In order to study influences of geometric parameters on the T-shaped components local loading process, a new mathematical model considering the fillet radius and draft angle was established by using the slab method. T...In order to study influences of geometric parameters on the T-shaped components local loading process, a new mathematical model considering the fillet radius and draft angle was established by using the slab method. The results obtained by the mathematical model agree with the data form experiment and numerical simulation, and the results are closer to the experimental and simulation results. The influence of draft angle may be neglected under the forming conditions used. The influence of fillet radius is notable, especially in the case that the ratio of fillet radius to rib width is less than 0.75.展开更多
A V-shaped bending device was established to evaluate the effects of temperature and bending fillet radius on springback behavior of 2219-W aluminum alloy at cryogenic temperatures.The cryogenic springback mechanism w...A V-shaped bending device was established to evaluate the effects of temperature and bending fillet radius on springback behavior of 2219-W aluminum alloy at cryogenic temperatures.The cryogenic springback mechanism was elucidated through mechanical analyses and numerical simulations.The results indicated that the springback angle at cryogenic temperatures was greater than that at room temperature.The springback angle increased further as the temperature returned to ambient conditions,attributed to the combined effects of the “dual enhancement effect” and thermal expansion.Notably,a critical fillet radius made the springback angle zero for 90° V-shaped bending.The critical fillet radius at cryogenic temperatures was smaller than that at room temperature,owing to the influence of temperature variations on the bending moment ratio between the forward bending section at the fillet and the reverse bending section of the straight arm.展开更多
目的:分析应用掌侧接骨板方法治疗桡骨远端die-punch骨折的临床可行性。方法:选取我院2014年12月~2015年12月已接受掌侧接骨板治疗的远端die-punch骨折患者32例为对象。32例患者的die-punch骨折类型主要有三种,为纵向劈裂类型、掌侧类...目的:分析应用掌侧接骨板方法治疗桡骨远端die-punch骨折的临床可行性。方法:选取我院2014年12月~2015年12月已接受掌侧接骨板治疗的远端die-punch骨折患者32例为对象。32例患者的die-punch骨折类型主要有三种,为纵向劈裂类型、掌侧类型、背侧类型。治疗所用的接骨板的类型为万向双柱锁定加压类型及2.4 mm T类型。患者手术后选择性进行一些功能恢复训练,如术后1个月内行手掌和指关节的活动,术后超1个月行腕关节活动训练。对32例患者进行随访,相关内容有X片、DASH评分、腕部是否出现畸形、并发症情况、握力、腕关节活动情况。探究采用不同die-punch骨折类类型和不同接骨板类型患者之间上述指标的差异。结果:成功随访了32例患者,经X片发现骨折愈合状况良好,且关节面也较为平整,未出现并发症和腕部畸形现象。不同die-punch骨折类型和不同接骨板类型患者DASH评分、握力、腕关节活动状况差异均无统计学意义(P>0.05)。结论:应用掌侧接骨板方法治疗桡骨远端die-punch骨折具有临床可行性。展开更多
基金Project (50935007) supported by the National Natural Science Foundation for Key Program of ChinaProject (2010CB731701) supported by the National Basic Research Program of ChinaProject (50905145) supported by the National Natural Science Foundation of China
文摘In order to study influences of geometric parameters on the T-shaped components local loading process, a new mathematical model considering the fillet radius and draft angle was established by using the slab method. The results obtained by the mathematical model agree with the data form experiment and numerical simulation, and the results are closer to the experimental and simulation results. The influence of draft angle may be neglected under the forming conditions used. The influence of fillet radius is notable, especially in the case that the ratio of fillet radius to rib width is less than 0.75.
基金the financial supports from the National Key Research and Development Program of China (No. 2019YFA0708804)。
文摘A V-shaped bending device was established to evaluate the effects of temperature and bending fillet radius on springback behavior of 2219-W aluminum alloy at cryogenic temperatures.The cryogenic springback mechanism was elucidated through mechanical analyses and numerical simulations.The results indicated that the springback angle at cryogenic temperatures was greater than that at room temperature.The springback angle increased further as the temperature returned to ambient conditions,attributed to the combined effects of the “dual enhancement effect” and thermal expansion.Notably,a critical fillet radius made the springback angle zero for 90° V-shaped bending.The critical fillet radius at cryogenic temperatures was smaller than that at room temperature,owing to the influence of temperature variations on the bending moment ratio between the forward bending section at the fillet and the reverse bending section of the straight arm.
文摘目的:分析应用掌侧接骨板方法治疗桡骨远端die-punch骨折的临床可行性。方法:选取我院2014年12月~2015年12月已接受掌侧接骨板治疗的远端die-punch骨折患者32例为对象。32例患者的die-punch骨折类型主要有三种,为纵向劈裂类型、掌侧类型、背侧类型。治疗所用的接骨板的类型为万向双柱锁定加压类型及2.4 mm T类型。患者手术后选择性进行一些功能恢复训练,如术后1个月内行手掌和指关节的活动,术后超1个月行腕关节活动训练。对32例患者进行随访,相关内容有X片、DASH评分、腕部是否出现畸形、并发症情况、握力、腕关节活动情况。探究采用不同die-punch骨折类类型和不同接骨板类型患者之间上述指标的差异。结果:成功随访了32例患者,经X片发现骨折愈合状况良好,且关节面也较为平整,未出现并发症和腕部畸形现象。不同die-punch骨折类型和不同接骨板类型患者DASH评分、握力、腕关节活动状况差异均无统计学意义(P>0.05)。结论:应用掌侧接骨板方法治疗桡骨远端die-punch骨折具有临床可行性。
