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Effect of an Airbag-selective Portal Vein Blood Arrester on the Liver after Hepatectomy:A New Technique for Selective Clamping of the Portal Vein
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作者 Ce-xiong FU Xiao-ri QIN +6 位作者 Jin-song CHEN Jie ZHONG Yu-xu XIE Bi-dan LI Qing-qing FU Fang LI Jin-fang ZHENG 《Current Medical Science》 SCIE CAS 2024年第2期380-390,共11页
Objective:A novel technique was explored using an airbag-selective portal vein blood arrester that circumvents the need for an intraoperative assessment of anatomical variations in patients with complex intrahepatic s... Objective:A novel technique was explored using an airbag-selective portal vein blood arrester that circumvents the need for an intraoperative assessment of anatomical variations in patients with complex intrahepatic space-occupying lesions.Methods:Rabbits undergoing hepatectomy were randomly assigned to 4 groups:intermittent portal triad clamping(PTC),intermittent portal vein clamping(PVC),intermittent portal vein blocker with an airbag-selective portal vein blood arrester(APC),and without portal blood occlusion(control).Hepatic ischemia and reperfusion injury were assessed by measuring the 7-day survival rate,blood loss,liver function,hepatic pathology,hepatic inflammatory cytokine infiltration,hepatic malondialdehyde levels,and proliferating cell nuclear antigen levels.Results:Liver damage was substantially reduced in the APC and PVC groups.The APC animals exhibited transaminase levels similar to or less oxidative stress damage and inflammatory hepatocellular injury compared to those exhibited by the PVC animals.Bleeding was significantly higher in the control group than in the other groups.The APC group had less bleeding than the PVC group because of the avoidance of portal vein skeletonization during hepatectomy.Thus,more operative time was saved in the APC group than in the PVC group.Moreover,the total 7-day survival rate in the APC group was higher than that in the PTC group.Conclusion:Airbag-selective portal vein blood arresters may help protect against hepatic ischemia and reperfusion injury in rabbits undergoing partial hepatectomy.This technique may also help prevent liver damage in patients requiring hepatectomy. 展开更多
关键词 HEPATECTOMY portal vein hepatic damage selective clamping
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Resilient performance of self-centering hybrid rocking walls with curved interface under pseudo-static loading
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作者 Su Xing Yan Shi +1 位作者 Sun Xianglei Wang Tao 《Earthquake Engineering and Engineering Vibration》 SCIE EI CSCD 2024年第1期65-85,共21页
Frame and rocking wall(FRW)structures have excellent resilient performance during earthquakes.However,the concrete at interfacial corners of rocking walls(RWs)is easily crushed due to local extreme compression during ... Frame and rocking wall(FRW)structures have excellent resilient performance during earthquakes.However,the concrete at interfacial corners of rocking walls(RWs)is easily crushed due to local extreme compression during the rocking process.An innovative RW with a curved interface is proposed to prevent interfacial corners from producing local damage,enhancing its earthquake resilient performance(ERP).The precast wall panel with a curved interface is assembled into an integral self-centering hybrid rocking wall(SCRW)by two post-tensioned unbonded prestressed tendons.Moreover,two ordinary energy dissipation steel rebars and two shear reinforcements are arranged to increase the energy dissipation capacity and lateral resistance.Two SCRW specimens and one monolithic reinforced concrete(RC)shear wall(SW)were tested under pseudo-static loading to compare the ERPs of the proposed SCRW and the SW,focusing on studying the effect of the curved interface on the SCRW.The key resilient performance of rocking effects,failure modes,and hysteretic properties of the SCRW were explored.The results show that nonlinear deformations of the SCRW are concentrated along the interface between the SCRW and the foundation,avoiding damage within the SCRW.The restoring force provided by the prestressed tendons can effectively realize self-centering capacity with small residual deformation,and the resilient performance of the SCRW is better than that of monolithic SW.In addition,the curved interface of the SCRW makes the rocking center change and move inward,partially relieving the stress concentration and crush of concrete.The rocking range of the rocking center is about 41.4%of the width of the SCRW. 展开更多
