巻号一覧
35 巻 (1997)
- 6 号 p. 300-
- 5 号 p. 236-
- 4 号 p. 174-
- 3 号 p. 116-
- 2 号 p. 42-
- 1 号 p. 2-
前身誌
35 巻, 6 号
選択された号の論文の9件中1～9を表示しています
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関根 和喜, 日向 直之1997 年 35 巻 6 号 p. 300-307
発行日: 1997/11/25
公開日: 2010/08/05
ジャーナル フリーIn recent years, the demand for the reliable and economically justifiable assessment techniques for integrity of large scale above-ground oil storage thanks, as ones of the aging infrastructures, is increasing.
Under this situation of Japan, the HPI (the High Pressure Institute of Japan) made the adhoc committees, which have been sponsored by the Japan National Oil Corporation (石油公団), working on the necessary technologies to assess the integrity and to provide the rational maintenance for the national crude oil storage tanks exceeding a capacity of 100,000kl. The committees addressed mainly on the problems of underside corrosion of the bottom floors, on the durability evaluation technique of internal protective-coating systems, and also on fracture mechanical assessment method for crack growth behavior at the toe of shell-annular fillet welds when, especially, the tank undergoes a strong earthquake, with along reliable through-coating NDT techniques for cracks in the welds. Some of the results in the committee works for six years since 1991 are presented in this issue.
This article surveys the present situation of above-ground tank management and integrity evaluation technologies in Japan. It also focuses on some problems posed and identified from the adhoc committee works, which are on the underside corrosion of tank floors, on the internal coating and linings used as the corrosion protection and on the defect assessment method for cracks in fillet welds, including the through-coating NDT techniques for harmaful cracks to stuctural soundness in above-ground oil tanks.抄録全体を表示PDF形式でダウンロード (1102K) -
石田 和雄, 茨田 高志, 河野 和間, 関根 和喜, 日向 直之1997 年 35 巻 6 号 p. 308-316
発行日: 1997/11/25
公開日: 2010/08/05
ジャーナル フリーIt is very important in safety design of oil storage tanks to prevent their bottom plates from corrosion and to ensure them against earthquake damage. When a violent earthquake occurs, a part of the shell plate of unanchored cylindrical oil storage tanks will be lifted from their foundations due to overturning moment, and local strain of annular bottom plate near the shell to annular joint will increase. As the result, damage such as cracks of coating material on annular plate may be caused. This paper deals the uplift behavior of tanks due to earthquake.
In order to evaluate quantitatively the uplift displacement of shell lower edge of 110000m3 oil storage tanks by earthquakes, nonlinear time history analyses were carried out by using mechanical model of mass-spring system, where non-linearity associated with the partial uplift of shell plate is considered as rotational spring of a bilinear type. The analytical results show that EW direction wave of “Far off Sanriku earthquake (1994)” (with maximum acceleration 293gal) causes the maximum uplift about 5cm at shell lower edge. The critical value of shell uplift prescribed in evaluation of “existing horizontal load bearing capacity” of tanks by current Fire Service Law is regarded as about 21cm. Therefore the calculated uplift value of 5cm is lower than the critical value.抄録全体を表示PDF形式でダウンロード (851K) -
河野 和間, 山田 實, 石田 和雄, 久保山 孝治, 吉田 聖一, 関根 和喜, 日向 直之1997 年 35 巻 6 号 p. 317-328
発行日: 1997/11/25
公開日: 2010/08/05
ジャーナル フリーThe shell-to-bottom joint of unanchored oil storage tank will uplift due to overturning moment applied to the tank against strong horizontal seismic excitation, and excessive plastic strain cyclically occurs in this joint. Three large tanks spilled their contents over the port due to the failure caused by uplifting force applied to the tank shell in the 1978 Miyagiken-oki earthquake. This paper presents the systematic evaluation for structural integrity of a large-sized oil storage tank against strong earthquake. In the first method of this study, the nonlinear seismic response analysis taking the uplifting force applied to the tank shell into consideration is carried out, and useful information on the relation between the seismic character and the uplift displacement is derived. The second method is the elastic-plastic, large displcement finite element stress analysis of the shell-to-bottom joint under uplifting load. The relation between the peak strain at the toe of fillet weld of this joint and the seismic character is obtained from the 1st and 2nd method. Crack initiation and crack propagation behavior under cyclic bending load is investigated on the speciments with fillet weld joint by the experimental test for low cycle fatigue. The relation between the peak strain and the fatigue life at the toe of fillet weld of this joint is finally obtained. Consequently, the tank's integrity can be evaluated on the viewpoint of the seismic character, the uplift displacement of the shell-to-bottom joint, the peak strain and the fatigue life at the toe of weld of this joint.抄録全体を表示PDF形式でダウンロード (1197K) -
引張圧縮試験におけるき裂進展伊木 聡, 井上 純一郎, 川原 正言, 河野 武亮, 関根 和喜, 日向 直之1997 年 35 巻 6 号 p. 329-336
発行日: 1997/11/25
公開日: 2010/08/05
ジャーナル フリーMany countries have suffered from large earthquakes in the past few decades. Especially in Petroleum Storage Tank, extensive efforts are required to estimate the fracture behavior under cyclic plastic strains so as to prevent or minimize fatal accidents. Crack growth rates under cyclic loads have been generally analyzed by Paris'law by using a linear elastic fracture mechanics concept, “ΔK”, stress intensity factor range. But, this approach cannot be valid in the repeated large plastic deformations.
