An interaction function was constructed based on the axial compression/tension and shear loads of orthotropic plates.The coefficients of the polynomial function were determined by uniaxial test results.Buckling intera...An interaction function was constructed based on the axial compression/tension and shear loads of orthotropic plates.The coefficients of the polynomial function were determined by uniaxial test results.Buckling interaction and failure interaction formulae under combined axial tension/compression and shear loads were established.Based on the uniaxial load test results of orthotropic plates,the buckling load and bearing capacity under any proportion of the combined loads could be predicted by using the proposed interaction formulae.The buckling interaction curves and failure envelopes predicted by the proposed interaction formulae were in excellent agreement with the test results.展开更多
目的总结前后联合入路重建钛板内固定治疗复杂髋臼骨折的经验。方法对2005年2月～2009年3月应用髂腹股沟入路联合改良Gibson入路治疗29例复杂髋臼骨折的资料进行回顾性研究。结果术后患者均获随访，时间10～44个月，平均18个月。采用Ma...目的总结前后联合入路重建钛板内固定治疗复杂髋臼骨折的经验。方法对2005年2月～2009年3月应用髂腹股沟入路联合改良Gibson入路治疗29例复杂髋臼骨折的资料进行回顾性研究。结果术后患者均获随访，时间10～44个月，平均18个月。采用Matta的X线复位标准评定：解剖复位20例，满意复位5例，不满意复位4例，解剖复位率达69％；改良Merled’Aubigne and Postel髋关节评分标准评价术后功能：优6例，良19例，可3例，差1例，关节功能优良率86％；异位骨化3例，创伤性关节炎2例，股骨头坏死1例，无深部感染，无血管神经损伤。结论髂腹股沟入路联合改良Gibson入路治疗复杂髋臼骨折具有显露充分，固定牢靠，创伤较小，手术时间短，并发症少等优点，值得临床推广。展开更多
The evolution of wake structures and variation of the forces on a flat plate in harmonic oscillatory and in-line combined flows are obtained numerically by improved discrete vortex method. For the oscillatory oncoming...The evolution of wake structures and variation of the forces on a flat plate in harmonic oscillatory and in-line combined flows are obtained numerically by improved discrete vortex method. For the oscillatory oncoming flow cases, when K_c number varies from 2 to 40, the vortex pattern changes from a 'harmonic wave' shaped (in a range of small K_c numbers) to a slight inclined 'harmonic wave' shaped (in a range of moderate K_c numbers), then to inclined vortex clusters with an angle of 50 ° to the oncoming flow direction (at K_c = 20), at last, as K_c number becomes large, the vortex pattern is like a normal Karman vortex street. The well predicted drag and inertia force coefficients are obtained, which are more close to the results of Keulegan & Carpenter's experiment as compared with previous vortex simulation by other au- thors. The existence of minimum point of inertia force coefficient C_m near K_c = 20 is also well predicted and this phenomenon can be interpreted according to the vortex structure. For steady-oscillatory in-line combined flow cases, the vortex modes behave like a vortex street, exhibit a 'longitudinal wave' structure, and a vor- tex cluster shape corresponding to the ratios of U_m to U_0 which are of O (10^(-1)), O(1)and O (10), respectively. The effect on the prediction of forces on the flat plate from the disturbance component in a combined flow has been demon- strated qualitatively. In addition to this, the lock-in phenomenon of vortex shedding has been checked.展开更多
Numerical study on near wake flows of a flat plate in three kinds of oncoming flows is made by using the discrete vortex model and improved vorticity creation method. For steady oncoming flow, both gross and detailed ...Numerical study on near wake flows of a flat plate in three kinds of oncoming flows is made by using the discrete vortex model and improved vorticity creation method. For steady oncoming flow, both gross and detailed features of the wake flow are calculated and discussed. Then, in harmonic oscillatory oncoming flow two different wake flow patterns with K_c=2,4 and 10 are obtained respectively. Our results present a new wake flow pattern for low K_c numbers (K_c<5) describing vortex shedding, pairing and moving in a period of the oscillatory flow starting from rest. The calculated drag and inertia force coefficients are closer to experimental data from the U-tube than the previous results of vortex simulation. For in-line combined oncoming flow the vortex lock-in and dynamic characteristics are simulated. The results are shown to be in good agreement with experiments.展开更多
Objective:To compare the clinical therapeutic effect of bridge combined internal fixation system and locking compression plate internal fixation in the treatment of displaced midshaft clavicle fractures by emphaticall...Objective:To compare the clinical therapeutic effect of bridge combined internal fixation system and locking compression plate internal fixation in the treatment of displaced midshaft clavicle fractures by emphatically observing fracture healing and shoulder joint function.Methods:Totally 44 elderly patients with Robinson type 2B displaced midshaft clavicle fractures were included from the Department of Orthopaedics,Shenyang Fourth People's Hospital during February 2016 and December 2018,including 23 males and 21 females,mean age(69.8±10.2)years old.The patients were divided into a bridge combined internal fixation system group(bridge group,n=22)and a locking compression plate internal fixation group(plate group,n=22)according to the internal fixation methods.The operation time,intraoperative blood loss,fracture healing time,and postoperative complications were recorded.At 12 months after surgery,the shoulder joint Constant-Murley score and DASH score were used to assess the recovery of joint function.The serum levels of bone turnover biochemical markers procollagen I N-terminal peptide(P1NP),cross-linked Carboxy-terminal telopeptide of typeⅠcollagen(CTX-I),and osteoblast specific factor(OSF)were measured before and 3 months after surgery.Results:The operation time,intraoperative blood loss and fracture healing time of the bridge group were significantly shorter than those of the plate group(P<0.05).Constant scores and DASH scores in the bridge group were significantly better than those of the plate group at 12 months after surgery(P<0.05).Serum levels of CTX-I was significantly decreased,while the P1NP and OSF were significantly increased compared with before surgery in the both groups(P<0.05),and the changes were more obvious in the bridge group(P<0.05).The incidence of complications was similar between the two groups(P<0.05).Conclusion:Compared with the locking plate system,the bridge combined internal fixation system can effectively improve the operation efficiency,have more benefits on fracture healing,be展开更多
文摘An interaction function was constructed based on the axial compression/tension and shear loads of orthotropic plates.The coefficients of the polynomial function were determined by uniaxial test results.Buckling interaction and failure interaction formulae under combined axial tension/compression and shear loads were established.Based on the uniaxial load test results of orthotropic plates,the buckling load and bearing capacity under any proportion of the combined loads could be predicted by using the proposed interaction formulae.The buckling interaction curves and failure envelopes predicted by the proposed interaction formulae were in excellent agreement with the test results.
