SScchhoollaarrss'' MMiinnee Doctoral Dissertations Student Theses and Dissertations Summer 2017 TThheerrmmoommeecchhaanniiccaall ffaattiigguuee lliiffee iinnvveessttiiggaattiioonn ooff aann uullttrraa--llaarrggee mmiinniinngg dduummpp ttrruucckk ttiirree Wedam Nyaaba Follow this and additional works at: https://scholarsmine.mst.edu/doctoral_dissertations Part of the Mechanical Engineering Commons, and the Mining Engineering Commons DDeeppaarrttmmeenntt:: MMiinniinngg EEnnggiinneeeerriinngg RReeccoommmmeennddeedd CCiittaattiioonn Nyaaba, Wedam, "Thermomechanical fatigue life investigation of an ultra-large mining dump truck tire" (2017). Doctoral Dissertations. 2596. https://scholarsmine.mst.edu/doctoral_dissertations/2596 This thesis is brought to you by Scholars' Mine, a service of the Missouri S&T Library and Learning Resources. This work is protected by U. S. Copyright Law. Unauthorized use including reproduction for redistribution requires the permission of the copyright holder. For more information, please contact [email protected]. THERMOMECHANICAL FATIGUE LIFE INVESTIGATION OF AN ULTRA- LARGE MINING DUMP TRUCK TIRE by WEDAM NYAABA A DISSERTATION Presented to the Faculty of the Graduate School of the MISSOURI UNIVERSITY OF SCIENCE AND TECHNOLOGY In Partial Fulfillment of the Requirements for the Degree DOCTOR OF PHILOSOPHY in MINING ENGINEERING 2017 Approved Samuel Frimpong, Advisor Grzegorz Galecki Nassib Aouad Xiaoming He K. Chandrashekhera ii 2017 Wedam Nyaaba All Rights Reserved iii ABSTRACT The cost benefits associated with the use of heavy mining machinery in the surface mining industry has led to a surge in the production of ultra-large radial tires with rim diameters in excess of 35 in. These tires experience fatigue failures in operation. The use of reinforcing fillers and processing aids in tire compounds results in the formation of microstructural inhomogeneity in the compounds and may serve as sources of crack initiation in the tire. Abrasive material cutting is another source of cracks in tires used in mining applications. It suffices, then, to assume that every material plane in the tire consists of a crack precursor of some known size likely to nucleate under the tire’s duty cycle loads. This assumption eliminates the need for prior knowledge of the location and geometry of crack features to be explicitly included in a tire finite element model, overcoming the key limitations of previous approaches. In this study, a rainflow counting algorithm is used to consistently count strain reversals present in the complex multiaxial variable amplitude duty-cycle loads of the tire to assess fatigue damage on its material planes. A critical plane analysis method is then used to account for the non-proportional loading on the tire material planes in order to identify the plane with the highest fatigue damage. The size of the investigated tire is 56/80R63, and it is typically fitted to ultra-class trucks with payload capacities in excess of 325 tonne (360 short ton). Experimental data obtained from extracted specimens of the tire were used to characterize the stress-strain and fatigue behavior of the tire finite element model in ABAQUS. A sequentially coupled thermomechanical rolling analysis of the tire provided stress, strains, and temperature data for the computation of the tire’s component fatigue performance in the rubber fatigue solver ENDURICA CL. The belt endings (tire shoulder), lower sidewall, and tread lug corners are susceptible to crack initiation and subsequent failure due to high stresses. This pioneering research effort contributes to the body of knowledge in tire durability issues in relation to mining applications. In addition, it provides a basis for off- road tire compounders and developers to design durable tires to minimize tire operating costs in the mining industry. iv ACKNOWLEDGMENTS I am highly indebted to my Lord and savior Jesus Christ, who by His abundant grace and love I am where I am today. A special thanks goes to my research advisor, Dr. Samuel Frimpong, whose unrelented support and guidance has brought about this success. I am grateful to my research committee members, Dr. Xiaoming He, Dr. K. Chandrashekhara, Dr. Grzegorz Galecki, and Dr. Nassib Aouad, for their inconceivable patience and advice. I could not have made it without their invaluable expertise. My deepest thanks go to my parents, Mr. Sakazele Nyaaba and Mrs. Mary Nyaaba, for investing in my education. Although you both did not get any formal education, you endeavored to give me one. Thank you! I also thank my siblings (Joseph, Alagnona, Comfort, and Grace) for the love shared with me during my study away from home. I am also grateful to all my friends, especially Ms. Maame Yaa Gyimah, Ms. Elsie Assan, Ms. Emelia Yeboah, Ms. Jennifer Gbadam, Ms. Carol Hudler, and Ms. Mavis Tetteh for their motivation and support. I am indepted to the Rolla First Assembly of God