In a previous paper, popular stress concentration factor charts for shoulder filleted shafts in bending and tension were shown to be in error, and more accurate solutions were published. In this paper, improved stress concentration factor information is presented for torsional loading, based on detailed finite element analyses. The new solutions agree with previous design charts, but cover a wider range of geometries. A concise engineering equation is presented for the stress concentration factor and maximum equivalent stress under each of three loading modes, along with another equation that reveals the location of each maximum stress component in the fillet. It is shown that the maximum stress locations for bending and tension loading are approximately the same, but can differ significantly from the maximum torsional stress location. In those cases, sharp surface gradients can cause the maximum equivalent notch stress under combined bending/axial and torsional loading to be overestimated when computed based on the maximum stress concentration factors for each load component. An example is used to demonstrate how the surface strain gradient causes the placement and size of a strain gage to have a strong influence on strain measurements.

Issue Section:
Technical Papers
Keywords:
stress effects, bending, tensile strength, torsion, load distribution, numerical analysis
Topics:
Finite element analysis, Stress, Stress concentration, Torsion, Tension, Errors, Numerical analysis, Strain gages
1.
Peterson, R. E., 1953, Stress Concentration Design Factors, Wiley, New York.
2.
Peterson, R. E., 1974, Stress Concentration Factors, Wiley, New York.
3.
Peterson, R. E., 1997, Stress Concentration Design Factors, 2nd Ed., Wiley, New York.
4.
Shigley, J. E., and Mischke, C. R., 1989, Mechanical Engineering Design, 5th Ed., McGraw-Hill, New York.
5.
Norton, R. L., 2000, Machine Design—An Integrated Approach, 2nd Ed., Prentice Hall, Englewood Cliffs, NJ.
6.
Tipton
,
S. M.
,
Sorem
, Jr.,
J. R.
, and
Rolovic
,
R.
,
1996
, “
Updated Stress Concentration Factors for Filleted Shafts in Bending and Tension
,”
ASME J. Mech. Des.
,
118
, pp.
321
–
327
.
7.
Gooyer
,
L. E.
, and
Overbeeke
,
J. L.
,
1991
, “
The Stress Distributions in Shoulder Shafts under Axisymmetric Loading
,”
J. Strain Anal.
,
26
, No.
3
, pp.
181
–
184
.
8.
Smith, T. E., 1989, “Fatigue Life and Strain Analysis of Notched Mechanical Components,” MS thesis, The University of Tulsa, Tulsa, Oklahoma.
Copyright © 2001
 by ASME
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