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Volume 35 (1997)
- Issue 6 Pages 300-
- Issue 5 Pages 236-
- Issue 4 Pages 174-
- Issue 3 Pages 116-
- Issue 2 Pages 42-
- Issue 1 Pages 2-
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Volume 35, Issue 2
Displaying 1-7 of 7 articles from this issue
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Goichi BEN, Akira MOROI, Hirosh OOTA1997 Volume 35 Issue 2 Pages 42-50
Published: March 25, 1997
Released on J-STAGE: August 05, 2010
JOURNAL FREE ACCESSNatural gas vehicles are now attracted extensive public attention for the reason of reducing atomospheric pollusion and they are considered as one of the most reliable and promising alternative fuel vehicles. In order to realize these vehicles, light pressure vessels, containing highly compressed gas should be developped. Before discussing the pressure vessel having domes and for deeply understanding it, the present paper first discusses the mechanical behaviors and structural optimum design of cylindrical pressure vessels from the two viewpoints of initial failure and ultimate fracture. Next, this papar discribes the structural analyses of all composite vessels in which thermoplastic polymer is used as a liner and it is wound circumferentially and helically with CFRP. Furthermore, this paper shows the effects of using hybrid FRP as the winding material on the maximum values of stresses and compares the results of the thermoplastic liner with ones of aluminum alloy.View full abstractDownload PDF (899K) -
Influence of hoop winding end position upon burst pressureTatsumi TAKEHANA1997 Volume 35 Issue 2 Pages 51-57
Published: March 25, 1997
Released on J-STAGE: August 05, 2010
JOURNAL FREE ACCESSThis paper discusses on the stress distribution control in FRP composite cylinders in relation with the weight-saving and quality improvement of cylinders. A series of experiments were conducted to study the influence of hoop winding end positoin upon the burst pressure of gas cylinders. Stress distributions were examined both by FEM analysis and experiments. The results showed the importance of the control of hoop winding end position to improve the performance and the security of cylinders.View full abstractDownload PDF (2392K) -
Taiji MAEDA, Hisao MATSUSHITA, Shinji KONOSU1997 Volume 35 Issue 2 Pages 58-64
Published: March 25, 1997
Released on J-STAGE: August 05, 2010
JOURNAL FREE ACCESSIn order to clarify the fatigue behavior of welded joints connecting an outer plate to the keel of a ship made of JIS A 5083 alloy, constant displacement amplitude fatigue tests of the welded joints (four types) were conducted. Additionally, a finite element method (FEM) analysis and residual stress measurements were carried out. The FEM analysis gave a fairly good estimation of the elastic strain distribution near the toe of the weld. The life evaluation procedure was proposed based on Dowing's stress based approach.
By analysis incorporating quantitatively the effects of stress concentration, welding residual stress and mean stress on the fatigue life of the welded joints, the relationship giving the 95% confidence limits between the equivalent completely reversed stress amplituede σar and cycles to failure Nf was given by the following formula.
σar(MPa)=A⋅NfB: A=702-453, B=-0.17.
This empirical relation appears very useful for designing favorable welded joints for shipbuilding purposes.View full abstractDownload PDF (2193K) -
Toshitaro MIMAKI, Masao OGASAWARA, Yoichi YAZAKI1997 Volume 35 Issue 2 Pages 65-78
Published: March 25, 1997
Released on J-STAGE: August 05, 2010
JOURNAL FREE ACCESSThe application of casing in a high pressure well increasingly exposes various problems in the performance of casings. One of the biggest concerns is seal tightness of connection, since an available criterion for seal tightness is not fully determined. In general, not only premium connection (PJ) but also API connection have a high seal tightness and there are few troubles of leakage. A tentative criterion for seal tightness of the radial seal surface of PJ has been proposed. The criterion is derived from experimental leak test results and Finite Element Analysis. It is also composed of sealing contact pressure and contacting width on the radial seal surface. However, the criterion is not yet formulated.
In this paper, the criterion is evaluated by approximate application of the thin cylindrical shell theory and is formulated. The results are summarized as follows:
1) A criterion for seal tightness of the radial seal surface is formulated by two factors, i. e., sealing contact pressure and contacting width.
2) The criterion is formulated using the function type. derived from the thin cylindrical shell theory, i. e., it is represented by a multiplier of sealing pressure and 2-order polynomial of contacting width.View full abstractDownload PDF (3127K) -
Toshiyuki MIYAKE, Shigeru OHKITA1997 Volume 35 Issue 2 Pages 79-89
Published: March 25, 1997
Released on J-STAGE: August 05, 2010
JOURNAL FREE ACCESSThe applicability of increased arc energy TIG process was tested to 9% nickel steel.
The results are summarized as follows.
(1) The increased arc energy TIG process shows better penetration characteristics as compared with conventional TIG process at same welding current, arc voltage and wire feeding speed.
(2) This TIG process has been succesefully applied to 9% nickel steel with high efficiency and high quality.
(3) The welded joints made with this TIG process showed good CTOD characteristics.View full abstractDownload PDF (2354K) -
Norihiko KATAYAMA, Akio TEJIMA, Shinya WATANABE, Sakae TOMIDOKORO, Kaz ...1997 Volume 35 Issue 2 Pages 90-97
Published: March 25, 1997
Released on J-STAGE: August 05, 2010
JOURNAL FREE ACCESSRemote control TIG welding system for large 9% Ni-steel LNG storage tanks has been developed. The system incorporates laser seam tracking by digital image processing, an arc monitor TV system, programming control of welding conditions, self diagnosis system for the equipment working status, and graphical interface using a color display. The operator may safely and easily operate the multiple equipments, even if the distance between the welding head and controler is 115m.
Twin-Pulse TIG welding method applied successfully to keep stable fine penetration especially for inner layers of narrow groove, and to improve the deposition rate up to 20%, compared with that of conventional hot wire TIG welding method. It was also confirmed that the narrow groove welded joint of 50mm thickness has sufficient strength and fracture toughness at LNG temperature.View full abstractDownload PDF (5424K) -
Yoshiyasu ITOH, Masahiro SAITOH, Masashi TAKAHASI, Hideo KASHIWAYA1997 Volume 35 Issue 2 Pages 98-106
Published: March 25, 1997
Released on J-STAGE: August 05, 2010
JOURNAL FREE ACCESSThermal barrier coatings (TBCs) had been already applied to hot section parts of gas turbines, such as a bucket and a combustor. It is thought that the TBCs are indispensable for the gas turbines in company with a cooling technology. Nowadays, it is desired the higher durability to TBCs with increasing the combustion temperature. For the sake of this situation, it is necessary to introduce a design concept into the coating technology.
In this paper, the coating design concept makes clear for gas turbines. And, the coating design system, that consists of a thermal stress analysis and a reaction diffusion analysis, and its application is showed. For developing the high-durable TBCs, the coating design was conducted for a gas turbine nozzle. This study led to the conclusion that the improved TBCs could be obtained by introducing the oxidation resistant layer by aluminizing. The developed TBC system was applied to the gas turbine nozzle.View full abstractDownload PDF (6384K)
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