PSI - Issue 2_B

Shimada Y. et al. / Procedia Structural Integrity 2 (2016) 1593–1600

1600

Yusuke Shimada / Structural Integrity Procedia 00 (2016) 000–000

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6. Conclusion

Strength variation due to pre-straining, dynamic loading and temperature was investigated for 400 -780 MPa class steel plate and 400 - 490 MPa class H-section steel. As a result, the following conclusions can be made. • A method for estimating the yield strength and tensile strength of pre-strained steel from the true stress - true strain curve of virgin steel is proposed. In addition, changes in the yield strength and tensile strength of pre strained steel can be predicted by the new equations based on experimental results. • The variations in both yield strength and tensile strength due to dynamic loading and temperature could be estimated by the proposed equations, which use the R parameter. These equations are based on old equations of WES 2808:2003 • Methods of predicting strength variation due to pre-strain, dynamic loading and temperature were proposed. The change in the strength of steel when both pre-straining and dynamic loading were applied can be estimated as the sum of amount of strength variation due to pre-straining and the amount of strength variation due to dynamic loading of the pre-strained steel. References Bennett P.E., Sinclair G.M., 1961. Trans. of ASME. Journal of Basic Engineering 33, pp. 557. Bennett P.E., Sinclair G.M., 1966. Parameter representation of low-temperature yield behavior of body-centered cubic transition metals. Trans. of ASME. pp. 518. Igi, S., Shimada, Y., Kinefuchi, M., Minami, F., 2016. WES 2808 for brittle fracture assessment of steel components under seismic conditions -Part III: Change in CTOD fracture toughness of structural steels by pre-strain and dynamic loading. Structural Integrity Procedia, to be published. Inoue T., Hagihara Y., and Tanaka K., 1987. Prep. Nat. Meet. JWS, No. 41 380 (in Japanese) Kubo T., Igi S., Handa T., Suzuki N., Toyoda M., Ohata M., Minami F., 2007. Application of WES2808 to Brittle Fracture Assessment for High Strength Gas Pipelines. Proceeding of the 26th International Conference on Offshore Mechanics and Arctic Engineering. OMAE2007-29246 Minami. F., Arimochi, K., 2001. Evaluation of Pre-Straining and Dynamic Loading Effects on the Fracture Toughness of Structural Steels by the Local Approach. Journal of Pressure Vessel Technology 123, 362-372.