Many experimental investigations have previously been performed and recentlydone on different shipbuilding structural steels where the specimens size and crack depth/specimenwidth (a/W) were varied. A series of intere...Many experimental investigations have previously been performed and recentlydone on different shipbuilding structural steels where the specimens size and crack depth/specimenwidth (a/W) were varied. A series of interesting results have been gained. It is worthwhile to havea review on the effect of a/W ratio on fracture toughness, and further theoretical analysis isnecessary. In this paper, experimental work in elastic-plastic fracture mechanics (EPFM) wasdiscussed. Tests had been carried out on 10 kinds of strength steels. Results showed that J_i andδ_i. values increased with decreasing a/W when a/W【0.3 for three-point bend specimens and thatshallow crack specimens which have less constrained flow field give markedly higher values oftoughness than deeply notched specimens. However, for a/W】0.3, the toughness was found to beindependent of a/W. Slip line field analysis shows that for shallow cracks, the hydrostatic stressis lower than that from standard deeply cracked bend specimen which develops a high level of cracktip constraint, provides a lower bound estimate of toughness, and will ensure an unduly conservativeapproach when applied to structure defects especially if initiation values of COD / J-integral areused.展开更多
Background People put more and more emphasis on protection of living environment there are unprecedented focuses on ecological environment and sustainable development. As the
March is a right party time for friends to get together to enjoy the smell of early spring. Moreover, people would like to take off the thick winter coat to showcase their colorful attitude towards the warm spring sun...March is a right party time for friends to get together to enjoy the smell of early spring. Moreover, people would like to take off the thick winter coat to showcase their colorful attitude towards the warm spring sunshine. Here, an annual fashion feast in Beijing not only could provide you a visual inspiration of trend, but also would tell you what’s the most "in" factors in the coming season.展开更多
Color trend insights extremely benefit textile and fashion industries What is the next big Trend? This is not just the question to get dressed in trend. But trends information is highly essential for designers
On July 9th,Heng Yuan Xiang Corporation released its 10/11 A/W Cashmere Collections for Women’s Wear in Beijing.Nearly 200 brand sagents and franchisers from 16 provinces took part in the press conference,looking for...On July 9th,Heng Yuan Xiang Corporation released its 10/11 A/W Cashmere Collections for Women’s Wear in Beijing.Nearly 200 brand sagents and franchisers from 16 provinces took part in the press conference,looking for their target series for the coming season.展开更多
In part I and II of this series, experimental investigation in both EPFM and LEFM had been discussed. In this part, further theoretical analysis is given. The theoretical development of Two Parameter Fracture Mechanic...In part I and II of this series, experimental investigation in both EPFM and LEFM had been discussed. In this part, further theoretical analysis is given. The theoretical development of Two Parameter Fracture Mechanics by Hancock etc, has rationalized our experimental results. This method can be applied to engineering practice, and will allow the advantage of enhanced toughness for specimens with low levels of constraint to be taken into account for defect assessment.展开更多
文摘Many experimental investigations have previously been performed and recentlydone on different shipbuilding structural steels where the specimens size and crack depth/specimenwidth (a/W) were varied. A series of interesting results have been gained. It is worthwhile to havea review on the effect of a/W ratio on fracture toughness, and further theoretical analysis isnecessary. In this paper, experimental work in elastic-plastic fracture mechanics (EPFM) wasdiscussed. Tests had been carried out on 10 kinds of strength steels. Results showed that J_i andδ_i. values increased with decreasing a/W when a/W【0.3 for three-point bend specimens and thatshallow crack specimens which have less constrained flow field give markedly higher values oftoughness than deeply notched specimens. However, for a/W】0.3, the toughness was found to beindependent of a/W. Slip line field analysis shows that for shallow cracks, the hydrostatic stressis lower than that from standard deeply cracked bend specimen which develops a high level of cracktip constraint, provides a lower bound estimate of toughness, and will ensure an unduly conservativeapproach when applied to structure defects especially if initiation values of COD / J-integral areused.
文摘Background People put more and more emphasis on protection of living environment there are unprecedented focuses on ecological environment and sustainable development. As the
文摘March is a right party time for friends to get together to enjoy the smell of early spring. Moreover, people would like to take off the thick winter coat to showcase their colorful attitude towards the warm spring sunshine. Here, an annual fashion feast in Beijing not only could provide you a visual inspiration of trend, but also would tell you what’s the most "in" factors in the coming season.
文摘Color trend insights extremely benefit textile and fashion industries What is the next big Trend? This is not just the question to get dressed in trend. But trends information is highly essential for designers
文摘On July 9th,Heng Yuan Xiang Corporation released its 10/11 A/W Cashmere Collections for Women’s Wear in Beijing.Nearly 200 brand sagents and franchisers from 16 provinces took part in the press conference,looking for their target series for the coming season.
文摘In part I and II of this series, experimental investigation in both EPFM and LEFM had been discussed. In this part, further theoretical analysis is given. The theoretical development of Two Parameter Fracture Mechanics by Hancock etc, has rationalized our experimental results. This method can be applied to engineering practice, and will allow the advantage of enhanced toughness for specimens with low levels of constraint to be taken into account for defect assessment.
