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Volume 31 (1993)
- Issue 6 Pages 324-
- Issue 5 Pages 264-
- Issue 4 Pages 192-
- Issue 3 Pages 114-
- Issue 2 Pages 58-
- Issue 1 Pages 3-
Predecessor
Volume 31, Issue 2
Displaying 1-5 of 5 articles from this issue
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Hiroshi MIMURA1993 Volume 31 Issue 2 Pages 58-64
Published: March 25, 1993
Released on J-STAGE: August 05, 2010
JOURNAL FREE ACCESSBy using a simple model, a method was proposed to calculate size of crack side ligaments formed during brittle crack propagation. The crack side ligaments cause difference between K1a and Kca.
The present method can explain the following items which are well known empirically.
(1) Kca can be said to be a material constant when measured by means of the standard ESSO test.
(2) Kca can not be a material constant when measured by means of the ultra wide plate ESSO test.
It was concluded that the current fracture control method based on Kca of the standard ESSO test is always on conservative side.View full abstractDownload PDF (707K) -
Noriyuki MIYAZAKI, Seiya HAGIHARA, Tsuyoshi MUNAKATA1993 Volume 31 Issue 2 Pages 65-73
Published: March 25, 1993
Released on J-STAGE: August 05, 2010
JOURNAL FREE ACCESSIn the present study, theoretical and experimental investigation were performed on the creep buckling. Special attention was focussed on the bifurcation behavior during creep deformation.
The finite element method was used to analyze the creep buckling of a perfect circular cylindrical shell without initial imperfection. The number of circumferential waves obtained from this analysis agrees well with that of the experiment. The present experimental investigation shows that the circumferential waves suddenly appear near a bulge. It is also found that there is no correlation between the wave length of the circumferential waves observed at the creep buckling and that of circumferential initial imperfection. The deformation pattern at the bifurcation creep buckling obtained from the analysis resembles that of the experiment. It is concluded from the analysis and the experiment that the circumferential waves observed in the creep buckling experiment are due to bifurcation during creep deformation.View full abstractDownload PDF (3737K) -
Satoshi YAMAMOTO, Masahiro TAKANASHI, Kunihiro IIDA1993 Volume 31 Issue 2 Pages 74-81
Published: March 25, 1993
Released on J-STAGE: August 05, 2010
JOURNAL FREE ACCESSAn experimental confirmation of the relaxation behaviour of welding residual stresses under fatigue loading was made using more than 30 plate specimens. Type 316 stainless steel plates in 4mm thickness (0.2% proof stress=255MPa, UTS=568MPa) were butt welded by electron beam welding. The longitudinal welded joint specimens were machined out, and a center hole of 8mm diameter was drilled at the center of the specimen in order to localize the fatigue crack initiation point. The specimen was subjected to one cycle static loading or to fatigue cycling with reversed axial loading in the crack initiation life range between 104 and 107 cycles. A specimen was removed from the testing machine after the repetition of load cycling of a given number in order to measure the change of residual stress distribution. In addition comparative fatigue tests of both base plates specimens and longitudinal butt welded joint specimens were conducted using specimens with a center hole.
The peak value of longitudinal welding residual stress decreases remarkably by the first cycle of fatigue loading, showing 48% reduction by 200MPa maximum load and 23% reduction by 130MPa loading. The welding residual stress then decreases gradually with the followed repetition of fatigue loading. The fatigue strength of longitudinal welded joint specimen is considerably lower than that of base plate specimen especially in higher cycle regime.View full abstractDownload PDF (1893K) -
A Two Criteria ApproachHitoshi YOSHINARI1993 Volume 31 Issue 2 Pages 83-98
Published: March 25, 1993
Released on J-STAGE: August 05, 2010
JOURNAL FREE ACCESSIn order to evaluate safety of the structures, establishment of the method of fracture strength assessment with high accuracy is needed. In England, two widely applied methods for fracture assessment have been developed, namely, BSI PD6493 and CEGB R6 approach. The BSI procedure is now under revision, so that it can take into account the benefit of CEGB R6 approach and the recent advancement of fracture mechanics. The CEGB R6 approach has lately attracted considerable attention. The notable feature of it is that the approach interpolates between two criteria, that is, LEFM failure and plastic collapse.
On the other hand, the fracture assessment method based on the CTOD design curve approach has been developed in Japan, that is, WES standard 2805. This standard adopted an elastic-plastic fracture parameter CTOD as a judgement criterion, because brittle fracture may occur from defects at structural stress concentration where plastic size generally seems to be greater than defect size.
This paper describes the main points of the above three fracture assessment methods. Although these three methods alike are based on the elastic-plastic fracture mechanics, it seems that the methods of BSI and R6 are quite different from WES approach in appearance. The purpose of this paper, therefore, is to clarify the relation of these methods. Recent numerical and experimental studies on fracture strength assessment are also presented.View full abstractDownload PDF (1561K) -
Shoichi YOSHIDA, Toshiro MIYOSHI1993 Volume 31 Issue 2 Pages 99-103
Published: March 25, 1993
Released on J-STAGE: August 05, 2010
JOURNAL FREE ACCESSOn January 2, 1988, the oil storage tank at the Ashland Petroleum Company Floreffe terminal, Pennsylvania, U. S. A. collapsed as it was being filled. As a result of the failure approximately 14600kl of diesel fuel was released. This paper describes the failure from the viewpoint of linear fracture mechanicsView full abstractDownload PDF (499K)
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