The formation strength plateau of ceramics is addressed. A set of of 99A1203 are conducted, mechanism of the residual subjected to thermal shock thermal shock experiments where the thin specimens of 1 mm× 10 mm&...The formation strength plateau of ceramics is addressed. A set of of 99A1203 are conducted, mechanism of the residual subjected to thermal shock thermal shock experiments where the thin specimens of 1 mm× 10 mm×50 mm exhibit parallel through edge cracks, and thus permit quantitative measurements of the crack patterns. The cracks evolve with the severity of ther- mal shock. It is found that there is a correlation between the length and density of the thermal shock cracks. The increase of crack length weakens the residual strength, whereas the increase of crack density improves it. In a considerably wide temperature range, the two contrary effects just counteract each other; consequently a plateau appears in the variation curve of the residual strength. A comparison between the numerical and experimental results of the residual strength is made, and they are found in good agreement. This work is helpful to a deep understanding of the thermal shock failure of ceramics.展开更多
Inl this investigation the different tests were carried out on the butt joints of several kinds of steels to study the effects of weldmatching on the fracture initiation under statie and dynamic loading, on the fractu...Inl this investigation the different tests were carried out on the butt joints of several kinds of steels to study the effects of weldmatching on the fracture initiation under statie and dynamic loading, on the fracture propagating arresting properties, on the fatigue behavior and finally on the residual stress distribution, The testing results show that overmatching of metal increases the possibility of having a general yieleding and may help to enlarge the tolerate of weld defects for crack initiation under dynamic or static loading. In the propagating and arresting cases the beneficial effct of overmatching of weld metal was found .However non significant effect of the weldmatch mg on the propagation thresholds △Kth and da'dN was found.展开更多
基金supported by the National Natural Science Foundations of China (10972020,11061130550)Fundamental Research Funds for the Central UniversitiesNational Agency for Research of France (International project T-shock)
文摘The formation strength plateau of ceramics is addressed. A set of of 99A1203 are conducted, mechanism of the residual subjected to thermal shock thermal shock experiments where the thin specimens of 1 mm× 10 mm×50 mm exhibit parallel through edge cracks, and thus permit quantitative measurements of the crack patterns. The cracks evolve with the severity of ther- mal shock. It is found that there is a correlation between the length and density of the thermal shock cracks. The increase of crack length weakens the residual strength, whereas the increase of crack density improves it. In a considerably wide temperature range, the two contrary effects just counteract each other; consequently a plateau appears in the variation curve of the residual strength. A comparison between the numerical and experimental results of the residual strength is made, and they are found in good agreement. This work is helpful to a deep understanding of the thermal shock failure of ceramics.
文摘Inl this investigation the different tests were carried out on the butt joints of several kinds of steels to study the effects of weldmatching on the fracture initiation under statie and dynamic loading, on the fracture propagating arresting properties, on the fatigue behavior and finally on the residual stress distribution, The testing results show that overmatching of metal increases the possibility of having a general yieleding and may help to enlarge the tolerate of weld defects for crack initiation under dynamic or static loading. In the propagating and arresting cases the beneficial effct of overmatching of weld metal was found .However non significant effect of the weldmatch mg on the propagation thresholds △Kth and da'dN was found.
