Laboratory Manual Of Testing Materials

LABORATORY MANUAL TESTING MATERIALS -- 1913 -- PREFACE - This manual is the outcome of the operation, through eighteen years, of the Laboratory for Testing Materials of Purdue University. During this time several instructors, temporarily serving the laboratory, have improved its practice. Especial mention should be . made of the services of the late Professor Hancock, whose untimely death deprived the science of testing materials of a very able and patient investigator, and his colleagues of a good friend. Professor Yeoman, now of Valparaiso University, did valuable service in the organization of the work of the cement laboratory. The authors are indebted to Professor Poorman of Purdue University, for valuable suggestions. In its original form the manual was published by the senior author of this volume and later, with the assistance of Professor Scofield, the manual was enlarged, and was found useful in several universities. Now the authors have availed themselves of the assistance of the present publishers to enlarge the work. The list of experiments has been increased, and a more complete treatment of machines and apparatus added. One purpose of the manual is to relieve the instructoc from the necessity of explaining the details of mechanical procedure, and so to free his time for Aatters of greater educational importance. It is also hoped by the authors that the practitioner mill find the volume of convenient use. LAFAYETTE, IND., August, 1913, CONTENTS PAGE PREFACE .................... C . . V CHAPTER I.-GENERAL. ............... 1 CHAPTER 11.-GENERAL INSTRUCTIONS ......... 4 Instructions for Writing Reports ......., . .. 6 CHAPTER 111.-DEFINITIONS ............. 9 Stress...................... 9 Elasticity .................... 11 Resilience .................... 13 CHAPTER 1V.-MATERIALS STRESSED BEYOND THE ELASTIC LIMIT ...................... 15 Fractures under Tension ............... 15 Fractures under Compression ...... ..... 16 Fractures under Shear ............... 17 . CHAPTER V.-TESTING AND TESTING MACHINES ...., 19 Technical Qualities of Materials .. . ..... . f . . 19 Testing Machines .................. 20 a Holding the Specimen ........... 20 b Method of Applying Lead ......... 26 c Weighing Mechanisms ........... 34 Extensometers and Other Deformation Instruments . . 35 ......... 41 Experiments for Advanced Work .......... 43 CHAPTER VI1.-INSTRUCTIONS FOR PERFORMING EXPERI- CHAPTER V1.-LIST OF EXPERIMENTS MENTS ..................... 45 Article I . Testing Machines ............ 45 A.1 . Study of Testing Machines . ........ 45 A.2 . Calibration of Testing Machines ...... 47 A.3 . Calibration of Extensometers ....... 48 Article I1 . Iron and Steel ............. 49 B.1 . Tension Test of Iron and Steel . ...... 49 B.2 . Tension Test of Cast Iron or Steel Castings . 51 B.3 . Autographic Tension Test of Iron or Steel . . 51 B4 . Tension Test with Extensometer ....... 5 B.5 . Experiment in Torsion . .......... 54 B.6 . Test of Wired Cable . ........... 56 B.7 . compession of Helical Spring ....... 57 vii .L S.. V111 CONTENTS B-8. Effect of Overstrain on Yield Point of Steel . B-9. Flexure Test of Cast Iron or Steel.- . . . . . B-10. Flexure Test of Brake Beam . . . . . . . . B-l l. Vibration Test of Staybolt Iron . . . . . . Article 111. Test of Wood. . . . . . . . . ., . . . C-l. Instructions for aborator Exercise for the Identification of Woods . . .. . . . . . . C-2. Compresion of Short Wood Blocks Parallel to Grain . . . . . . . . . . . ...