关键词 self-centering hybrid rocking wall(SCRW) monolithic shear wall(SW) earthquake resilient performance(ERP) curved interface rocking center
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Comparison of nonlinear modeling methods for the composite rubber clamp
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作者 Yiming CAO Hui MA +4 位作者 Xumin GUO Bingfeng ZHAO Hui LI Xin WANG Bing WANG 《Applied Mathematics and Mechanics(English Edition)》 SCIE EI CSCD 2024年第5期763-778,共16页
The cubic stiffness force model(CSFM)and Bouc-Wen model(BWM)are introduced and compared innovatively.The unknown coefficients of the nonlinear models are identified by the genetic algorithm combined with experiments.B... The cubic stiffness force model(CSFM)and Bouc-Wen model(BWM)are introduced and compared innovatively.The unknown coefficients of the nonlinear models are identified by the genetic algorithm combined with experiments.By fitting the identified nonlinear coefficients under different excitation amplitudes,the nonlinear vibration responses of the system are predicted.The results show that the accuracy of the BWM is higher than that of the CSFM,especially in the non-resonant region.However,the optimization time of the BWM is longer than that of the CSFM. 展开更多
关键词 pipeline system nonlinear clamp model composite rubber clamp amplitude-dependent characteristic vibration response experiment
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Plastic Mechanism of Multi-pass Double-roller Clamping Spinning for Arc-shaped Surface Flange 被引量:3
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作者 FAN Shuqin ZHAO Shengdun +1 位作者 ZHANG Qi LI Yongyi 《Chinese Journal of Mechanical Engineering》 SCIE EI CAS CSCD 2013年第6期1127-1137,共11页
Compared with the conventional single-roller spinning process, the double-roller clamping spinning(DRCS) process can effectively prevent the sheet metal surface wrinkling and improve the the production efficiency an... Compared with the conventional single-roller spinning process, the double-roller clamping spinning(DRCS) process can effectively prevent the sheet metal surface wrinkling and improve the the production efficiency and the shape precision of final spun part. Based on ABAQUS/Explicit nonlinear finite element software, the finite element model of the multi-pass DRCS for the sheet metal is established, and the material model, the contact definition, the mesh generation, the loading trajectory and other key technical problems are solved. The simulations on the multi-pass DRCS of the ordinary Q235A steel cylindrical part with the arc-shaped surface flange are carried out. The effects of number of spinning passes on the production efficiency, the spinning moment, the shape error of the workpiece, and the wall thickness distribution of the final part are obtained. It is indicated definitely that with the increase of the number of spinning passes the geometrical precision of the spun part increases while the production efficiency reduces. Moreover, the variations of the spinning forces and the distributions of the stresses, strains, wall thickness during the multi-pass DRCS process are revealed. It is indicated that during the DRCS process the radical force is the largest, and the whole deformation area shows the tangential tensile strain and the radial compressive strain, while the thickness strain changes along the generatrix directions from the compressive strain on the outer edge of the flange to the tensile strain on the inner edge of the flange. Based on the G-CNC6135 NC lathe, the three-axis linkage computer-controlled experimental device for DRCS which is driven by the AC servo motor is developed. And then using the experimental device, the Q235A cylindrical parts with the arc-shape surface flange are formed by the DRCS. The simulation results of spun parts have good consistency with the experimental results, which verifies the feasibility of DRCS process and the reliability of the finite element model for DRCS. 展开更多
关键词 SPINNING double-roller clamping MULTI-PASS arc-shaped surface
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Test and simulation of full-scale self-centering beam-to-column connection 被引量:8
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作者 Deng Kailai Pan Peng +2 位作者 Alexandre Lam Pan Zhenhua Ye Lieping 《Earthquake Engineering and Engineering Vibration》 SCIE EI CSCD 2013年第4期599-607,共9页