Church (and All Nations Christian Fellowship) for creating a home away from home for me during my stay in Rolla. Special thanks to the Missouri University of Science and Technology (Missouri S&T) Mining Engineering program staff: Mrs. Shirley Hall, Mrs. Tina Alobaidan, and Mrs. Judy Russell for their precious help during my stay in the department. I appreciate the help of the Missouri S&T IT Research Support Services for granting me access to use the university’s high-performance cluster computing system. I also thank the Technical Editor, Ms. Emily Seals, for her editorial services. I am grateful to the Department of Mining and Nuclear Engineering at Missouri S&T for the funding support from the Saudi Mining Polytechnic Program. I also appreciate the testing services provided by Axel Products Inc. Finally, I am indebted to Dr. William V. Mars and Jesse Suter of Endurica LLC for the software sponsorship, technical support and direction they freely offered me throughout this study. Their contribution and critique were very helpful in completing the research study. v TABLE OF CONTENTS Page ABSTRACT ....................................................................................................................... iii ACKNOWLEDGMENTS ................................................................................................. iv LIST OF ILLUSTRATIONS ............................................................................................. ix LIST OF TABLES ........................................................................................................... xiii NOMENCLATURE ........................................................................................................ xiv SECTION 1. INTRODUCTION ...................................................................................................... 1 1.1. BACKGROUND OF RESEARCH PROBLEM ................................................ 1 1.2. STATEMENT OF THE RESEARCH PROBLEM ............................................ 3 1.3. OBJECTIVES AND SCOPE OF STUDY ......................................................... 6 1.4. RESEARCH METHODOLOGY........................................................................ 7 1.5. SCIENTIFIC AND INDUSTRIAL CONTRIBUTIONS ................................... 8 1.6. RESEARCH PHILOSOPHY .............................................................................. 9 1.6.1. How Tires Are Made. ............................................................................. 10 1.6.1.1 Mixing. ........................................................................................10 1.6.1.2 Calendering. ................................................................................10 1.6.1.3 Extrusion. ....................................................................................11 1.6.1.4 Vulcanization. .............................................................................11 1.6.2. The 56/80R63 Tire Construction and Service Demand. ........................ 12 1.6.3. Thermomechanical Fatigue Problem. ..................................................... 13 1.6.4. Analytical Philosophy and Solution Procedures. ................................... 14 1.7. STRUCTURE OF DISSERTATION ............................................................... 16 2. LITERATURE REVIEW ......................................................................................... 17 2.1. STRUCTURE OF A PNEUMATIC TIRE ....................................................... 17 2.1.1. Bias-ply Tires. ........................................................................................ 19 2.1.2. Radial Tires. ........................................................................................... 19 2.1.3. Tire Materials. ........................................................................................ 20 2.1.3.1 Reinforcing particles. ..................................................................20 2.1.3.2 Reinforcing cords. .......................................................................20 vi 2.1.3.3 Rubber. ........................................................................................22 2.1.4. Tire Forces and Moments. ...................................................................... 24 2.2. HEAT GENERATION IN TIRES .................................................................... 25 2.2.1. Measurement of Viscoelastic Properties. ............................................... 26 2.2.2. Heat Generation and Temperature Rise Prediction. ............................... 32 2.3. TIRE FATIGUE STUDIES .............................................................................. 38 2.3.1. Continuum Mechanics Approach. .......................................................... 39 2.3.2. Fracture Mechanics Approach. ............................................................... 43 2.4. TIRE WEAR ..................................................................................................... 