A single three point bend specimen compliance method for determining JIC of high strength high fracture toughness steels is presented and a formula for calculatinff J-integral is proposed as follows.It is simple and v...A single three point bend specimen compliance method for determining JIC of high strength high fracture toughness steels is presented and a formula for calculatinff J-integral is proposed as follows.It is simple and valid for high strength high fracture toughness steels. The values of JIC and KIC measured by this method are in good agreement with those measured by standard test method.展开更多
This paper presents a precise solution to predict the behavior of steel fiber reinforced concrete(SFRC) under the four point bending test(FPBT).All the force components at the beam section(before and after cracking) a...This paper presents a precise solution to predict the behavior of steel fiber reinforced concrete(SFRC) under the four point bending test(FPBT).All the force components at the beam section(before and after cracking) are formulated by applying these assumptions:a realistic stress-strain model is used for concrete behavior in compression,a linear response is considered for the uncracked tension region in a concrete constitutive model,and an exponential relationship is proposed as a stress-crack opening in the crack region which requires two parameters.Then the moment capacity of the critical cracked section is calculated by using these forces and satisfying equilibrium law at the section.Parametric studies are done on the behavior of SFRC to assess the sensitivity of the solution.Finally,this solution is validated with some existing experimental data.The result shows the proposed solution is able to estimate the behavior of SFRC under FPBT.展开更多
304 stainless steel coating was deposited on the Interstitial-Free steel substrate by cold gas dynamic spraying （CGDS）. Three-point bending test of the cold sprayed 304 stainless steel coating was tested by SHIMADZU...304 stainless steel coating was deposited on the Interstitial-Free steel substrate by cold gas dynamic spraying （CGDS）. Three-point bending test of the cold sprayed 304 stainless steel coating was tested by SHIMADZU electro-hydraulic servo-controlled fatigue testing machine and the fracture morphology was examined by scanning electron microscopy. The results showed that the fracture behavior of the cold sprayed 304 stainless steel coating was brittleness fracture. The crack in the coating occurred in the interfaces between particles and the crack extended to the internal of the coating with the increase of the load. When the crack has extended to the combination interface between coating and substrate, the crack extended to the two sides. The microstructure and mechanical property of the cold sprayed 304 stainless steel coating have been optimized after heat treatment.展开更多
Objective: To assess the effect of Danshen 9403 (DS 9403), an effective fraction of Radix Salviae miltiorrhizae (RSM) on healing of bone fracture. Methods: Standardized radial fracture was performed in 120 Wistar ra...Objective: To assess the effect of Danshen 9403 (DS 9403), an effective fraction of Radix Salviae miltiorrhizae (RSM) on healing of bone fracture. Methods: Standardized radial fracture was performed in 120 Wistar rats. The model rats were randomized into four groups: Group A was fed with DS 9403, group B injected with Staphylococcus aureus , group C with normal saline administration, and group D with RSM injection. The treatment began at the first day of fracture. The rats were sacrificed on the day 25, 39 and 50 separately in batches and their intact radii were removed by dissection for detecting load and stress of three point bending test with autograph universal material testing machine (Shimazu, Japan). Results: The parameters of load in DS 9403 treated group on the 39th day and that of stress at 25th, 39th and 50th day were (6.20±1.32)N, (5.71±3.58)N/mm 2, (8.27±2.42)N/mm 2 and (66.25±26.21)N/mm 2 respectively, which were significantly higher than those in other groups, P <0.05. Conclusion: DS 9403 has the action of increasing the strength of fracture broken end.展开更多
文摘A single three point bend specimen compliance method for determining JIC of high strength high fracture toughness steels is presented and a formula for calculatinff J-integral is proposed as follows.It is simple and valid for high strength high fracture toughness steels. The values of JIC and KIC measured by this method are in good agreement with those measured by standard test method.
文摘This paper presents a precise solution to predict the behavior of steel fiber reinforced concrete(SFRC) under the four point bending test(FPBT).All the force components at the beam section(before and after cracking) are formulated by applying these assumptions:a realistic stress-strain model is used for concrete behavior in compression,a linear response is considered for the uncracked tension region in a concrete constitutive model,and an exponential relationship is proposed as a stress-crack opening in the crack region which requires two parameters.Then the moment capacity of the critical cracked section is calculated by using these forces and satisfying equilibrium law at the section.Parametric studies are done on the behavior of SFRC to assess the sensitivity of the solution.Finally,this solution is validated with some existing experimental data.The result shows the proposed solution is able to estimate the behavior of SFRC under FPBT.
基金the support of the BaoShan Iron and Steel Company Limited
文摘304 stainless steel coating was deposited on the Interstitial-Free steel substrate by cold gas dynamic spraying （CGDS）. Three-point bending test of the cold sprayed 304 stainless steel coating was tested by SHIMADZU electro-hydraulic servo-controlled fatigue testing machine and the fracture morphology was examined by scanning electron microscopy. The results showed that the fracture behavior of the cold sprayed 304 stainless steel coating was brittleness fracture. The crack in the coating occurred in the interfaces between particles and the crack extended to the internal of the coating with the increase of the load. When the crack has extended to the combination interface between coating and substrate, the crack extended to the two sides. The microstructure and mechanical property of the cold sprayed 304 stainless steel coating have been optimized after heat treatment.
文摘Objective: To assess the effect of Danshen 9403 (DS 9403), an effective fraction of Radix Salviae miltiorrhizae (RSM) on healing of bone fracture. Methods: Standardized radial fracture was performed in 120 Wistar rats. The model rats were randomized into four groups: Group A was fed with DS 9403, group B injected with Staphylococcus aureus , group C with normal saline administration, and group D with RSM injection. The treatment began at the first day of fracture. The rats were sacrificed on the day 25, 39 and 50 separately in batches and their intact radii were removed by dissection for detecting load and stress of three point bending test with autograph universal material testing machine (Shimazu, Japan). Results: The parameters of load in DS 9403 treated group on the 39th day and that of stress at 25th, 39th and 50th day were (6.20±1.32)N, (5.71±3.58)N/mm 2, (8.27±2.42)N/mm 2 and (66.25±26.21)N/mm 2 respectively, which were significantly higher than those in other groups, P <0.05. Conclusion: DS 9403 has the action of increasing the strength of fracture broken end.
