Water hammer is defined as a sudden increase in pipe pressure, which results in pressure waves that travel along the pipe at sonic velocities. In the wake of the pressure wave, dynamic stresses are created in the pipe wall, which contribute to pipe failures. A finite element analysis computer program was used to determine the three-dimensional dynamic stresses that result from pipe wall vibration at a distance from the end of a pipe, during a water-hammer event. The analysis was used to model a moving shock wave in a pipe, using a step pressure wave. Both aluminum and steel were modeled for an 8 NPS pipe, using ABAQUS®. For either material, the maximum stress was seen to be equal when damping was neglected. At the time the maximum stress occurred, the hoop stress was equivalent to twice the stress that would be expected if an equivalent static stress was applied to the inner wall of the pipe. Also, the radial stress doubled the magnitude of the applied pressure.

1.
Wiley
,
E. B.
, and
Streeter
,
V. L.
, 1993,
Fluid Transients
,
Prentice-Hall
, Upper Saddle River, NJ, pp.
1
105
.
2.
Thomson
,
W. T.
, 1993,
Theory of Vibration With Applications
,
Prentice Hall
, Englewood Cliffs, NJ, pp.
1
192
.
3.
Adachi
,
T.
,
Ujihashi
,
S.
, and
Matsumoto
,
H.
, 1991, “
Impulsive Responses of a Circular Cylindrical Shell Subjected to Water Hammer Waves
,”
ASME J. Pressure Vessel Technol.
0094-9930,
113/517
, pp.
517
523
.
4.
Joukowski
,
N.
, 1904, “
Water Hammer
,”
Proceedings American Water Works Association
,
American Water Works Association
, Denver, CO, Vol.
24
, pp
341
424
.
5.
Green
,
D. J.
, 1993,
Technical Evaluation: 300 Area Steam Line Valve Accident
,
Westinghouse
, Hanford, pp.
1
-1–11-
3
.
6.
Leishear
,
R. A.
, 2002, “
Dynamic Pipe Stresses During Water Hammer—I. A Finite Element Approach
,”
Proc. of Design and Analysis of Piping, Vessels, and Components
,
ASME
, New York, Vol.
440
, pp.
113
121
.
7.
Leishear
,
R. A.
, 2002, “
Dynamic Pipe Stresses During Water Hammer—II. A Vibration Analysis
,”
Proc. of Design and Analysis of Piping, Vessels, and Components
,
ASME
, New York, Vol.
440
, pp.
128
136
.
8.
Leishear
,
R. A.
, 2002, “
Dynamic Pipe Stresses During Water Hammer—III. Complex Stresses
,”
Proc. of Design and Analysis of Piping, Vessels, and Components
,
ASME
, New York, Vol.
440
, pp.
143
152
.
9.
Leishear
,
R. A.
, and
Morehouse
,
J. H.
, 2003, “
Dynamic Pipe Stresses During Water Hammer, IV, A Vibration Analysis
,” Second Annual Water Hammer Conference, ASME-JSME Joint Fluids Engineering Conference.
10.
Collins
,
J. A.
, 1993,
Failure of Materials
,
Wiley
, New York, pp.
144
245
.
11.
Leishear
,
R. A.
, and
Morehouse
,
J. H.
, 2003, “
Dynamic Pipe Stresses During Water Hammer, V, Applications
,” 2003,
Forum on Fluid Transients
, International Mechanical Engineering Congress and Exposition,
ASME
, New York, pp.
1
9
.
12.
Leishear
,
R. A.
, and
Rhodes
,
C. A.
, 2001, “
Maximum Pipe Stresses Resulting From a Water Hammer Induced Shock Wave: A Comparison of Finite Element to Vibration Analysis Techniques
,” Master’s thesis, University of South Carolina, pp.
1
29
.
13.
Kolsky
,
H.
, 1963,
Stress Waves in Solids
,
Dover
, New York, pp.
1
84
.
14.
Roark
,
R. J.
, and
Young
,
W. C.
, 1975,
Roark’s Formulas for Stress and Strain
,
McGraw-Hill
, New York, pp.
448
504
.
15.
Weybrant
,
E.
, 2000, Memo to R. A. Leishear, “
VDLOAD
,” Hibbit, Karlsson, and Sorensen, Inc., Rhode Island.
16.
Leishear
,
R. A.
, 2005, Ph.D. dissertation, “
Dynamic Stresses During Structural Impacts and Water Hammer
,” University of South Carolina, Columbia, pp.
61
119
.
17.
Williams
,
D. K.
, and
Ranson
,
W. F.
, 1997, “
Pipe Anchor Discontinuity Analysis: Axisymmetric Closed Form Solutions Utilizing Bessel’s Functions & Fourier Series
,”
Approximate Methods in the Design and Analysis of Pressure Vessels and Piping Components
,
ASME
, New York, Vol.
347
.
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