Fatigue Tests of Curved Plate Girder Assemblies
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TE 662 .A3 )rt No. FHWA-RD-79-133 no. FF T ' Rl 79 FATIGUE OF CURVED STEEL BRIDGE ELEMENTS Fatigue Tests of Curved Plate Girder Assemblies April 1980 Interim Report Diaphragm (typ) Girder 2 DEPARTMENT OF TRANSPORTATION JUL 1 1930 LIBRARY Girder Document is available to the public through the National Technical Information Service, Springfield, Virginia 22161 Prepared for FEDERAL HIGHWAY ADMINISTRATION SPATES O* Offices of Research & Development Structures & Applied Mechanics Division Washington, D.C. 20590 FOREWORD Horizontally curved steel plate and box girders are being used more frequently for highway structures, sometimes because of increased economy, and because of their esthetic appearance. The design of curved girders differs from that of straight gir- ders in that torsional effects, including nonuniform torsion, must be considered. The resulting use of lateral bracing between curved plate girders and internal bracing and stiffen- ing of curved box girders gives rise to complicated states of stress and to details which can be sensitive to repetitive loads. This situation prompted the FHWA to sponsor this research, the primary objective of which is to establish fatigue design guide- lines for curved girder highway bridges in the form of simplified equations or charts. This report is one in a series of eight on the results of the research and is being distributed to the Washington and field offices of the Federal Highway Administration, State highway agencies, and interested researchers. Charles F. Sc^e^Tey Director, Office of Research Federal Highway Administration NOTICE This document is disseminated under the sponsorship of the Department of Transportation in the interest of information exchange. The United States Government assumes no liability for its contents or use thereof. The contents of this report reflect the views of the contractor, who is responsible for the accuracy of the data presented herein. The contents do not necessarily reflect the official views or policy of the Department of Transportation. This report does not constitute a standard, specification, or regulation. The United States Government does not endorse products or manufacturers. Trade or manufacturers' names appear herein only because they are considered essential to the object of this document. Technical Report Documentation Page J*£l 1. Report No. 2. Government Accession No. , 3. Recipient's Cotolog No. FHWA-RD-79-133, 4. Title and Subtitle 5. Report Dote April 1980 FATIGUE OF CURVED STEEL BRIDGE ELEMENTS, - 6. Performing Code Fatigue Tests of Curved Plate Girder Assemblies Organizotion 8. Performing Orgonizotion Report No. 7. Author's) j_ Hart iey Daniels and W. C. Herbein Fritz Engineering Lab Report No. 398.3 9. Performing Organization Name and Address 10. Work Unit No. (TRAIS) 35F2-052 Fritz Engineering Laboratory, Bldg. #13 Lehigh University 11. Controct or Gront No. DOT-FH-11-8198 Bethlehem, Pa. 18015 13. Type of Report ond Period Covered 12. Sponsoring Agency Name and Address r- i Interim DEPARTMENT U.S. Department of Transportation j OF February 1976 - May 1977 M-. TRANSPORTATION federal Highway Administration, | 14. Sponsoring Agency Code Washington, D. C. 20590 S0970 JUL 1 1S6Q 15. Supplementary Notes FHWA Contract Manager LIBRARY Jerar Nishanian, HRS-11 16. Abstract Research on the fatigue behavior of horizontally curved, steel bridge ele- ments was conducted at Lehigh University under the sponsorship of the Federal Highway Administration (FHWA) of the U.S. Department of Transportation. The investigation is centered on the effect of welded details on curved girder fatigue strength. Fatigue tests of five full-scale curved plate girder assemblies are a part of the investigation. The fatigue behavior of five types of welded details from AASHTO Catego- ries C and E is monitored while undergoing two million constant amplitude load cycles on the assemblies. Primary fatigue cracking due to in-plane bending and torsion was observed as well as secondary fatigue cracking due to out-of-plane bending of the web. The web performance under fatigue loading was also observed. The observation of primary fatigue cracking at the welded details indi- cates that their fatigue behavior, on curved plate girders, is adequately described by the present AASHTO Category C and Category E design guidelines for straight girders. Groove-welded lateral attachments with circular transitions and secon- dary fatigue cracking of details at diaphragm locations are problem areas. The web performance demonstrated that allowable stress provisions for web slenderness ratios and transverse stiffener spacing are adequate in the AASHTO specifica- tions and overly stringent in CURT guidelines. 