Fatigue Life Simulation of a High Pressure Breech System


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In order to evaluate the structural integrity of the breech system used for a thick-walled cylinder subjected to pulsating high internal pressure, fatigue life simulation of a breech system was performed. A stress analysis of the breech was performed to locate the critical region vulnerable to crack initiation. Low-cycle fatigue behavior of the breech material was investigated to obtain the fatigue crack initiation properties. Elastic-plastic finite element stress analysis resulted in a stress concentration at the breech ring groove root. Strains at the breech ring and block were experimentally measured using strain gages and resulted in similar values compared to the calculated strains. Local strain approach was employed to estimate the fatigue life of the breech system for crack initiation at the groove root of the breech ring. Fatigue tests using simulation specimens were performed and an averaged fatigue life was obtained, showing a very good agreement with the calculated fatigue life within a factor of two.



Key Engineering Materials (Volumes 326-328)

Edited by:

Soon-Bok Lee and Yun-Jae Kim




S. K. Koh et al., "Fatigue Life Simulation of a High Pressure Breech System", Key Engineering Materials, Vols. 326-328, pp. 1027-1030, 2006

Online since:

December 2006




[1] J.H. Underwood and E. Troiano: J. Pressure Vessel Technology Vol. 125(2003), p.287.

[2] S.K. Koh: Int. J. Fatigue Vol. 18(1996), p.49.

[3] ABAQUS Analysis User's Manual (ABAQUS Inc., USA 2003).

[4] Annual Book of ASTM Standards, ASTM E606 Vol. 03. 01 (ASTM, USA 2001). � � Fig. 6 Load vs. cycles to failure of the breech simulation fatigue test.

[10] [4] [10] [5] [10] [4] [10] [5] Predicted life, Npred(cycles) Experimental life, Nf(cycles) Fig. 7 Comparison of experimental and predicted fatigue lives for breech system �.

[10] [4] [10] [5] [30] [40] [50] [60] [70] [80] [90] 100 Simulation load, Fmax (kN) Cycles to 2. 0mm crack length, Nf.