A new type of beam-to-column connection for steel moment flames, designated as a "self-centering connection," is studied. In this connection, bolted top-and-seat angles, and post-tensioned (PT) high-strength steel... A new type of beam-to-column connection for steel moment flames, designated as a "self-centering connection," is studied. In this connection, bolted top-and-seat angles, and post-tensioned (PT) high-strength steel strands running along the beam are used. The PT strands tie the beam flanges on the column flange to resist moment and provide self-centering force. After an earthquake, the connections have zero deformation, and can be restored to their original status by simply replacing the angles. Four full-scale connections were tested under cyclic loading. The strength, energy-dissipation capacity, hysteresis curve, as well as angles and PT strands behavior of the connections are investigated. A general FEM analysis program called ABAQUS 6.9 is adopted to model the four test specimens. The numerical and test results match very well. Both the test and analysis results suggest that: (1) the columns and beams remain elastic while the angles sustain plastic deformations for energy dissipation when the rotation of the beam related to the column equals 0.05 tad, (2) the energy dissipation capacity is enhanced when the thickness of the angle is increased, and (3) the number of PT strands has a significant influence on the behavior of the connections, whereas the distance between the strands is not as important to the performance of the connection. 展开更多
关键词 steel frame CONNECTION ANGLE post-tensioned prestressing self-centering
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Shake-table testing of a self-centering precast reinforced concrete frame with shear walls 被引量:10
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作者 Lu Xilin Yang Boya Zhao Bin 《Earthquake Engineering and Engineering Vibration》 SCIE EI CSCD 2018年第2期221-233,共13页
The seismic performance of a self-centering precast reinforced concrete (RC) frame with shear walls was investigated in this paper. The lateral force resistance was provided by self-centering precast RC shear walls ... The seismic performance of a self-centering precast reinforced concrete (RC) frame with shear walls was investigated in this paper. The lateral force resistance was provided by self-centering precast RC shear walls (SPCW), which utilize a combination ofunbonded prestressed post-tensioned (PT) tendons and mild steel reinforcing bars for flexural resistance across base joints. The structures concentrated deformations at the bottom joints and the unbonded PT tendons provided the self-centering restoring force. A 1/3-scale model of a five-story self-centering RC frame with shear walls was designed and tested on a shake-table under a series of bi-directional earthquake excitations with increasing intensity. The acceleration response, roof displacement, inter-story drifts, residual drifts, shear force ratios, hysteresis curves, and local behaviour of the test specimen were analysed and evaluated. The results demonstrated that seismic performance of the test specimen was satisfactory in the plane of the shear wall; however, the structure sustained inter-story drift levels up to 2.45%. Negligible residual drifts were recorded after all applied earthquake excitations. Based on the shake-table test results, it is feasible to apply and popularize a self-centering precast RC frame with shear walls as a structural system in seismic regions. 展开更多
关键词 self-centering shake-table test RC frame with shear walls PRECAST unbonded post-tensioning seismicperformance
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Numerical simulation of horizontal transversal displacement under different fixed clamping force of welding fixture for superalloy during TIG welding 被引量:3
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作者 Zhang Wenyang Guo Shaoqing +2 位作者 Yuan Zhongjin Tang Siyi Liang Jiayu 《China Welding》 EI CAS 2018年第2期19-23,共5页
A numerical model is established by Abaqus software for superalloy during tungsten inert gas (TIG) welding with welding fixture to simulate the weld temperature filed, stress and strain field, and weld plate's hori... A numerical model is established by Abaqus software for superalloy during tungsten inert gas (TIG) welding with welding fixture to simulate the weld temperature filed, stress and strain field, and weld plate's horizontal trasnsveral shift. The clamp force perpendicular to the weld plate varying with welding time was analyzed. The maximum clamp force during welding process was calculated. Under the condition of insufficient of clamping force, a half or one third of the maximum clamp force for example, the weld plate's horizontal transversal displacement could happen and also be computed. 展开更多
关键词 TIC welding welding fixture clamping force transverse displacement finite element method