17. Key Words 18. Distribution Stotement Bridges (structures), fatigue, girder Document is available to the public bridges, structural engineering, through the National Technical Infor- testing, torsion, welding mation Service, Springfield, VA 22161 19. Security Classif. (of this report) 20. Security Classif. (of this page) 21- No. of Pages 22. Price Unclassified Unclassified 150 Form DOT F 1700.7 (8-72) ACKNOWLEDGMENTS The investigation reported herein was conducted at Fritz Engineering Laboratory, Lehigh University, Bethlehem, Pennsylvania. Dr. Lynn S. Beedle is the Director of Fritz Laboratory and Dr. David A. VanHorn is the Chairman of the Department of Civil Engineering. The work was a part of Fritz Laboratory Research Project 398, "Fatigue of Curved Steel Bridge Elements" sponsored by the Federal Highway Administra- tion (FHWA) of the United States Department of Transportation. The FHWA Project Manager is Mr. Jerar Nishanian. The Advisory Panel members are Mr. A. P. Cole, Dr. Charles G. Culver, Mr. Richard S. Fountain, Mr. Gerald Fox, Dr. Theodore V. Galambos, Mr. Andrew Lally, Mr. Frank D. Sears, and Dr. Ivan M. Viest. The following members of the faculty and staff of Lehigh University made major contributions in the conduct of this work: Dr. John W. Fisher, Dr. B. T. Yen, Dr. R. G. Slutter, Dr. N. Zettlemoyer, and R. P. Batcheler. Mr. Kenneth Harpel and Mr. Robert Dales assisted in executing the test program. Mrs. Mary Snyder and Ms. Shirley Matlock typed the manuscript. The figures were prepared by Mr. John Gera and his staff. Mr. R. N. Sopko provided the photographs. 11 TABLE OF CONTENTS Page 1. INTRODUCTION 1 1.1 Background 1 1.2 Objectives and Scope 2 2. DESIGN AND FABRICATION OF ASSEMBLIES 4 2.1 Analysis and Design of Assemblies 4 2.2 Design of Welded Details 7 2.3 Fabrication of Assemblies 12 3. ERECTION AND INSTRUMENTATION OF ASSEMBLIES 16 3.1 Erection 16 3.2 Instrumentation 27 4. INITIAL STATIC AND CYCLIC LOAD TESTS 49 4.1 Initial Static Tests 49 4.2 Initial Cyclic Tests 50 4.3 Group 2 Welded Detail Locations 73 4.4 Diaphragm and Lateral Bracing Members 74 5. FATIGUE TESTING 77 5.1 General Procedure 77 5.2 Crack Detection and Repair 77 6. RESULTS OF FATIGUE TESTS 81 6.1 Primary Fatigue Cracks 81 6.2 Secondary Fatigue Cracks 95 6.3 Web Performance 103 7. DISCUSSION OF TEST RESULTS 104 7.1 Detail Type I 104 7.2 Detail Type II 117 7.3 Detail Types III and III 118 ° a 7.4 Detail Type IV ° 120 o 7.4.1 Fatigue Life Prediction 121 7.4.2 Actual Flaws 125 7.4.3 Summary - Type IV Detail 126 o 7.5 Detail Type V 126 7.6 Detail Type V°j* 129 7.7 Web Fatigue Strength 130 iii 8. SUMMARY AND CONCLUSIONS 132 9. RECOMMENDATIONS FOR FURTHER WORK 134 10. REFERENCES 135 APPENDIX A STATEMENT OF WORK 138 APPENDIX B LIST OF REPORTS PRODUCED UNDER DOT- FH- 11-8198 142 APPENDIX C MATERIAL PROPERTIES 143 IV LIST OF ABBREVIATIONS AND SYMBOLS a = crack shape semi-minor axis b = crack shape semi-major axis b = flange width f d = transverse stiffener spacing r = radius of circular transition at end of groove-welded gusset plate t = flange thickness t = web thickness w D = web depth w L = span length measured at centerline of the test assembly L.. = span length measured at centerline of Girder 1 of the test assembly L_ = span length measured at centerline of Girder 2 of the test assembly N = number of load cycles R = horizontal radius of curvature of test assembly 5 = stress range° r o o III ,etc. = welded detail types/subtypes for open section (plate OH girder) test assemblies 6 = lateral web deflection a = yield stress y a = ultimate stress u V U.S. Customary-SI Conversion Factors To convert To Multiply by inches (in) millimeters (mm) 25.40 inches (in) centimeters (cm) 2.540 inches (in) meters (m) 0.0254 feet (ft) meters (m) 0.305 miles (miles) kilometers (km) 1.61 yards (yd) meters (m) 0.91 2 square inches (sq in) square centimeters (cm ) 6.45 2 square feet (sq ft) square meters (m ) 0.093 2 square yards (sq yd) square meters (m ) 0.836 2 acres (acre) square meters (m ) 4047 2 square miles (sq miles) square kilometers (km ) 2.59 2 cubic inches (cu in) cubic centimeters (cm ) 16.4 3 cubic feet (cu ft) cubic meters (m ) 0.028 3 cubic yards (cu yd) cubic meters (ra ) 0.765 pounds (lb) kilograms (kg) 0.453 tons (ton) kilograms (kg) 907.2 one pound force (Ibf) newtons (N) 4.45 one kilogram force (kgf) newtons (N) 9.81 pounds per square foot (psf) newtons per square 47.9 2 meter (N/m ) pounds per square inch (psi) kilonewtons per square 6.9 2 meter (kN/m ) 3 gallons (gal) cubic meters (m ) 0.0038 3 acre-feet (acre-ft) cubic meters (m ) 1233 gallons per minute (gal/min) cubic meters per minute (m3 /min) 0.0038 newtons per square pascals (Pa) 1.00 2 meter (N/m ) VI 1. INTRODUCTION 1. 1 Background The increased utilization of horizontally curved girders in highway bridges has prompted the initiation of several research pro- ' ' ' ' jects on curved girder bridges ' .