This paper proposes an approximate method to evaluate crack growth rates under repeated large plastic deformation by using an easier formulation based on an approximate analysis of pseudo J parameter. Crack growth experiments have been conducted under cyclic axial plastic loadings in order to verify the validity of the proposed formula.抄録全体を表示PDF形式でダウンロード (4052K) -
西村 一実, 新頭 英俊, 石本 裕保, 屋敷 孝志1997 年 35 巻 6 号 p. 337-345
発行日: 1997/11/25
公開日: 2010/08/05
ジャーナル フリーCorrosion performance of hot-dip galvanizing steel sheet applied on the oil tank roof was investigated by the laboratorical corrosion simulation test and the exposure test. The corrosion environment of inner side of oil roof was assumed to be dry and wet condition which pH indicate about 5 containing sulfuric acid by examination of corrosion products. Galvanizing steel sheet showed excellent corrosion resistance in the accelated test-water spray test containing sulfuric acid and the exposure test in the real oil roof. Welding condition of these galvanizing steel sheet was also important factor in the corrosion resistanse. Galvanic protection action of Zn was also effective in the heat affecting zone by welding.
From these results, the life cycle of oil tank will be prolonged by application of Galvanizing steel sheet.抄録全体を表示PDF形式でダウンロード (11845K) -
山田 實, 関根 和喜, 日向 直之, 河野 和間, 中田 勝康1997 年 35 巻 6 号 p. 346-350
発行日: 1997/11/25
公開日: 2010/08/05
ジャーナル フリーIn order to examine the surface strain at crack initiation of coating material on annular plates of oil storage tank, the authers experimented with model specimens of coated steel plate. Five kinds of vinyl-ester resion system (C1 to C5) including glass flakes were tested as coating materials. The strain on steel plate surface corresponding to coating crack initiation strain of specimen C3 was about 0.54%, and those of other specimens were more than 0.7%. Maximum peak strain on inner surface of annular plate calculated from the non-linear time history analysis results against the seismic wave of “Sanriku far offshore earthquake (1994)” was about 0.69%. These results show that cracks of coating material on annular plates may occur in case of C3 by this level earthquake.抄録全体を表示PDF形式でダウンロード (5781K) -
中田 勝康, 石井 正義, 関根 和喜, 日向 直之1997 年 35 巻 6 号 p. 351-357
発行日: 1997/11/25
公開日: 2010/08/05
ジャーナル フリーGlass-flake coating applied on the inside of crude oil storage tank bottoms has realized good corrosion protection. However, as some kinds of damage in aged coating films, blistering or delamination of coating were observed incidentally, it is very important to prevent from them for long time serviced tanks.
The research work by the adhoc committee, which has been organized by the HPI, has been performed on cause and prevention of blistering and durability evaluation of glass-flake coating since 1991.
By means of examination of many blisters of coating on tank bottoms and accelerating test of blistering in laboratory, it becomes clear for glass-flake coating as follows:
(1) The cause of blistering and their effects on durability of coatings were specified and the preventive techniques for blistering has been proposed.
(2) A durability limit estimation of aged coating film was succesful by measuring of the change in electric properties.
(3) The accelerating test method (the HPI-TD method) for blistering of coating was proposed.
(4) The availability of refresh coating for extension of durability limit for used coating was proved by the field examinations for real tanks.抄録全体を表示PDF形式でダウンロード (722K) -
小林 豊治1997 年 35 巻 6 号 p. 358-362
発行日: 1997/11/25
公開日: 2010/08/05
ジャーナル フリーCauses and mechanisms of external and internal corrosion of tank bottoms are discussed. Some recent methods for monitoring and control of corrosion are described.抄録全体を表示PDF形式でダウンロード (569K) -
(社) 日本高圧力技術協会1997 年 35 巻 6 号 p. 363-379
発行日: 1997/11/25
公開日: 2010/08/05
ジャーナル フリーPDF形式でダウンロード (2252K)
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