SUBJECT: Ph.D. Proposal Presentation
   
BY: Patrick Smyth
   
TIME: Monday, June 29, 2015, 9:00 a.m.
   
PLACE: MRDC Building, 4211
   
TITLE: A Finite Element Model for Poroviscoelastic Hydrodynamic Lubrication
   
COMMITTEE: Dr. Itzhak Green, Chair (ME)
Dr. Jeffrey Streator (ME)
Dr. Scott Bair (ME)
Dr. Robert L. Jackson (Auburn University- ME)
Dr. Michael Varenberg (ME)
 

SUMMARY

Triboelements are ubiquitous in modern society. They exist in countless applications from locomotion (both human and mechanical) to magnetic recording. Billions of dollars are lost from tribological inefficiencies per year, and at the same time, the state-of-the-art is pushing triboelements toward greater capabilities such as load support and longevity. Therefore, the application of tribological devices is an area of active research. A potential advancement comes from including a poroviscoelastic material in triboelements. It is hypothesized that poroviscoelasticity can improve triboelement properties such as stiffness, damping, and wear resistance without sacrificing significant load support. A poroviscoelastic material has multiple features that make it interesting for study: porous structure for lubricant storage, a built-in dissipation mechanism, and adaptive stiffness and damping characteristics. The current poroviscoelastic models are traditionally based on a Zener-type material structure; however, a novel model for viscoelasticity will be introduced. This model is based on fractional calculus that simplifies the description of viscoelasticity while retaining model robustness. The fractional calculus poroviscoelastic model will be implemented in Abaqus, a commercially available finite element analysis (FEA) software. Abaqus allows for external interfacing, and broad application, of the poroviscoelastic model. These applications are numerous and include: mechanical seals, biomechanical joint replacements, flexible rotordynamic bearings, drill string lubricant seepage analysis, and biomimetic dampers, among others. The proposed constitutive material model will be coupled with a hydrodynamic bearing. This work will serve as the theoretical foundation for the study of poroviscoelastic hydrodynamic lubrication and its applications.