最新刊期
卷 46 ， 期 4 ， 2014
- 摘要：Abstract:In order to describe the velocity distribution of plug flow and provide the basis for plug design，stepped plug and gradually contracted plug were measured by LDV.The results showed that the time average velocity becomes uniform after 0.133 times tunnel diameter from plug inlet.The time average velocity after expansion becomes uniform after 3 times tunnel diameter from plug outlet.The reattachment points after outlet of the plug are 1~2 times diameter of the tunnel from plug outlet.In general,the radial time average velocity beyond circulation area is 10 percent of that of axial.The fluctuation velocity is 10~30 percent of time average velocity and the maximum of it lies in the area where the grad of velocity is relatively high.As far as the same section is concerned,the fluctuation velocity at axis is relatively smaller than other point.From the point of the velocity distribution,plug length should be greater than 0.133 times the pipe diameter,and the distance between plugs should be greater than 3 times the pipe diameter.关键词：plugdissipater;flowfield;LDV
- 2451
- |
- 0
- |
- 0
发布时间：2023-11-14 - 摘要：Abstract:The failure criteria and failure models of slopes in the numerical calculations of slope stability were discussed extensively by using theoretical analysis and two typical examples.Qualitative mechanical analyses showed that, if subjective factor was avoid, the frequently-used three types of criterion could reflect concordantly the slope failures under strict convergence criteria,which was verified by the numerical example 1. Failure modes of the slope were determined by the yield criterion of rock and soil mass. In order to make the numerical analyses satisfied with the engineering practice,the tensile modification should be carried out in the yield criterion based on shear failure like Mohr-Coulomb yield criterion. On the basis of shear and tensile composite failure of rock and earth mass,a numerical strength reduction process was set up, and this process was proved more reasonable and justified by the calculation example 2.关键词：slopestability;numericalcalculations;failurecriteria;yieldcriterion
- 2380
- |
- 0
- |
- 4
发布时间：2023-11-14 - 摘要：Abstract:One of the key technical problems of flood discharge tunnel with spiral flow shaft is gas burst being prone to occur at the outlet,as the discharging tunnel is difficult exhaust under the condition of high tail water level.For this regard,numerical simulation was conducted and combined with a tunnel project to study a novel type of vortex shaft in a flood discharge tunnel with submerged outlet.Flow pattern features,pressure distribution and other characteristics of this flow were obtained and they agreed well with the experimental results.The conversion mechanism of strong aerated turbulent flow to pressure flow and its influence on structure were discussed. Research showed that,the horizontal section can be divided into a mixing and energy dissipation area which is the main disinfection energy,an air bubble escaping area,an air discharge zone,and a smooth flow zone. In the condition of submerged outlet,the air escapes successfully, the flow pattern converts smoothly along the tunnel, and the bottom pressure is distributed reasonably. This research can be a reference for similar projects.关键词：vortexshaftwithsubmergedoutlet;flowpatternconversion;turbulencemodel;hydrauliccharacteristic
- 2500
- |
- 2
- |
- 9
发布时间：2023-11-14 - 摘要：Abstract:Scheduling rules and operation processes of floodgate were fully considered,and the model of flood control operation was established based on multi step progressive optimal algorithm (MSPOA).Floodgate digital representative combination strategy was proposed and dichotomy was introduced to distribute the discharged flow of reservoir to floodgates.The optimal results of two typical floods showed that computing time of MSPOA decreases 43.2% and 64.0% compared with POA,respectively.MSPOA has a faster convergence speed,and could effectively overcome the local optimal defects.The flood control operation based on MSPOA and combined strategy have good practicability and maneuverability.关键词：floodgate;floodcontroloperation;reservoir;YalongRiver
- 2360
- |
- 0
- |
- 3
