Elastic-plastic behaviours of pressurised pipes under cyclic thermal stresses with temperature gradients
Elastic-plastic behaviours of pressurised pipes under cyclic thermal stresses are investigated in this paper, incorporating temperature (and resulting the yield strength) gradient across the pipe thickness. Based on analytical investigations, explicit equations for various stress regimes representing elastic-plastic behaviours are obtained. In the limiting case of no temperature (yield strength) gradient across the thickness, proposed equations recover those for the Bree diagram. For the case when temperature (yield strength) gradient exists across the thickness, overall shapes of stress regimes are slightly different from those in the Bree diagram. The main difference is the shakedown and elastic regimes. Due to the yield strength variation across the thickness, shakedown should be checked at the inner wall, at the outer wall, and at both walls. Accordingly elastic limit should be checked at the inner and at the outer walls. As results, boundaries between elastic and shakedown regimes in the proposed diagram are different from those in the Bree diagram. Another difference is the plastic collapse regime which is not present in the Bree diagram. Boundaries between shakedown and ratchetting or reverse plastic in the proposed diagram are quite similar to those in the Bree diagram.
Cyclic thermal stresses Elastic-plastic behaviours Pressurised pipes Temperature and strength gradient
Chang-Sik Oh Yun-Jae Kim
Department of Mechanical Engineering, Korea University, 5 Ka, Anam-dong, Sungbuk-Ku, Seoul 136-701, Korea
国际会议
国际断裂力学2007年会(Fracture Mechanics and Applications 2007)
长沙
英文
47-56
2007-11-01（万方平台首次上网日期，不代表论文的发表时间）