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Self-centering seismic retrofit scheme for reinforced concrete frame structures:SDOF system study 被引量:5
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作者 Yunfeng Zhang and Xiaobin Hu Department of Civil and Environmental Engineering,University of Maryland,College Park,MD 20742,USA 《Earthquake Engineering and Engineering Vibration》 SCIE EI CSCD 2010年第2期271-283,共13页
This paper presents the results of a parametric study of self-centering seismic retrofit schemes for reinforced concrete (RC) frame buildings. The self-centering retrofit system features flag-shaped hysteresis and min... This paper presents the results of a parametric study of self-centering seismic retrofit schemes for reinforced concrete (RC) frame buildings. The self-centering retrofit system features flag-shaped hysteresis and minimal residual deformation. For comparison purpose,an alternate seismic retrofit scheme that uses a bilinear-hysteresis retrofit system such as buckling-restrained braces (BRB) is also considered in this paper. The parametric study was carried out in a single-degree-of-freedom (SDOF) system framework since a multi-story building structure may be idealized as an equivalent SDOF system and investigation of the performance of this equivalent SDOF system can provide insight into the seismic response of the multi-story building. A peak-oriented hysteresis model which can consider the strength and stiffness degradation is used to describe the hysteretic behavior of RC structures. The parametric study involves two key parameters -the strength ratio and elastic stiffness ratio between the seismic retrofit system and the original RC frame. An ensemble of 172 earthquake ground motion records scaled to the design basis earthquake in California with a probability of exceedance of 10% in 50 years was constructed for the simulation-based parametric study. The effectiveness of the two seismic retrofit schemes considered in this study is evaluated in terms of peak displacement ratio,peak acceleration ratio,energy dissipation demand ratio and residual displacement ratio between the SDOF systems with and without retrofit. It is found from this parametric study that RC structures retrofitted with the self-centering retrofit scheme (SCRS) can achieve a seismic performance level comparable to the bilinear-hysteresis retrofit scheme (BHRS) in terms of peak displacement and energy dissipation demand ratio while having negligible residual displacement after earthquake. 展开更多
关键词 EARTHQUAKE reinforced concrete frame structure nonlinear analysis SDOF system seismic retrofit self-centering
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Minimum Normal Force Principle Based Quantitive Optimization of Clamping Forces for Thin Walled Part 被引量:2
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作者 张发平 孙厚芳 SHAHIDI.Butt 《Journal of Beijing Institute of Technology》 EI CAS 2008年第2期148-152,共5页
Based on the stability criteria of workpiece-fixture system, quantitative optimization of clamping forces during precise machining process for thin walled part is studied considering the contact condition between wokp... Based on the stability criteria of workpiece-fixture system, quantitative optimization of clamping forces during precise machining process for thin walled part is studied considering the contact condition between wokpiece and locator, the contact mechanical model is achieved, which is further been used to calculate the entire passive forces acting on the statically undetermined workpiece by means of the force screw theory as well as minimum norm force principle. Furthermore, a new methodology to optimize clamping forces is put forward, on the criteria of keeping the stability of workpiece during cutting process. By this way, the intensity of clamping forces is decreased dramatically, which will be most beneficial for improving the machining quality of thin-walled parts. Finally, a case study is used to support and validate the proposed model. 展开更多
关键词 workpiece-fixture system stability minimum norm force principle clamping forces optimization
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Tepid antegrade intermittent blood cardioplegia as an alternative for intermittent crossclamping with Lidoflazine 被引量:3
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作者 Sofia Kalantary Anouk de Bruyn +1 位作者 Steven Laga Inez Rodrigus 《World Journal of Cardiovascular Diseases》 2013年第7期454-457,共4页
Background: Blood cardioplegia is a technique with many variations in its use. Intermittent cross clamping with Lidoflazine has proven to deliver good cardioprotection in our center. Question: Is tepid (32°C) ant... Background: Blood cardioplegia is a technique with many variations in its use. Intermittent cross clamping with Lidoflazine has proven to deliver good cardioprotection in our center. Question: Is tepid (32°C) antegrade intermittent blood cardioplegia an efficient, safe and easy-to-use alternative to intermittent cross-clamping with Lidoflazine in elective isolated CABG in low-risk patients? Primary outcomes are heart enzymes (cTnI, CK-MB). Secondary outcomes are operation times, length of hospital stay, major complications and in-hospital mortality. Methods: From January 2012 until November 2012, 40 patients with LVEF ≥50%, EuroSCORE 展开更多
关键词 BLOOD CARDIOPLEGIA INTERMITTENT Cross clamping Lidoflazine MYOCARDIAL Protection
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STRENGTH ANALYSIS OF CLAMPING IN MICRO/NANO SCALE EXPERIMENTS 被引量:2
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作者 Liang Liu Dujuan Zeng +2 位作者 Xianlong Wei Qing Chen Xide Li 《Acta Mechanica Solida Sinica》 SCIE EI 2009年第6期584-592,共9页
Two kinds of clamping in micro/nano scale experiments are investigated in this paper, one based on electron-beam-induced deposition, and the other on the van der Waals interaction. The clamping strength and mechanism ... Two kinds of clamping in micro/nano scale experiments are investigated in this paper, one based on electron-beam-induced deposition, and the other on the van der Waals interaction. The clamping strength and mechanism are analyzed both theoretically and experimentally. The influence of relative humidity on the micro/nano clamping and the method of electrostatic clamping are discussed. The clamping strength and performance of different clamping methods are compared considering the size and material of the clamped objects, and the application environments. 展开更多
关键词 micro/nano experimental mechanics clamping interracial strength electron-beaminduced deposition (EBID) cohesive zone model
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Seismic performance evaluation of a self-centering precast reinforced concrete frame structure 被引量:4
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作者 Mao Chenxi Wang Zhenying 《Earthquake Engineering and Engineering Vibration》 SCIE EI CSCD 2021年第4期943-968,共26页
The seismic performance of a five-story,four-bay,self-centering precast reinforced concrete frame(SC-RCF),which was redesigned using the direct displacement-based design method,was analytically investigated.The analyt... The seismic performance of a five-story,four-bay,self-centering precast reinforced concrete frame(SC-RCF),which was redesigned using the direct displacement-based design method,was analytically investigated.The analytical model of the overall structure was developed in OpenSees.The multi-spring contact element was adopted to simulate gap open-close behavior at connection interfaces.The limit states of external mild steel dampers and unbonded post-tensioning strands were considered.Static pushover analyses were performed up to the roof drift of 10%.The nonlinear dynamic responses under four groups of ground motions(with different fault distances and site conditions)at six hazard levels(from the service to the very rare earthquake(VRE))were compared.Incremental dynamic analyses were implemented to quantify the structural collapse risk.The results showed that the structural responses of SC-RCF were satisfactory under all levels of earthquakes.The collapse safety of the structure under earthquakes up to VRE1 was adequate,while the structure would collapse to a large extent under VRE2 and VRE3. 展开更多
关键词 self-centering system precast RC frame unbonded post-tensioning incremental dynamic analysis collapse fragility
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OPTIMIZING DESIGN OF MECHANICAL SELF-CENTERING DEVICE FOR SUSPENSION HEIGHT 被引量:2
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作者 CAO Min ZHANG Yongchao YU Fan 《Chinese Journal of Mechanical Engineering》 SCIE EI CAS CSCD 2008年第6期69-75,共7页
Firstly, in view of the respective defects of existing self-centering devices for vehicle suspension height, the design scheme of the proposed mechanical self-centering device for suspension height is described. Takin... Firstly, in view of the respective defects of existing self-centering devices for vehicle suspension height, the design scheme of the proposed mechanical self-centering device for suspension height is described. Taking the rear suspension of a certain light bus as a research example, the structures and parameters of the novel device are designed and ascertained. Then, the road excitation models, the performance evaluation indexes and the half-vehicle model are built, the simulation outputs of time and frequency domain are obtained with the road excitations of random and pulse by using MATLAB/Simulink software. So the main characteristics of the self-centering suspension are presented preliminarily. Finally, a multi-objective parameter design optimization model for the self-centering device is built by weighted sum approach, and optimal solution is obtained by adopting complex approach. The relevant choosing-type parameters for self-centering device components are deduced by using discrete variable optimal method, and the optimal results are verified and analyzed. So the performance potentials of the self-centering device are exerted fully in condition of ensuring overall suspension performances. 展开更多
关键词 Suspension height self-centering Vehicle height adjustment Optimizing design Multi-objective optimization
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Numerical simulation of the seismic behavior of self-centering steel beam-column connections with bottom flange friction devices 被引量:3
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作者 Guo Tong Song Lianglong Zhang Guodong 《Earthquake Engineering and Engineering Vibration》 SCIE EI CSCD 2011年第2期229-238,共10页
A new type of steel moment resisting frame with bottom flange friction devices (BFFDs) has been developed to provide self-centering capacity and energy dissipation, and to reduce permanent deformations under earthqu... A new type of steel moment resisting frame with bottom flange friction devices (BFFDs) has been developed to provide self-centering capacity and energy dissipation, and to reduce permanent deformations under earthquakes. This paper presents a numerical simulation of self-centering beam-column connections with BFFDs, in which the gap opening/closing at the beam-column interfaces is simulated by using pairs of zero-length elements with compression-only material properties, and the energy dissipation due to friction is simulated by using truss elements with specified hysteretic behavior. In particular, the effect of the friction bolt bearing against the slotted plate in the BFFDs was modeled, so that the increase in lateral force and the loss of friction force due to the bolt bearing could be taken into account. Parallel elastic-perfectly plastic gap (ElasticPPGap) materials in the Open System for Earthquake Engineering Simulation (OpenSees) were used with predefined gaps to specify the sequence that each bolt went into the bearing and the corresponding increase in bending stiffness. The MinMax material in OpenSees is used to specify the minimum and maximum values of strains of the ElasticPPGap materials. To consider the loss of friction force due to bok bearing, a number of parallel hysteretic materials were used, and the failure of these materials in sequence simulated the gradual loss of friction force. Analysis results obtained by using the proposed numerical model are discussed and compared with the test results under cyclic loadings and the seismic loading, respectively. 展开更多
关键词 numerical simulation post tensioned self-centering moment resisting steel frame bottom flange frictiondevice bolt bearing
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Floating Clamping Mechanism of PT Fuel Injector and Its Dynamic Characteristics Analysis 被引量:1
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作者 WANG Xinqing LIANG Sheng +2 位作者 XIA Tian WANG Dong QIAN Shuhua 《Chinese Journal of Mechanical Engineering》 SCIE EI CAS CSCD 2012年第3期550-556,共7页
PT fuel injector is one of the most important parts of modern diesel engine.To satisfy the requirements of the rapid and accurate test of PT fuel injector,the self-adaptive floating clamping mechanism was developed an... PT fuel injector is one of the most important parts of modern diesel engine.To satisfy the requirements of the rapid and accurate test of PT fuel injector,the self-adaptive floating clamping mechanism was developed and used in the relevant bench.Its dynamic characteristics directly influence the test efficiency and accuracy.However,due to its special structure and complex oil pressure signal,related documents for evaluating dynamic characteristics of this mechanism are lack and some dynamic characteristics of this mechanism can't be extracted and recognized effectively by traditional methods.Aiming at the problem above-mentioned,a new method based on Hilbert-Huang transform(HHT) is presented.Firstly,combining with the actual working process,the dynamic liquid pressure signal of the mechanism is acquired.By analyzing the pressure fluctuation during the whole working process in time domain,oil leakage and hydraulic shock in the clamping chamber are discovered.Secondly,owing to the nonlinearity and nonstationarity of pressure signal,empirical mode decomposition is used,and the signal is decomposed and reconstructed into forced vibration,free vibration and noise.By analyzing forced vibration in the time domain,machining error and installation error of cam are revealed.Finally,free vibration component is analyzed in time-frequency domain with HHT,the traits of free vibration in the time-frequency domain are revealed.Compared with traditional methods,Hilbert spectrum has higher time-frequency resolutions and higher credibility.The improved mechanism based on the above analyses can guarantee the test accuracy of injector injection.This new method based on the analyses of the pressure signal and combined with HHT can provide scientific basis for evaluation,design improvement of the mechanism,and give references for dynamic characteristics analysis of the hydraulic system in the interrelated fields. 展开更多
关键词 PT fuel injector floating clamping mechanism dynamic characteristics analysis Hilbert-Huang transform
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IMPROVE THE KINETIC PERFORMANCE OF THE PUMP CONTROLLED CLAMPING UNIT IN PLASTIC INJECTION MOLDING MACHINE WITH ADAPTIVE CONTROL STRATEGY 被引量:3
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作者 QUAN Long LIU Shiping 《Chinese Journal of Mechanical Engineering》 SCIE EI CAS CSCD 2006年第1期9-13,共5页
The kinetic characteristics of the clamping unit of plastic injection molding machine that is controlled by close loop with newly developed double speed variable pump unit are investigated. Considering the wide variat... The kinetic characteristics of the clamping unit of plastic injection molding machine that is controlled by close loop with newly developed double speed variable pump unit are investigated. Considering the wide variation of the cylinder equivalent mass caused by the transmission ratio of clamping unit and the severe instantaneous impact force acted on the cylinder during the mold closing and opening process, an adaptive control principle of parameter and structure is proposed to improve its kinetic performance. The adaptive correlation between the acceleration feedback gain and the variable mass is derived. The pressure differential feedback is introduced to improve the dynamic performance in the case of small inertia and heavy impact load. The adaptation of sum pressure to load is used to reduce the energy loss of the system. The research results are verified by the simulation and experiment, The investigation method and the conclusions are also suitable for the differential cylinder system controlled by the traditional servo pump unit. 展开更多
关键词 Adaptive control Pump controlled system clamping unit Plastic injection molding machine
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Seismic performance of a reinforced concrete building retrofitted with self-centering shape memory alloy braces 被引量:2
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作者 Massimiliano Ferraioli Antonio Concilio Carmine Molitierno 《Earthquake Engineering and Engineering Vibration》 SCIE EI CSCD 2022年第3期785-809,共25页
Self-centering earthquake-resistant structures have received increased attention due to their ability to reduce post-earthquake residual deformations and,thus,repair time and cost.This stimulated the development of re... Self-centering earthquake-resistant structures have received increased attention due to their ability to reduce post-earthquake residual deformations and,thus,repair time and cost.This stimulated the development of recentering shape memory alloy(SMA)dampers that use superelastic nitinol wires to dissipate energy and self-center the structure.However,there are still a few case studies applications on full-scale RC buildings in the literature.Moreover,general guidelines or even simplified approaches for the practical design of SMA damped braces are still lacking.This paper focuses on evaluating the effect of using self-centering shape memory alloy dampers for buckling-restrained braces applied for the seismic retrofit of a complex RC building structure.A design method originally proposed for elastoplastic dampers was implemented to size the SMA dampers to be placed on selected spans and stories of a building.The effectiveness of the design procedure was demonstrated by nonlinear time-history analyses under different sets of earthquake strong ground motions.The analysis results show that the recentering shape memory alloy bracing system is effective in limiting the maximum transient inter-story drifts and reducing the residual inter-story drifts after strong seismic events,due to its excellent recentering behavior together with its not negligible energy dissipation capacity. 展开更多
关键词 RC buildings seismic retrofit buckling-restrained braces shape memory alloys dampers self-centering
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MODELING, VALIDATION AND OPTIMAL DESIGN OF THE CLAMPING FORCE CONTROL VALVE USED IN CONTINUOUSLY VARIABLE TRANSMISSION 被引量:4
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作者 ZHOU Yunshan LIU Jin'gang +1 位作者 CAIYuanchun ZOU Naiwei 《Chinese Journal of Mechanical Engineering》 SCIE EI CAS CSCD 2008年第4期51-55,共5页
Associated dynamic performance of the clamping force control valve used in continuously variable transmission (CVT) is optimized. Firstly, the structure and working principle of the valve are analyzed, and then a dy... Associated dynamic performance of the clamping force control valve used in continuously variable transmission (CVT) is optimized. Firstly, the structure and working principle of the valve are analyzed, and then a dynamic model is set up by means of mechanism analysis. For the purpose of checking the validity of the modeling method, a prototype workpiece of the valve is manufactured for comparison test, and its simulation result follows the experimental result quite well. An associated performance index is founded considering the response time, overshoot and saving energy, and five structural parameters are selected to adjust for deriving the optimal associated performance index. The optimization problem is solved by the genetic algorithm (GA) with necessary constraints. Finally, the properties of the optimized valve are compared with those of the prototype workpiece, and the results prove that the dynamic performance indexes of the optimized valve are much better than those of the prototype workpiece. 展开更多
关键词 Dynamic modeling Optimal design Genetic algorithm clamping force control valve Continuously variable transmission (CVT)
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Liver injury after intermittent or continuous hepatic pedicle clamping and its protection by reduced glutathione 被引量:2
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《Hepatobiliary & Pancreatic Diseases International》 SCIE CAS 2004年第2期209-213,共5页
关键词 HEPATIC PEDICLE clamping HEPATIC ISCHEMIA/REPERFUSION injury reduced GLUTATHIONE PROTECTION
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Plastic Deformation Mechanism in Double-Roller Clamping Spinning of Flanged Thin-Walled Cylinder 被引量:2
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作者 Shu-Qin Fan Sheng-Dun Zhao Chao Chen 《Chinese Journal of Mechanical Engineering》 SCIE EI CAS CSCD 2018年第3期76-84,共9页
Double?roller clamping spinning(DRCS) is a new process for forming a thin?walled cylinder with a complex surface flange. The process requires a small spinning force,and can visibly improve forming quality and producti... Double?roller clamping spinning(DRCS) is a new process for forming a thin?walled cylinder with a complex surface flange. The process requires a small spinning force,and can visibly improve forming quality and production e ciency. However,the deformation mechanism of the process has not been completely understood. Therefore,both a finite element numerical simulation and experimental research on the DRCS process are carried out. The results show that both radial force and axial force dominate the forming process of DRCS. The deformation area elongates along the radial direction and bends along the axial direction under the action of the two forces. Both the outer edge and round corner of the flange show the tangential tensile stress and radial compressive stress. The middle region shows tensile tangential stress and radial stress,while the inner edge shows compressive tangential stress and radial stress. Tan?gential tensile strain causes a wall thickness reduction in the outer edge and middle regions of the flange. The large compressive thickness strain causes material accumulation and thus,an increase in the wall thickness of the round corner. Because of bending deformation,the round corner shows a large radial tensile strain in addition. The inner edge of the flange shows small radial compressive strain and tensile strain in thickness. Thus,the wall thickness on the inner edge of the flange continues to increase,although the increment is small. Furthermore,microstructure analysis and tensile test results show that the flanged thin?walled cylinder formed by DRCS has good mechanical properties. The results provide instructions for the application of the DRCS process. 展开更多
关键词 FLANGE Double?roller clamping spinning Plastic deformation CYLINDER
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