TABLE OF CONTENTS Charles R. Mischke, Ph.D., P.E.
Professor Emeritus of Mechanical Engineering
Iowa State University
Ames, Iowa
Joseph E. Shigley
Professor Emeritus
The University of Michigan
Ann Arbor, Michigan
| a | Crack semilength | |
| A | Area | |
| D, d | Diameter | |
| F | Force or load | |
| I | Second moment of area | |
| J | Second polar moment of area | |
| K | Stress-intensity factor | |
| K ? | Stress-concentration factor for static loading | |
| K c | Critical-stress-intensity factor | |
| K t | Normal-stress-concentration factor | |
| K ts | Shear-stress-concentration factor | |
| M | Moment | |
| n | Design factor | |
| q s | Sensitivity index | |
| r | Radius or ratio | |
| S sy | Yield strength in shear | |
| S uc | Ultimate compressive strength | |
| S ut | Ultimate tensile strength | |
| S y | Yield strength | |
| ? | Factor of safety | |
| ? | Normal stress | |
| ?? | von Mises stress | |
| ? | Shear stress | |
| ? o | Octahedral shear stress or nominal shear stress |
The discovery of the relationship between stress and strain during elastic and plastic deformation allows interpretation either as a stress problem or as a strain problem. Imposed conditions on machine elements are more often loads than deformations, and so the usual focus is on stress rather than strain. Consequently, when durability under static conditions is addressed, attention to permissible stress is more common than...