文摘目的总结前后联合入路重建钛板内固定治疗复杂髋臼骨折的经验。方法对2005年2月～2009年3月应用髂腹股沟入路联合改良Gibson入路治疗29例复杂髋臼骨折的资料进行回顾性研究。结果术后患者均获随访，时间10～44个月，平均18个月。采用Matta的X线复位标准评定：解剖复位20例，满意复位5例，不满意复位4例，解剖复位率达69％；改良Merled’Aubigne and Postel髋关节评分标准评价术后功能：优6例，良19例，可3例，差1例，关节功能优良率86％；异位骨化3例，创伤性关节炎2例，股骨头坏死1例，无深部感染，无血管神经损伤。结论髂腹股沟入路联合改良Gibson入路治疗复杂髋臼骨折具有显露充分，固定牢靠，创伤较小，手术时间短，并发症少等优点，值得临床推广。
基金The project supported by National Natural Science Foundation of China & LNM, Institute of Mechanics, CAS
文摘The evolution of wake structures and variation of the forces on a flat plate in harmonic oscillatory and in-line combined flows are obtained numerically by improved discrete vortex method. For the oscillatory oncoming flow cases, when K_c number varies from 2 to 40, the vortex pattern changes from a 'harmonic wave' shaped (in a range of small K_c numbers) to a slight inclined 'harmonic wave' shaped (in a range of moderate K_c numbers), then to inclined vortex clusters with an angle of 50 ° to the oncoming flow direction (at K_c = 20), at last, as K_c number becomes large, the vortex pattern is like a normal Karman vortex street. The well predicted drag and inertia force coefficients are obtained, which are more close to the results of Keulegan & Carpenter's experiment as compared with previous vortex simulation by other au- thors. The existence of minimum point of inertia force coefficient C_m near K_c = 20 is also well predicted and this phenomenon can be interpreted according to the vortex structure. For steady-oscillatory in-line combined flow cases, the vortex modes behave like a vortex street, exhibit a 'longitudinal wave' structure, and a vor- tex cluster shape corresponding to the ratios of U_m to U_0 which are of O (10^(-1)), O(1)and O (10), respectively. The effect on the prediction of forces on the flat plate from the disturbance component in a combined flow has been demon- strated qualitatively. In addition to this, the lock-in phenomenon of vortex shedding has been checked.
基金The project supported by National Natural Science Fundation of China and LNM of Institute of Mechanics. CAS .
文摘Numerical study on near wake flows of a flat plate in three kinds of oncoming flows is made by using the discrete vortex model and improved vorticity creation method. For steady oncoming flow, both gross and detailed features of the wake flow are calculated and discussed. Then, in harmonic oscillatory oncoming flow two different wake flow patterns with K_c=2,4 and 10 are obtained respectively. Our results present a new wake flow pattern for low K_c numbers (K_c<5) describing vortex shedding, pairing and moving in a period of the oscillatory flow starting from rest. The calculated drag and inertia force coefficients are closer to experimental data from the U-tube than the previous results of vortex simulation. For in-line combined oncoming flow the vortex lock-in and dynamic characteristics are simulated. The results are shown to be in good agreement with experiments.
文摘Objective:To compare the clinical therapeutic effect of bridge combined internal fixation system and locking compression plate internal fixation in the treatment of displaced midshaft clavicle fractures by emphatically observing fracture healing and shoulder joint function.Methods:Totally 44 elderly patients with Robinson type 2B displaced midshaft clavicle fractures were included from the Department of Orthopaedics,Shenyang Fourth People's Hospital during February 2016 and December 2018,including 23 males and 21 females,mean age(69.8±10.2)years old.The patients were divided into a bridge combined internal fixation system group(bridge group,n=22)and a locking compression plate internal fixation group(plate group,n=22)according to the internal fixation methods.The operation time,intraoperative blood loss,fracture healing time,and postoperative complications were recorded.At 12 months after surgery,the shoulder joint Constant-Murley score and DASH score were used to assess the recovery of joint function.The serum levels of bone turnover biochemical markers procollagen I N-terminal peptide(P1NP),cross-linked Carboxy-terminal telopeptide of typeⅠcollagen(CTX-I),and osteoblast specific factor(OSF)were measured before and 3 months after surgery.Results:The operation time,intraoperative blood loss and fracture healing time of the bridge group were significantly shorter than those of the plate group(P<0.05).Constant scores and DASH scores in the bridge group were significantly better than those of the plate group at 12 months after surgery(P<0.05).Serum levels of CTX-I was significantly decreased,while the P1NP and OSF were significantly increased compared with before surgery in the both groups(P<0.05),and the changes were more obvious in the bridge group(P<0.05).The incidence of complications was similar between the two groups(P<0.05).Conclusion:Compared with the locking plate system,the bridge combined internal fixation system can effectively improve the operation efficiency,have more benefits on fracture healing,be
