The mechanical properties of the monodirectional Gutou mortise-tenon joints of the ancient Chinese traditional timber buildings in the Yangtze River region were studied using the experimental method. Three monodirecti...The mechanical properties of the monodirectional Gutou mortise-tenon joints of the ancient Chinese traditional timber buildings in the Yangtze River region were studied using the experimental method. Three monodirectional Gutou mortise-tenon joints were designed according to the actual configurations. The failure modes,the hysteretic curves,the skeleton curves, the rotation rigidities, and the energy dissipation capacity of this type of mortise-tenon joints under the low cyclic reversed loading were obtained. The results show that the hysteretic curves of the monodirectional Gutou mortise-tenon joints appear to be Z shape and have obvious pinch effects. During the process of the test,these mortisetenon joints pass orderly through the elastic stage,the yield stage and the failure stage. The energy dissipation capacity of these mortise-tenon joints generally decreases with the increase in the rotation angle. The equivalent viscous damping coefficients of the monodirectional Gutou mortise-tenon joints are between 0. 161 and 0. 193. The results can provide the theoretical base for the computing analysis and repair design of Chinese traditional timber buildings in the Yangtze River region.展开更多
The mortise-tenon joint is an important hub transmitting and distributing external loads for load-bearing components(beams,columns et al.)in the ancient-timber frame structure system.However,the conventional steel hoo...The mortise-tenon joint is an important hub transmitting and distributing external loads for load-bearing components(beams,columns et al.)in the ancient-timber frame structure system.However,the conventional steel hoop reinforcement methods often insert wood screws into the timber components.When the reinforced joint rotates greatly,the anchoring failure of the screws will cause damage to the timber joint.To solve this problem,this study proposes a detachable and replaceable non-destructive flat-steel jacket reinforcement method in which horizontal flat steel is placed in the center of the joint,and the bolt is extended to the outside of the timber beam.Nine 1:3.52 scaled straight-tenon joint specimens were subjected to monotonic loading of beam ends,including three unreinforced reference joints,three joints with flat-steel jacket and three carbon fiber-reinforced plastic(CFRP)reinforced joints.The mechanical behaviors of the novel joints with flat-steel jacket were experimentally studied by comparing with those of the joints without strengthening and retrofitted with CFRP,based on the failure modes,the initial stiffness,the ultimate bearing capacity,and the moment-rotation relationship curves.Results indicated that the mortise-tenon joints reinforced with flat-steel jackets maintain the original semi-rigid properties of the unreinforced mortise-tenon joints and can effectively prevent the tenon from pulling out.The initial stiffness and ultimate bearing capacity were improved markedly.The column and beam of the reinforced joints remain intact providing the reference for the practical application of joints reinforcement.The mortisetenon joints reinforced with CFRP lose the semi-rigid properties of the unreinforced tenon-mortise joints.The joints reinforced with CFRP have the largest initial stiffness,while the unreinforced joints have the lowest stiffness.The initial stiffness of the proposed joint is in between the joints reinforced with CFRP and unreinforced joints.The ultimate bearing capacity of the joints reinforced with flat-steel jacket is larger than the other two joints,whereas the unreinforced joints have the lowest ultimate bearing capacity.展开更多
目的了解人工全膝关节置换术后1年以上老年骨性关节炎患者的生活质量,并分析其影响因素。方法采用一般情况调查表、美国纽约特种外科医院(Hospital for Special Surgery,HSS)的膝关节恢复评分表、健康状况调查问卷(SF-36)及社会支持评...目的了解人工全膝关节置换术后1年以上老年骨性关节炎患者的生活质量,并分析其影响因素。方法采用一般情况调查表、美国纽约特种外科医院(Hospital for Special Surgery,HSS)的膝关节恢复评分表、健康状况调查问卷(SF-36)及社会支持评定量表,对2009年5月至2011年5月哈尔滨医科大学附属第一临床医学院收治的150例人工全膝关节置换术后患者进行调查。结果人工膝关节置换术后患者的生活质量较正常人群低(均P<0.01);多元回归分析表明,患者在躯体健康方面的生活质量与年龄、其他疾病史呈负相关(P<0.05或P<0.01),与HSS评分呈正相关(P<0.05);在精神健康方面的生活质量与婚姻状况、家庭关系、经济收入、文化程度及社会支持利用度呈正相关(P<0.05或P<0.01)。结论人工膝关节置换术后患者的生活质量降低,应采取针对性的护理干预措施,同时提供有效的社会支持,进而提高其生活质量。展开更多
基金The National Natural Science Foundation of China(No.51138002,51578127)
文摘The mechanical properties of the monodirectional Gutou mortise-tenon joints of the ancient Chinese traditional timber buildings in the Yangtze River region were studied using the experimental method. Three monodirectional Gutou mortise-tenon joints were designed according to the actual configurations. The failure modes,the hysteretic curves,the skeleton curves, the rotation rigidities, and the energy dissipation capacity of this type of mortise-tenon joints under the low cyclic reversed loading were obtained. The results show that the hysteretic curves of the monodirectional Gutou mortise-tenon joints appear to be Z shape and have obvious pinch effects. During the process of the test,these mortisetenon joints pass orderly through the elastic stage,the yield stage and the failure stage. The energy dissipation capacity of these mortise-tenon joints generally decreases with the increase in the rotation angle. The equivalent viscous damping coefficients of the monodirectional Gutou mortise-tenon joints are between 0. 161 and 0. 193. The results can provide the theoretical base for the computing analysis and repair design of Chinese traditional timber buildings in the Yangtze River region.
