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Volume 46 (2008)
- Issue 6 Pages 344-
- Issue 5 Pages 276-
- Issue 4 Pages 190-
- Issue 3 Pages 116-
- Issue 2 Pages 50-
- Issue 1 Pages 4-
Predecessor
Volume 46, Issue 5
Displaying 1-7 of 7 articles from this issue
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Original Paper
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Haruki NISHI, Minoru YAMADA, Shinsaku ZAMA, Tadashi MIKOSHIBA, Chikahi ...Article type: Original paper
2008 Volume 46 Issue 5 Pages 276-284
Published: September 25, 2008
Released on J-STAGE: January 22, 2009
JOURNAL FREE ACCESSIn the past large earthquakes, such as the 1964 Niigata earthquake, the 1983 Nihonkai-chubu earthquake and the 2003 Tokachi-oki earthquake, large amount of oil overflowed due to liquid sloshing of oil storage tanks excited by long-period strong ground motions. Although such situation has a high potential of fire breakout, we do not know the method to estimate precisely the amount of overflowed oil. Then, we conducted the shaking experiments of the 7. 6m-diameter model tank to find out the possibility of the estimation.
Based on the velocity response spectral method considering non-linearity of liquid sloshing, we obtained the relation between the overflow volume (δV) above the top angle and amount of overflow stream expressed by the liquid height decrement. The relation depends on the liquid surface with or without floating roof and is given by a linear expression of δV, approximately.
Applying the relation to the actual cases in the above-mentioned earthquakes, theestimations gave a good agreement for the case of the 2003 Tokachi-oki earthquake, but underestimated for the case of the 1964 Niigata earthquake and for the case of the Nihonkai-chubu earthquake except for the one case. Thus, it is needed to carry out further research on the estimation of the amount of overflowed oil from an oil storage tank.View full abstractDownload PDF (658K) -
3rd report: Elliptical Deformation of Pontoon Due to Contraction of DeckMasahiko UTSUMI, Kazuo ISHIDAArticle type: Original paper
2008 Volume 46 Issue 5 Pages 285-293
Published: September 25, 2008
Released on J-STAGE: January 22, 2009
JOURNAL FREE ACCESSFor large tanks, the radial second mode of the sloshing is excited by low-frequency components of earthquake motions. In this case, out-of-plane deformation of the deck of single-deck-type floating roof results in radial contraction of the deck in the direction of the excitation, thereby causing elliptical deformation of the pontoon around the deck. The response analysis for this case is presented in this paper. The deformation of the pontoon is analyzed by considering the contraction of the deck as a restricted displacement of the pontoon based on the fact that the contraction versus deformation relationship predicted by the present analysis agrees with that obtained by LS-DYNA. The variation in the strain energy due to the elliptical deformation of the pontoon is transformed into nonlinear functions of the generalized coordinates using the Galerkin method, and is introduced into the system of governing equations for the nonlinear sloshing and the floating roof oscillation. Numerical solution of these equations shows that the elliptical deformation of the pontoon results in large in-plane stress in the circumferential direction.View full abstractDownload PDF (630K) -
Hiroshi KAWATE, Tomoki SAKURAI, Makoto TOYODA, Kazuma KAWANO, Kazuyosh ...Article type: Original paper
2008 Volume 46 Issue 5 Pages 294-303
Published: September 25, 2008
Released on J-STAGE: January 22, 2009
JOURNAL FREE ACCESSThe 2003 Tokachi-Oki earthquake caused severe damage of oil storage tanks due to long-period ground motions. After that, the technical standards of the Fire Service Act regarding the sloshing with floating roof tanks were revised. The influences of non-linearity of fluid behavior and 2nd mode sloshing were taken into consideration using FEA (Finite Element Analysis) code at this time. However, it is not enough that sufficient description about FEA model such as contact definition, time steps, number of element division, hourglass control and seal model. In this paper, the authors present the suitable model of sloshing simulation for floating roof in oil storage tanks using nonlinear FEA code.View full abstractDownload PDF (1393K) -
Macrostructure and temperature distribution near the weld interface in friction welding of cast ironHiizu OCHI, Gosaku KAWAI, Yoshiaki YAMAMOTO, Katsuyoshi MORIKAWA, Yasu ...Article type: Original paper
2008 Volume 46 Issue 5 Pages 304-310
Published: September 25, 2008
Released on J-STAGE: January 22, 2009
