In order to establish the design method for T-shaped tensile connector with high strength bolt,the theoretical analysis is carried out. Firstly,it analyzes the performance of the connector and establishes prying force...In order to establish the design method for T-shaped tensile connector with high strength bolt,the theoretical analysis is carried out. Firstly,it analyzes the performance of the connector and establishes prying force calculation model. Based on the model,prying force equation and function between bolt prying force and flange thickness is derived,and the min and max thickness requirement of flange plate under a certain tension load is then obtained. Finally,two simplified design methods of the connector are proposed,which are bolt pulling capacity method and flange plate bending capacity method.展开更多
Steel connection design using pre-tensioned bolts depends significantly on the value of the Prying forces exerted from the end plate. The Egyptian Code ECP （205） suggested a formula that can determine the Prying for...Steel connection design using pre-tensioned bolts depends significantly on the value of the Prying forces exerted from the end plate. The Egyptian Code ECP （205） suggested a formula that can determine the Prying force value. In this research, the Prying force is numerically computed in a T-Stub connection using nonlinear finite element techniques. The model uses plane stress four node elements with two degrees of freedom per node to simulate the flange of the T-Stub. The bolts are simulated using a truss element with large deformation capability to allow modeling of the pretension force. Surface to surface gap elements are used in order to simulate the contact between the T-Stub and the supporting element. Parametric study on the end plate thickness, bolt size, bolt arrangement and pretension forces is performed in order to calibrate the Code formula. The parametric study covers all the practical ranges of the variables. The study revealed that the Code formula, inaccurately, determines the Prying force in a certain range. Moreover, a new equation for the prying force is developed using regression analysis on the finite element results.展开更多
目的:探讨空心顶棒复位与传统骨拨撬拨切开复位内固定术(Open reduction and Internal Fixation,ORIF)治疗胫骨平台骨折的临床疗效。方法:本研究为回顾性分析,选择通用环球中铁邳州医院2023年1月至2024年6月期间收治的70例胫骨平台骨折...目的:探讨空心顶棒复位与传统骨拨撬拨切开复位内固定术(Open reduction and Internal Fixation,ORIF)治疗胫骨平台骨折的临床疗效。方法:本研究为回顾性分析,选择通用环球中铁邳州医院2023年1月至2024年6月期间收治的70例胫骨平台骨折患者,所有患者均接受锁定钢板固定治疗。根据手术方式将其分为参照组(传统骨拨撬拨ORIF,37例)和试验组(空心顶棒复位固定,33例)。比较两组的围手术期参数(术中出血量、手术总时长、术后完全负重时间、住院时间)、功能康复指标[膝关节活动度、美国特种外科医院(Hospital for Special Surgery,HSS)评分和Lysholm功能评分、Rasmussen功能评分]及术后并发症。结果:与参照组相比,试验组的住院时间、手术总时长、术后完全负重时间更短,术中出血量更少,优良率更高,屈膝最大角度更大,而伸膝最大角度更小(P<0.05)。与参照组术后6个月相比,试验组HSS评分和Lysholm功能评分更高(P<0.05)。两组并发症发生率对比未见差异(P>0.05)。结论:相比于传统骨拨撬拨ORIF,空心顶棒复位治疗胫骨平台骨折,优势较为显著,可缩短手术总时长、住院时间,减少术中出血量,改善膝关节活动度和膝关节功能,安全性好。展开更多
基金Sponsored by the National Natural Science Foundation of China(Grant No.51408620)the Major Science and Technology Project during the Third Five-Year Plan Period of China MCC(Grant No.0012013010)
文摘In order to establish the design method for T-shaped tensile connector with high strength bolt,the theoretical analysis is carried out. Firstly,it analyzes the performance of the connector and establishes prying force calculation model. Based on the model,prying force equation and function between bolt prying force and flange thickness is derived,and the min and max thickness requirement of flange plate under a certain tension load is then obtained. Finally,two simplified design methods of the connector are proposed,which are bolt pulling capacity method and flange plate bending capacity method.
文摘Steel connection design using pre-tensioned bolts depends significantly on the value of the Prying forces exerted from the end plate. The Egyptian Code ECP （205） suggested a formula that can determine the Prying force value. In this research, the Prying force is numerically computed in a T-Stub connection using nonlinear finite element techniques. The model uses plane stress four node elements with two degrees of freedom per node to simulate the flange of the T-Stub. The bolts are simulated using a truss element with large deformation capability to allow modeling of the pretension force. Surface to surface gap elements are used in order to simulate the contact between the T-Stub and the supporting element. Parametric study on the end plate thickness, bolt size, bolt arrangement and pretension forces is performed in order to calibrate the Code formula. The parametric study covers all the practical ranges of the variables. The study revealed that the Code formula, inaccurately, determines the Prying force in a certain range. Moreover, a new equation for the prying force is developed using regression analysis on the finite element results.
文摘目的:探讨空心顶棒复位与传统骨拨撬拨切开复位内固定术(Open reduction and Internal Fixation,ORIF)治疗胫骨平台骨折的临床疗效。方法:本研究为回顾性分析,选择通用环球中铁邳州医院2023年1月至2024年6月期间收治的70例胫骨平台骨折患者,所有患者均接受锁定钢板固定治疗。根据手术方式将其分为参照组(传统骨拨撬拨ORIF,37例)和试验组(空心顶棒复位固定,33例)。比较两组的围手术期参数(术中出血量、手术总时长、术后完全负重时间、住院时间)、功能康复指标[膝关节活动度、美国特种外科医院(Hospital for Special Surgery,HSS)评分和Lysholm功能评分、Rasmussen功能评分]及术后并发症。结果:与参照组相比,试验组的住院时间、手术总时长、术后完全负重时间更短,术中出血量更少,优良率更高,屈膝最大角度更大,而伸膝最大角度更小(P<0.05)。与参照组术后6个月相比,试验组HSS评分和Lysholm功能评分更高(P<0.05)。两组并发症发生率对比未见差异(P>0.05)。结论:相比于传统骨拨撬拨ORIF,空心顶棒复位治疗胫骨平台骨折,优势较为显著,可缩短手术总时长、住院时间,减少术中出血量,改善膝关节活动度和膝关节功能,安全性好。
