巻号一覧
前身誌
54 巻, 1 号
選択された号の論文の3件中1～3を表示しています
- |<
- <
- 1
- >
- >|
論文
-
吉田 聖一原稿種別: 論文
2016 年 54 巻 1 号 p. 4-15
発行日: 2016/01/25
公開日: 2016/02/17
ジャーナル フリーLarge aboveground oil storage tanks are unanchored and rest freely on flexible foundation. The shell-to-annular joint of unanchored oil storage tanks will uplift due to strong seismic excitation, and a large plastic strain occurs in this joint. This paper presents the elastic-plastic, large deformation behavior of the uplifted shell-to-annular joint using axisymmetric finite element analysis. In the analysis, the uplift behavior is assumed to be axisymmetric. The constitutive equation is based on the J2 flow theory with the kinematic hardening rule. The ductile fracture strength characteristics of uplifted shell-to-annular joint in a large tank with capacity 90, 000m3 were reported. The following conclusions were obtained. Even if the fillet weld surface in the shell-to-annular joint becomes smooth, the stress and strain does not change except for the toe. The yield stress of a welded metal at the joint does not influence the strength of annular plate. The strength at the joint becomes high when liquid density is high.抄録全体を表示PDF形式でダウンロード (1630K) -
中島 康毅, 齋藤 裕樹, 蓮沼 将太, 小川 武史原稿種別: 論文
2016 年 54 巻 1 号 p. 16-24
発行日: 2016/01/25
公開日: 2016/02/17
ジャーナル フリーRecent surge for seismic resistance requires an evaluation for welded pipes under mechanical conditions including plastic deformation. Although the welded metal and the heat affected zone have different mechanical properties compared with those of the base material, these local characteristics are difficult to measure. Indentation test is one of the possible solutions for evaluating local mechanical properties including plastic stress-strain response, however, there are many experimental difficulties for the measurement. The present study aims to modify the method simple and convenient using an observation of dents similar to the conventional hardness testing. The modified method was applied to weld joints of piping steels and utilized to investigate the influence of local mechanical properties of the weld metal on the surrounding stress distribution. The piping steels exhibit remarkable yield elongation under the lower yield point, which is not taken into account in the indentation tests measuring the local mechanical properties. Stress-strain response was evaluated under the tensile test using a digital image correlation technique, by which local and bulk strains could be obtained simultaneously. Based on the result, limitations of the indentation method were discussed.抄録全体を表示PDF形式でダウンロード (2011K) -
-温度勾配下におけるふくれ成長の定量的評価-伊藤 大輔, 徳武 皓也, 岡崎 慎司原稿種別: 論文
2016 年 54 巻 1 号 p. 25-34
発行日: 2016/01/25
公開日: 2016/02/17
ジャーナル フリーThe degradation process of a heavy-duty coating with blisters formed by a temperature difference across the resin was investigated by electrical impedance measurements and visual observations. The two effects of the coating thickness and the addition of the glass flakes were evaluated. From the coating impedance monitoring results for 105 days, it was demonstrated that the decrease of barrier property of the coating is inhibited by the addition of glass flakes. By visual observations, it was shown that the area of blisters and the black rust at the coating⁄steel substrate beneath blisters in thick coatings are larger than that in the thin coatings. On the other hand, the prolongation of the time for blistering of the coating could be achieved by the increase of the coating thickness. Finally, the electrical equivalent circuit (EEC) model was proposed for the residual lifetime evaluation of the coating. This model includes the constant phase element (CPE) , one of the circuit elements that can express coating impedance accurately. It was elucidated that the coating impedance can be well-described by the EEC model of the parallel combination of two CPEs.抄録全体を表示PDF形式でダウンロード (1200K)
- |<
- <
- 1
- >
- >|