In the textbook by Wahl (1963, Mechanical Springs, 2nd ed., McGraw-Hill, New York, Chap. 20), he derived an equation predicting the diametral growth of a helical spring as the spring is compressed from free to solid height, and the spring's ends are free to rotate. A recent comparison with test data for growth of compression springs revealed that the calculated growth predicted by the Wahl formula did not agree well with measured values. Review of the Wahl derivation uncovered an arithmetic error that, when corrected, brought the calculated and measured diameters into closer agreement. The corrected diametral growth equation presented herein bounds the original data provided by Wahl, better matches an alternate growth equation derived by Ancker and Goodier for most springs evaluated, predicts larger growth than the original Wahl equation, and is a better fit to recent measured data.

References

References
1.
Wahl
,
A. M.
,
1963
,
Mechanical Springs
,
2nd ed.
,
McGraw-Hill
,
New York
, Chap. 20.
2.
Watanabe
,
K.
,
Yamamoto
,
H.
,
Ito
,
Y.
, and
Isobe
,
H.
,
2007
, “
Simplified Stress Calculation Method for Helical Spring
,”
Proceedings of Advanced Spring Technology JSSE (Japan Society of Spring Engineers) 60th Anniversary International Symposium
, Paper 4.
3.
Ancker
,
C. J.
, Jr.
, and
Goodier
,
J. N.
,
1958
, “
Pitch and Curvature Corrections for Helical Springs
,”
J. Appl. Mech.
,
25
(4), p.
468
.
4.
Wahl
,
A. M.
,
1953
, “
Diametral Expansion of Helical Compression Springs During Deflection
,”
J. Appl. Mech.
,
20
(4), pp.
565
566
.
5.
Love
,
A. E. H.
,
1944
,
A Treatise on the Mathematical Theory of Elasticity
,
4th ed.
,
Dover
,
New York
, pp.
414
415
.
6.
Wahl
,
A. M.
,
1959
, “
Pitch and Curvature Corrections for Helical Springs
,”
J. Appl. Mech.
,
26
(2), pp.
312
313
.
7.
Zubek
,
L.
, ed.,
2007
,
SMI Handbook of Spring Design
,
Spring Manufacturers Institute
,
Oak Brook, IL
, p.
37
.
You do not currently have access to this content.