基金This research was funded by the National Natural Science Foundation of China No.51908291Nanjing Forestry University Youth Science and Technology Innovation Fund No.CX2019002.
文摘The mortise-tenon joint is an important hub transmitting and distributing external loads for load-bearing components(beams,columns et al.)in the ancient-timber frame structure system.However,the conventional steel hoop reinforcement methods often insert wood screws into the timber components.When the reinforced joint rotates greatly,the anchoring failure of the screws will cause damage to the timber joint.To solve this problem,this study proposes a detachable and replaceable non-destructive flat-steel jacket reinforcement method in which horizontal flat steel is placed in the center of the joint,and the bolt is extended to the outside of the timber beam.Nine 1:3.52 scaled straight-tenon joint specimens were subjected to monotonic loading of beam ends,including three unreinforced reference joints,three joints with flat-steel jacket and three carbon fiber-reinforced plastic(CFRP)reinforced joints.The mechanical behaviors of the novel joints with flat-steel jacket were experimentally studied by comparing with those of the joints without strengthening and retrofitted with CFRP,based on the failure modes,the initial stiffness,the ultimate bearing capacity,and the moment-rotation relationship curves.Results indicated that the mortise-tenon joints reinforced with flat-steel jackets maintain the original semi-rigid properties of the unreinforced mortise-tenon joints and can effectively prevent the tenon from pulling out.The initial stiffness and ultimate bearing capacity were improved markedly.The column and beam of the reinforced joints remain intact providing the reference for the practical application of joints reinforcement.The mortisetenon joints reinforced with CFRP lose the semi-rigid properties of the unreinforced tenon-mortise joints.The joints reinforced with CFRP have the largest initial stiffness,while the unreinforced joints have the lowest stiffness.The initial stiffness of the proposed joint is in between the joints reinforced with CFRP and unreinforced joints.The ultimate bearing capacity of the joints reinforced with flat-steel jacket is larger than the other two joints,whereas the unreinforced joints have the lowest ultimate bearing capacity.
文摘目的了解人工全膝关节置换术后1年以上老年骨性关节炎患者的生活质量,并分析其影响因素。方法采用一般情况调查表、美国纽约特种外科医院(Hospital for Special Surgery,HSS)的膝关节恢复评分表、健康状况调查问卷(SF-36)及社会支持评定量表,对2009年5月至2011年5月哈尔滨医科大学附属第一临床医学院收治的150例人工全膝关节置换术后患者进行调查。结果人工膝关节置换术后患者的生活质量较正常人群低(均P<0.01);多元回归分析表明,患者在躯体健康方面的生活质量与年龄、其他疾病史呈负相关(P<0.05或P<0.01),与HSS评分呈正相关(P<0.05);在精神健康方面的生活质量与婚姻状况、家庭关系、经济收入、文化程度及社会支持利用度呈正相关(P<0.05或P<0.01)。结论人工膝关节置换术后患者的生活质量降低,应采取针对性的护理干预措施,同时提供有效的社会支持,进而提高其生活质量。