50 2.5. RATIONALE FOR PHD RESEARCH ............................................................ 51 2.6. SUMMARY ...................................................................................................... 54 3. TIRE THERMOMECHANICS ................................................................................ 57 3.1. TIRE THERMOMECHANICAL PROBLEM ................................................. 57 3.2. THERMAL SUBPROBLEM............................................................................ 58 3.2.1. Weak Formulation of the Thermal Subproblem. .................................... 60 3.2.2. Finite Element Discretization of the Thermal Subproblem. ................... 61 3.2.3. Boundary Treatment of the Thermal Subproblem. ................................ 63 3.3. MECHANICAL SUBPROBLEM .................................................................... 65 3.3.1. Weak Formulation of the Mechanical Subproblem. .............................. 67 3.3.2. Finite Element Discretization of the Mechanical Subproblem. ............. 69 3.3.3. Boundary Treatment of the Mechanical Subproblem. ........................... 75 3.4. SUMMARY ...................................................................................................... 77 4. NUMERICAL SOLUTION SCHEMES FOR TIRE THERMOMECHANICAL PROBLEM ............................................................................................................... 78 4.1. FULL DISCRETIZATION OF THE THERMAL SUBPROBLEM ................ 78 4.2. FULL DISCRETIZATION OF THE MECHANICAL SUBPROBLEM ........ 79 4.3. ERROR ESTIMATES FOR THE FINITE ELEMENT METHOD ................. 80 4.3.1. Convergence Rate Estimates of Thermomechanical FE Method. .......... 81 4.3.2. Realistic Simulation using the FE Package. ........................................... 84 4.4. SUMMARY ...................................................................................................... 85 5. TIRE MATERIAL, GEOMETRY, AND THERMOMECHANICAL FATIGUE MODELING ............................................................................................................. 89 vii 5.1. TIRE MATERIAL CHARACTERIZATION................................................... 89 5.1.1. Rubber Material Hyperelasticity. ........................................................... 89 5.1.2. Rubber Material Viscoelasticity. ............................................................ 95 5.1.3. Rubber Material Fatigue Behavior. ...................................................... 110 5.1.3.1 Fully relaxing crack growth test. ..............................................111 5.1.3.2 Non-relaxing crack growth test. ................................................113 5.1.4. Thermal Material Properties. ................................................................ 118 5.2. THE 56/80R63 TIRE GEOMETRY MODELING IN ABAQUS .................. 120 5.3. TIRE THERMOMECHANICAL FATIGUE MODELING AND ANALYSIS .................................................................................................... 125 5.3.1. Deformation Module. ........................................................................... 126 5.3.2. Thermal Module. .................................................................................. 126 5.3.3. Fatigue Module. .................................................................................... 127 5.3.3.1 Multiaxial fatigue life estimation. .............................................127 5.3.3.2 Rainflow counting procedure. ...................................................130 5.3.3.3 Initial crack size calibration. .....................................................132 5.3.3.4 Critical plane analysis. ..............................................................132 5.4. SUMMARY .................................................................................................... 134 6. MODEL VALIDATION, EXPERIMENTAL DESIGN, AND EXPERIMENTATION .......................................................................................... 136 6.1. MESH CONVERGENCE STUDY ................................................................ 136 6.2. VERTICAL STIFFNESS VALIDATION ...................................................... 137 6.2.1. Field Measurement. .............................................................................. 137 6.2.2. Static Vertical Stiffness Analysis. ........................................................ 139 6.3. FOOTPRINT VALIDATION ......................................................................... 139 6.4. DESIGN OF EXPERIMENTS ....................................................................... 141 6.5. EXPERIMENTATION OF TIRE OPERATING VARIABLES .................... 145 6.5.1. Simulating the Effects of Inflation Pressure on Fatigue Life. .............. 145 6.5.2. Simulating the Effects of Axle Load on Fatigue Life. ......................... 