Abstract
Effect of tensile overload on elevated temperature crack growth behavior during the subsequent load hold period has been studied by numerical and experimental methods. Finite element analysis of compact specimens shows that when the tensile overload precedes the load hold period, C t during the hold period is significantly smaller (i.e. retarded) compared to the case without the overload. This is due to crack tip stress relaxation associated with large crack tip plasticity generated by the overload. A modified C t estimation scheme is proposed by introducing a new equation for t pl. Using this scheme, the retardation behavior of C t due to the overload is successfully modeled.
Creep-fatigue crack growth data for an ex-service 1.25Cr-0.5Mo steel at 538°C (1000°F) were generated in air. The hold times are 10 seconds, 98 seconds and 10 minutes. Time-dependent crack growth rate during the load hold period, (da/dt)avg, is correlated with (C t )avg estimated by the new estimation scheme. (da/dt)avg data from all the tests with overload are higher than those from the tests without overload. The peak stress associated with the overload seems to have enhanced void nucleation and to incrase the time-dependent crack growth rate due to creep. This argument is supported by microscopic observations.
Similar content being viewed by others
References
B.W. Roberts, F.V. Ellis and R. Viswanathan, in Proceedings of the American Power Conference, Chicago, IL 22–24 April 1985, 295–301.
G.H. Harth, Power Engineering 92(4) (1988) 56–58.
A. Saxena, R.S. Williams and T.T. Shih, in Fracture Mechanics: Thirteenth Conference, ASTM STP 743 (1981) 86–99.
A. Saxena, in Thermal and Environmental Effects in Fatigue: Research Design Interface-PVP Vol. 71, C.E. Jaske et al. (eds.), The American Society of Mechanical Engineers (1981) 171–184.
A. Saxena and B. Gieseke, in Proceedings of MECAMAT-International Seminar on High Temperature Fracture, Mechanisms and Mechanics, Dourdan, October 1987, Vol. III, 19–36.
K. Ohji and S. Kubo, in High Temperature Creep-Fatigue, Elsevier Applied Science, Current Japanese Materials Research, Vol. 3 (1988) 91–113.
K. Ohji, in Role of Fracture Mechanics in Modern Technology, Elsevier Science Publishers B. V. (1987) 131–144.
K.M. Nikbin and G.A. Webster, in Low Cycle Fatigue, H.D. Solomon et al. (ed), ASTM STP 942 (1988) 281–292.
T. Weerasooriya and T. Nicholas, in Fracture Mechanics: Eighteenth Symposium, ASTM STP 945 (1988) 181–191.
K.B. Yoon, A. Saxena and P.K. Liaw, International Journal of Fracture 59 (1993) 95–114.
C.P.Leung, D.L.McDowell and A.Saxena, International Journal of Fracture 36(4) (1988) 275–289.
K.B. Yoon, A. Saxena and D.L. McDowell, in Fracture Mechanics: Twenty Second Symposium, ASTM STP 1131 (1992) 367–392.
A. Saxena, in Fracture Mechanics: Seventeenth Volume, ASTM STP 905 (1986) 185–201.
J.L. Bassani, D.E. Hawk and A. Saxena, in Nonlinear Fracture Mechanics: Volume. I-Time Dependent Fracture, ASTM STP 995 (1986) 7–26.
A. Saxena, H. Ernst and J.D. Landes, International Journal of Fracture 23 (1983) 245–257.
H. Riedel and J.R. Rice, in Fracture Mechanics: Twelfth Conference, ASTM STP 700 (1980) 112–130.
V. Kumar, M.D. German and C.F. Shih, An Engineering Approach to Elastic-Plastic Analysis. Technical Report EPRI NP-1931, Electric Power Research Institute (1981).
A. Saxena and J.D. Landes, in Advances in Fracture Research: ICF-6, Pergamon Press (1984) 3977–3988.
C.P. Leung, Estimation of The C t Parameter for Primary Creep. PhD thesis, the George W. Woodruff School of Mechanical Engineering, Georgia Institute of Technology, July 1988.
C.P. Leung and D.L. McDowell, Documentation of A Finite Element Program For Two Dimensional Elasticplastic-viscoplastic Deformations, Georgia Institute of Technology, School of Mechanical Engineering (1988).
D.L. McDowell, Journal of Applied Mechanics 52 (1985) 298–302.
D.R.J. Owen and E. Hinton, Finite Elements in Plasticity, Pineridge Press Limited (1980).
A. Saxena and P.K. Liaw, Remaining Life Estimation of Boiler Pressure Parts-Crack Growth Studies, Technical Report, Electric Power Research Institute, EPRI contract RP 2253–7 (1986).
A. Saxena and J. Han, Evaluation of Crack Tip Parameters for Characterizing Crack Growth Behavior in Creeping Material, Technical Report, Fracture and Fatigue Research Lab., Georgia Institute of Technology (1986), ASTM Task Group Report, Joint task group E24.08.07/E24.04.08.
ASTM Annual Books of Standards, Standard Test Method for Measurement of Fatigue Crack Growth Rates, ASTM Standard E647–88 (1988).
H. Riedel, in Elastic-Plastic Fracture: Second Symposium Volume. I-Inelastic Crack Analysis, ASTM STP 803 (1983) I/505–I/520.
R. Raj, Acta Metallurgica 26 (1978) 995–1006.
Author information
Authors and Affiliations
Rights and permissions
About this article
Cite this article
Yoon, K.B., Saxena, A. & Mcdowell, D.L. Effect of cyclic overload on the crack growth behavior during hold period at elevated temperature. Int J Fract 59, 199–211 (1993). https://doi.org/10.1007/BF00012361
Received:
Accepted:
Issue Date:
DOI: https://doi.org/10.1007/BF00012361