发布时间：2023-11-14 - 摘要：Abstract:In order to improve the accuracy of river hydraulic model, ensemble Kalman filtering method based on the concept of ensemble was used for real-time updating model states.The key of ensemble Kalman filter lied in the set of initial state ensemble,so that Box Muller method was adopted to generate a set of normally distributed random ensemble.A simulation of a river network composed of 14 channels was used to systematically analyze the data assimilation effect about size and standard deviation of ensemble,gaining preliminary conclusions which were applied to a real case.The results showed that the ensemble Kalman filtering algorithm with easy and wide-range application is able to effectively carry out data assimilation of river nonlinear dynamic system, and ensemble scale ranging form 50 to 100 along with standard deviation ranging from 0.001 to 0.005 m is recommended when setting the initial stage state ensemble.关键词：rivernetwork;dataassimilation;ensembleKalmanfilteringalgorithm
- 3182
- |
- 4
- |
- 3
发布时间：2023-11-14 - 摘要：Abstract:A new classification method,which considers the depth of limit equilibrium zone in the surrounding rock as its indicator,was put forward.This method takes the impact of mining and coal rock mechanical properties and the degree of weathering of seam roof into consideration to get the final plastic failure zone radius,which is revised in accordance with connecting situation between the plastic damage zone and the weathered zone of seam roof,as the core of this method.The application in 11912 working face of Gequan mine,which is complex and severely weathered in some roof,showed that this classification method has good supporting effect.关键词：seamroof;weathering;plasticzone;support;classification
- 1925
- |
- 0
- |
- 0
发布时间：2023-11-14 - 摘要：Abstract:With the aid of MTS815,large scale laser profilometer and SEM testing system,indirect tensile tests,fractography and meso fracture mechanism analysis were carried out on layered marbles taken from transportation tunnel of JinpinⅡ hydropower station.Experimental results indicated that the included angle between tensile stress direction and bedding plane significantly influenced tensile strength and fracture mechanism of marble.The average tensile strength is approximately 6.32 MPa when the direction of tensile stress is parallel to the bedding plane.And the fractography is rough and surface fractal dimension is about 2.14~2.17 in this case.However,the average tensile strength is about 6.32 MPa when the direction of tensile stress is perpendicular to the bedding plane.And the fractography is more smooth and surface fractal dimension is only 2.07~2.10 in this case, which indicates clearly that there is a good corresponding relationship between tensile mechanical properties and fractography in layered marble. For the same kind of rock,the rougher the fracture surface presents,the greater its fractal dimension will be.And it will correspond to a higher tensile strength,vise versa.The meso-fracture mechanism was also studied through SEM. When the tensile stress is parallel to the bedding plane,the intergranular fracture occurs,but the transgranular fracture is relatively less. When the tensile stress is perpendicular to bedding plane,the facture mode changes to mixed fracture mode,namely,coupled intergranular fracture and transgranular fracture. Different micro/meso-fracture modes are the fundamental reasons which induce different fracture morphology and tensile properties in layered marble.关键词：rockmechanics;indirecttensiletest;fracturemorphology;fractaldimension;fracturemode
- 2044
- |
- 2
- |
- 7
发布时间：2023-11-14 - 摘要：Abstract:In order to investigate the shear behavior of composite beam with web opening under negative moment,simply supported composite beam under concentrated load were tested.The test results showed that the stiffness and ultimate capacity decreases significantly after web opening and the plane hypothesis is not satisfied any more.The failure mode is shear fracture in concrete slab near the opening area,and some stud connectors in opening area are pulled off.The ultimate load bearing capacity and deformation capacity can be effectively enhanced by increasing the thickness and reinforcement ratio of a concrete slab.This research provides an experimental basis for the EFA and the application of composite beams with web openings under negative moment.关键词：composite beam;web opening;negative moment;shear behavior;experimental study
- 2163
- |
- 7
- |
- 2
