Application of Web-Based Bar Fatigue Database Database Development Thomas G. Oakwood
Bar Steel Fatigue Database- Objectives Develop a strain-controlled fatigue database for carbon and low alloy bar steels for the automotive and OEM industries Provide fatigue data which can be used to predict and analyze service life for chassis, engine and drive train components Utilize a directly accessible Internet-based format
Bar Steel Fatigue Database- Participants AISI Bar Steel Producers Automotive Manufacturers OEM Suppliers Two Universities University of Toledo University of Waterloo
Bar Steel Fatigue Database- Information Steel Characterization Composition Processing History Microstructure Mechanical and Cyclic Properties Tabulation of Axial Fatigue Data Graphical Output of Monotonic and Cyclic Stress-Strain Curves and Strain-Life Curves
Bar Steel Fatigue Database-Format Direct-Access Internet Format Multiple Screens Master Index Tabbed Material Properties Screens Report Format Excel SAE Independent Access for Microstructures and Graphs Comparative Printing
Iteration Number 18 SAE Steel Grade 1038 Process Normalized 1650 Steel Making Practice Bar Steel Fatigue Database- Sample Data Basic Oxygen Electric Furnace Vacuum Degas Ladle Refined Yes No No Yes Casting Practice Ingot Cast Continuous Cast No Yes Billet Size (mm) Bloom Size (mm) 300 X 600
Bar Steel Fatigue Database- Sample Data Chemical Properties Carbon, % 0.40 Manganese, % 0.8 Phosphorous, % 0.013 Sulfur, % 0.024 Silicon, % 0.28 Copper, % 0.03 Nickel, % 0.01 Chromium, % 0.04 Molybdenum, % 0.01 Vanadium, % 0.00 Niobium, % 0.00 Aluminum, % 0.03
Monotonic Properties Bar Steel Fatigue Database- Sample Data Modulus of Elasticity, E, GPa 201 Yield Strength, YS, MPa 330.7 Upper Yield Strength, UYS, Mpa 346.8 Lower Yield Strength, LYS, Mpa 327.2 Yield Point Elongation, YPE % 1.10 Ultimate Strength, UTS, MPa 582.2 Percent Elongation, %EL, 44 Percent Reduction in Area, %RA 54 Strength Coefficient, K, MPa 1,105.7 Strain Hardening Exponent, n 0.260 True Fracture Strength, σ f, Mpa* 898 *Corrected for Necking True Fracture Ductility, ε f, % 80.0
Bar Steel Fatigue Database- Sample Data Cyclic Properties Cyclic Yield Strength, YS', MPa 342 Fatigue Strength Coefficient, σ f ', MPa 1,039 Fatigue Strength Exponent, b -0.1062 Fatigue Ductility Coefficient, ε f ' 0.303 Fatigue Ductility Exponent, c -0.4794 Cyclic Strength Coefficient, K', MPa 1,340 Cyclic Strain Hardening Exponent, n' 0.2198 Fatigue Strength @ 10 6 Cycles, MPa 222.6
Bar Steel Fatigue Database-Access Private Access AISI Bar Steel Fatigue Committee Subscribers Private Access to Data for Two Years 71 Iterations (26 More in Progress) Public Access General Public Data Available After Two Year Restriction 43 Iterations Available User Name and Password Required
Application of Web-Based Bar Fatigue Database Database Application Yung - Li Lee DaimlerChrysler
MODERN FATIGUE DESIGN PROCESS Component/vehicle design CAE models Prototypes build up Field data acquisition Virtual proving grounds Loads database CAE analysis ok no Data analysis & reduction Load-based fatigue analysis Fatigue testing no ok Sign off
FATIGUE EVALUATION METHOD Test drive - proving grounds System test rig -simulators & dynamometers Life Test Component test rig - constant & block cycle tests Loads Load-life or nominal stress life methods Local strain life approach Life Cal.
ROAD TEST SIMULATOR
STRESS COATING FOR STRESS RAISERS
GAGING/WIRING A TRANS CASE
GAGED TRANS CASE IN-VEHICLE CONDITION
GAGING/WIRING A CHANKSHAFT
GAGED JOUNCE BUMPER
GAGED SPRING
INSTRUMENTED SPRING AND JOUNCE BUMPER
GAGED SHOCK
INSTRUMENTED SHOCK, SPRING AND JOUNCE BUMPER
FATIGUE ANALYSIS OF A WELDED CRADLE F 1 = Channel 1 WELD Database Results Damage Values Endurance Safety Factors Fatigue Life Time Channel 2 F 2 = FATIGUE ANALYSIS Channel n Specimen Material Data F n =
FATIGUE ANALYSIS OF A CYLINDER HEAD
Synchronized Kinematic Animation (Courtesy LMS North America)
Stress Animation (Courtesy LMS North America)