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Volume 32 (1994)
- Issue 6 Pages 288-
- Issue 5 Pages 240-
- Issue 4 Pages 184-
- Issue 3 Pages 130-
- Issue 2 Pages 66-
- Issue 1 Pages 4-
Predecessor
Volume 32, Issue 6
Displaying 1-5 of 5 articles from this issue
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Toshitaro MIMAKI, Hirotoshi HISHIDA1994 Volume 32 Issue 6 Pages 288-297
Published: November 25, 1994
Released on J-STAGE: August 05, 2010
JOURNAL FREE ACCESSIt can be evaluated deterministically whether brittle fracture of welded steel structures occurs or not by applying fracture mechanics. However, various factors such as fracture toughness, related to the criterion of brittle fracture, are generally thought to be probabilistically distributed. Therefore, reliability analysis is of importance.
For safety assessment based on reliability analysis, it is most important to clarify the probability parameters of the original population distribution. However, it is not easy to accurately estimate the probability parameters from a relatively small size sample data. Based on such finding that fracture toughness can be closely represented by a Weibull distribution, a new parameter estimation method has been developed by making use of the data occurrence characteristics of three-parameter Weibull distribution.
From sensitivity analysis of the average and the variance of fracture toughness by fracture mechanics and Monte Carlo simulation, it is found that the variance of fracture toughness has a significant effect on fracture probability of a spherical tank.
With the estimation method developed, relatively good results can be obtained with 5 to 10 sample size N. At N=5, comparatively good estimates of the average value and the variance are obtained. This sample size is a half of the correlation factor method that has hitherto been appreciated most suitable.View full abstractDownload PDF (942K) -
Hachirou KITAMURA, Naoshige KUBO, Takeyoshi NISHIZAKI1994 Volume 32 Issue 6 Pages 298-308
Published: November 25, 1994
Released on J-STAGE: August 05, 2010
JOURNAL FREE ACCESSThe new LNG storage at Senboku LNG terminal of Osaka Gas Co., Ltd. has employed the prestressed concrete outer tank, which results in higher safety, more economical solution and higher land utilization than existing storage. This containment system, which is the first attempt in Japan, integrates a conventional aboveground LNG storage with double metal walls and a prestressed concrete dike. The above advantages made it possible to store LNG of 140, 000kl, which is one of the largest capacity in the world.
In developing this type of storage system, we have studied the behavior of materials and structures of prestressed concrete under low temperature, the reliability on liquid-tightness of prestressed concrete and so on. We have also investigated the brittle fracture characteristics of heavy thickness 9% nickel steel plates and their welded joints in order to assess its applicability to large scale LNG storage.
This paper describes results of experimental studies to evaluate the safety and efficiency of this new storage system, as well as concept and construction method of the storage.View full abstractDownload PDF (7126K) -
Akira IWATA1994 Volume 32 Issue 6 Pages 309-315
Published: November 25, 1994
Released on J-STAGE: August 05, 2010
JOURNAL FREE ACCESSThe next new century is called “century of light”, so that many new light sources are under development. Free electron laser (FEL) and synchrotron radiation (SR) are expected as suitable light sources in the century. Both light sources are the same kind, because they generate light from free electrons. SR is the first generation and FEL belongs to the second.
SR has been used 30 years ago. As SR can supply 103-105 times brighter X-ray than conventional X-ray generators, SR has gradually improved various uses. For example, semiconductor field, medical field, fundamental science field and so on. At present, 14 facilities are under operation in Japan, and about 40 facilities are in the world, also many are under construction.
On the other hand, FEL is the advanced apparatus for one generation from SR. Therefore, only 4 facilities are under operation in the world, at present. But FEL has both merits of conventional laser and SR, and moreover the additional merit which can not be obtained by conventional lasers. The additional merit is the tunability of laser wave length. From the merit, FEL is called the dream-light source in the next century.
In this paper, the principle and the present status of applications of FEL and SR are shown. The beginning of new relation between the high pressure technology and the new light sources is expected.View full abstractDownload PDF (5077K) -
Introduction of JIS B 8284Shozo YANAGIDA, Akira SUZUKI, Makoto AKATSU1994 Volume 32 Issue 6 Pages 317-322
Published: November 25, 1994
Released on J-STAGE: August 05, 2010
JOURNAL FREE ACCESSPart 3 of this series of articles has been prepared to introduce the strength calculation formulas of an integral type (clamp type with ratches). In this type of closures, the clamp portion that supports a cover plate is situated at the end of a vessel shell as an integral part of a shell itself.
In the case of the integral type (clamp type with ratches), the internal pressure working on a cover plate is supported by plural ratches of a clamp ring via ratches which are formed in the periphery of a cover plate and same in number as those of clamp ring ratches. This type of clamp is similar as the clamp connection type (integral type) introduced in Part 1 and comparatively simple in construction and operation. It should be noted, however, the clamp connection type (integral type) is generally for use of lower pressures (below 10kg/cm2), whereas, the integral type (clamp type with ratches) is serviceable under higher operating pressures.
Strength calculation of the integral type (clamp type with ratches) can be carried out using the calculation formulas given in JIS B 8284 or its Appendix. In addition, this Appendix provides a method for statistically indeterminative stress analysis of discontinuous cross sections with higher accuracy.View full abstractDownload PDF (541K) -
1994 Volume 32 Issue 6 Pages 323-337
Published: November 25, 1994
Released on J-STAGE: August 05, 2010
JOURNAL FREE ACCESSDownload PDF (1882K)
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