JOURNAL FREE ACCESSFriction welding of FC250 common grade cast iron was carried out to examine this weldability and temperature distribution near the weld interface in friction welding. Joint strength was evaluated from tensile strength. A maximum tensile strength in solid joint and pipe joint were 317 MPa (joint efficiency: 79%) and 381 MPa (joint efficiency: 95%) , respectively. In solid joints, a fine-grained structure of FC250 was formed at the weld interface near the axial center and joints fractured along the crack in this layer or along the boundary between this layer and FC250 original material zone. In pipe joints, there was no fine-grained structure. The base metal temperature at the axial center was higher than that at the peripheral part in solid joint. There was a little difference in the temperature distribution between solid joint and pipe joint.View full abstractDownload PDF (1437K) -
Shunji KATAOKA, Takuya SATOArticle type: Original paper
2008 Volume 46 Issue 5 Pages 311-318
Published: September 25, 2008
Released on J-STAGE: January 22, 2009
JOURNAL FREE ACCESSThe inner tube of the double-tube reactors used in some chemical process units must be designed to resist buckling. When the inner tube is operated at a higher temperature and at a lower pressure and outer tube is operated at a lower temperature and at a higher pressure, the inner tube will be subjected to combined thermal loads and external pressure. ASME Code Sec. VIII Div. 1 provides a design procedure for shells, based on a B-chart, to ensure against buckling under external pressure, however, additional consideration should be made where plastic deformation may occur due to very large longitudinal thermal loads.
In this study, nonlinear finite element analyses were performed to investigate the collapse of thick-walled cylindrical shells subjected to combined thermal loads and high external pressures. Two nonlinearities, a material nonlinearity (elastic-plastic behavior) and a geometric nonlinearity (large deformation) , were considered in these analyses. The effects of initial imperfection in the shells (out-of-roundness) as well as of thermal loads were studied. The results showed that the longitudinal thermal loads reduce the plastic collapse load especially when the thermal loads are tensile. It was also shown that the loading sequence has a large effect on the collapse load especially when the thermal stress was larger.View full abstractDownload PDF (775K) -
Koji TAKAHASHI, Kotoji ANDO, Sota WATANABE, Kazuomi KAWATO, Masakazu H ...Article type: Original paper
2008 Volume 46 Issue 5 Pages 319-325
Published: September 25, 2008
Released on J-STAGE: January 22, 2009
JOURNAL FREE ACCESSMonotonic bending tests were conducted using elbow pipe specimens with local wall thinning. The local wall thinning was machined on the inside of pipes in order to simulate erosion⁄corrosion metal loss. Eroded areas were located in three different areas: called extrados, crown and intrados. Effects of the local wall thinning on the failure behaviors of the elbow pipes were evaluated in terms of the plastic collapse moment. The type of failure for all pipes could be classified as ovalization. Crack initiation were not observed.
Three-dimensional elasto-plastic analyses were also carried out using the finite element method, which could accurately simulate failure behaviors.View full abstractDownload PDF (1150K)
Review
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Part4 Nondestructive Examination for Oil Storage Tanks-Evaluation of Corrosion Damage in Bottom Plates of Oil Storage Tanks by Acoustic Emission-Minoru YAMADA, Shigenori YUYAMA, Hiroyuki HAGAArticle type: Review
2008 Volume 46 Issue 5 Pages 326-333
Published: September 25, 2008
Released on J-STAGE: January 22, 2009
JOURNAL FREE ACCESSAcoustic emission testing based on test procedure, database and evaluation criteria has been widely used as a standard method for testing bottom plate conditions in oiI storage tanks. More than 160 tanks have been tested in Japan on the basis of the test procedure since it was introduced to Japanese industry in 1999. After acoustic emission testing, tanks were opened and thickness data were collected. Good correlation has been found between acoustic emission activity and the corrosion risk parameter (ccrresponding corrosion rate) resulting from a statistical ana1ysis of the thickness data from discrete point thickness measurement. Ultrasonic bottom p1ate scan testing has been conducted to verify the reliability of the correlation. This paper presents some case studies, comparing the acoustic emission data with bottom plate scan testing resu1ts. The reliability of acoustic emission testing in terms of source location and thickness mapping is discussed with the aid of location figures. The case studies have been made partly as the research project of the High Pressure lnstitute of Japan, sponsored by the Japan Oil, Gas and Metal National Corporation.View full abstractDownload PDF (619K)
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