and radial behaviors under dynamic loading. However, stress analysis—critical for identifying failure points and assessing durability—was previously lacking. To address this, an approach incorporating the stiffness matrix was implemented to compute three-dimensional dynamic stresses throughout the engine cycle. Using straight beam elements, the model determines piston ring motion and the corresponding stress state. The static stress resulting from ring tension after installation within the engine cylinder was validated against an Abaqus 3D solid element model, where the two models showed strong alignment. Next, the CASE model was used to simulate 3D dynamic stresses considering inter-ring gas pressure, contact forces, inertia loads, and internal forces resulting from ring-liner conformance. Dynamic ring stresses are presented at several crank angles. The results highlight the model’s capability to assess dynamic loading effects throughout the cycle. This study also looks at the effect of bore distortion on the piston ring stress, with results suggesting the ring experiences lower stress after accounting for the expansion of the engine cylinder. This advancement provides a foundation for future studies on wear and fatigue, improving piston ring durability assessment across multiple cycles and loading conditions.

Presenting Author: Fawaz Imtiaz Michigan State University

Presenting Author Biography: The presenter, Fawaz Imtiaz is a Graduate Research Assistant under Dr.Harold Schock's supervision. He is doing his PhD in Mechanical Engineering at Michigan State University. His main research field includes Internal Combustion Engine performance analysis, piston design and analysis, Modeling and Numerical Analysis of engines.

Authors:

Fawaz Imtiaz Michigan State University
Daniel Nicklowitz Michigan State University
Harold Schock Michigan State University
Scott Baeder Mid-Michigan Research
Sadiyah Sabah Chowdhury Cummins Inc.
Dan Richardson Cummins Inc.
Callen Schmalz Cummins Inc.