146 6.5.3. Simulating the Effects of Speed on Fatigue Life. ................................ 146 6.6. SUMMARY .................................................................................................... 146 7. RESULTS AND DISCUSSIONS .......................................................................... 148 viii 7.1. TIRE DEFLECTION, FORCES, AND CONTACT PRESSURE ................. 148 7.2. TIRE ENERGY LOSS AND TEMPERATURE ............................................ 156 7.3. TIRE FATIGUE PERFORMANCE ............................................................... 164 7.3.1. Local Cracking Plane Loading Histories. ............................................. 164 7.3.2. Effect of SIC on Fatigue Life. .............................................................. 169 7.3.3. Effect of Thermal Loads on Fatigue Life. ............................................ 175 7.4. SUMMARY .................................................................................................... 179 8. SUMMARY, CONCLUSIONS, AND RECOMMENDATIONS ......................... 183 8.1. SUMMARY .................................................................................................... 183 8.2. CONCLUSIONS............................................................................................. 184 8.3. PHD RESEARCH CONTRIBUTIONS ......................................................... 187 8.4. RECOMMENDATION .................................................................................. 187 APPENDIX ......................................................................................................................189 BIBLIOGRAPHY ........................................................................................................... 192 VITA .............................................................................................................................. 203 ix LIST OF ILLUSTRATIONS Figure Page 1.1. U.S. Percent Share of World Nonfuel Mineral Production ......................................... 2 1.2. Average Price of a 40.00R57 Tire [4] .......................................................................... 3 1.3. Mechanical Separation in a 55/80R63 Tire [10] .......................................................... 5 1.4. Fatigue failure Forms Initiated by Rock Cuts in (a) Sidewall, and (b) Tread ............. 6 1.5. Tire Aspect Ratio ....................................................................................................... 13 2.1. Schematic of a Radial Tire Cross Section.................................................................. 18 2.2. Bias-ply and Radial Tire Constructions [25] ............................................................. 19 2.3. A Steel Cord Composition [37] ................................................................................. 22 2.4. Mullins Effect in Filled Rubber ................................................................................. 24 2.5. Tire Forces and Moments [21] ................................................................................... 25 3.1. Thermal Boundary Surfaces on Tire Geometry ......................................................... 64 4.1. Tire Axisymmetric Mesh ........................................................................................... 86 4.2. Temperature (in ℃) Solution of (a) Developed Thermal FE Model Package, (b) MATLAB PDE Toolbox Solver, and (c) ABAQUS Thermal Analysis ................... 87 4.3. Displacement (in mm) Solution of Developed FE Model Package ........................... 88 4.4. Displacement (in mm) Solution of ABAQUS Coupled Temperature- Displacement Analysis ............................................................................................... 88 5.1. Regions of Extracted Tire Specimens ........................................................................ 90 5.2. Skived 56/80R63 Tire Specimens .............................................................................. 91 5.3. A Typical Simple Tension Specimen Geometry ....................................................... 93 5.4. Simple Tension Test Results–All Compounds .......................................................... 96 5.5. Derived Planar Tension Results–All Compounds ..................................................... 97 5.6. Derived Equibiaxial Tension Results–All Compounds ............................................. 98 5.7. Comparison of Test and Ogden Model Results–All Compounds and Modes ........... 99 5.8. Stress Relaxation Test Results–All Compounds ..................................................... 101 5.9. ABAQUS Prony Series Fitting Results–All Compounds ........................................ 104 5.10. Nonlinear Viscoelastic Model [15] ........................................................................ 105 5.11. Unit Cube Model Boundary Conditions ................................................................ 109
Description: