10. Fracture Mechanics Approach to Thickness Effects on Brittle Fracture under Large Scale Yielding of Mild Steel
スポンサーリンク
概要
- 論文の詳細を見る
The object of this paper is to evaluate the thickness effect on the brittle fracture toughness of SS41 mild steel accompanied by a large scale plastic deformation ahead of the crack tip. Three points bend specimens and compact tension specimens were used in this test at the temperatures from the room temperature to -150℃. In addition, the authors present the new parameter, β, so called the "constraint coefficient due to the plate thickness", to the evaluation of the thickness effect on the brittle fracture toughness. The relation betweenβ and the plate thickness B is analyzed by using the through-thickness stress distributions, which are estimated by the three dimensional finite element method. Finally, we try to incorporate β into the two dimensional finite clement method and to estimate the critical COD, Φ_<0c>, and J_c for any thickness specimen by using theβ-B relationship. The following conclusions are obtained: 1)Φ_<0c> and J_c at which the brittle fracture occurs are dependent on the plate thickness and little effect of specimen configuration and specimen size. 2) The β-values by this analysis display good agreements with the experimental results. 3) The thickness effects on the deformation of the specimen should be treated as a three dimensional problem, but can be dealt approximately as one of two dimensional problems using the finite element method incorporatingβ.4) It is expected thatΦ_<0c> and J_c for any thickness specimen are able to be calculated by the formulas proposed by authors under the consideration of the thickness effects on the fracture toughness by using a knownΦ_<0c> and J_c for a suitable thickness specimen.
- 社団法人日本船舶海洋工学会の論文
著者
-
Nagai Kin-ichi
University Of Hiroshima
-
Shimizu Shigetoshi
University Of Yamaguchi
-
KAWANO Shun-ichi
University of Yamaguchi