发布时间：2023-11-14 - 摘要：Abstract:In order to study the effect of rubber on the mechanical properties of rubberized self-compacting concrete (RSCC) and establish the corresponding constitutive prediction model,compressive stress-strain experiment for RSCC was carried out，and the experimental results showed that with the increase of rubber content，the compressive strength of RSCC reduces，the deformation ability enhances and the toughness increases.Through considering the relation between model parameters and rubber content，a statistical damage constitutive relation of RSCC whose change factor is rubber content was established according to the assumption that the micro-unit strength of RSCC is of random distribution and Mises strength criterion，the distribution model of micro-unit strength of RSCC is of logarithmic normal distribution，whose fitting effect is very ideal，the correlation coefficients of fitting curves and test curves increase with the increase of rubber content，whose maximum value is 0.989 1.This model has a few parameters and is easy in calculation，which can effectively reflect the transformation characteristics of toughness and brittleness of RSCC in different rubber contents. Finally，the damage evolution process of RSCC was studied.With the increase of strain，the damage evolution curves of RSCC are in a shape of S and monotonically increase，whose final values tend to 1，and the increase of rubber content delays the development of initial damage of RSCC；the development rate of damage first increases and then decreases with increase of strain，which reaches the maximum near the peak strain，and the change of rubber content has no influence on the maximum of the development rate of damage.关键词：rubberizedself-compactingconcrete;content;micro-unitstrength;statisticaldamageconstitutiverelation;parameter
- 2266
- |
- 0
- |
- 3
发布时间：2023-11-14 - 摘要：Abstract:In order to improve the flexibility of trust computing in the model,the trusted domain was divided into three decision domains.Problem of adaptability was solved by introducing time adjustment into the model.Stability function tackled weight distribution problem during calculating total value.Consideration of interaction history and the distribution of trust while making evaluation strategy saved computing resources.Moreover,investigation table about direct recommendation entity was put forward to identify and restrict false recommendation problems effectively.Simulation results showed that this model has a better accuracy,convergence and adaptability in dealing with complex malicious attacks and fraud in the model.关键词：distributednetwork;trustevaluation;trustdomain;weightdistribution
- 2172
- |
- 6
- |
- 0
发布时间：2023-11-14 - 摘要：Abstract:In order to optimize the index reduction technology of sparse differential algebraic equations (DAEs) from multi-domain unified modeling software,a heuristic algorithm for block fast index reduction method(BFIRM) was proposed. The main principle of BFIRM is to do block triangularization of DAEs’signature matrix,then to use Pryce method with parameters to process diagonal sub-square-matrix in block triangulated signature matrix from top to bottom in sequence.A large number of numerical experiment results showed that BFIRM can solve the canonical offsets vectors of sparse DAEs efficiently. And the reduction efficiency positively correlates with the number of the diagonal blocks.Moreover,to take CNC punch machine tool as an example,its DAEs was reduced by the BFIRM.This method was verified effectively in reducing the index of large-scale DAEs with high index and easily got DAEs’structural information, such as canonical offsets vectors.关键词：multi-domainunifiedmodeling;differentialalgebraicequations;indexreduction;Prycemethod;blockfastindexreductionmethod;CNCpunchingmachinetool
- 2211
- |
- 0
- |
- 1
发布时间：2023-11-14 - 摘要：Abstract:A new forensics technology was proposed in order to improve the accuracy and recall rate vague of evidence tampering retouching techniques. By detecting the origin image’s naturally strong edges on attribute reduction rules built by energy ratio and information entropy, using edge preserving smoothing filter structure to enhanced fuzzy region and detect the image’s edges, designing artificial fuzzy membership function to compute every pixel’s fuzzy membership and use it to detect the origin image’s fuzzy edges, merging all the images and processing them through artificial collection of fuzzy membership, the accurately and clearly artificial fuzzy edges were obtained. Experimental results showed that the new algorithm gets a higher precision and recall rate, distinguishes artificial and natural blur better, and detects tampered region better.关键词：fuzzyretouching;attributereductionrules;naturallystrongedge;edgesmoothingfilterstructure;artificialfuzzymembershi
- 2373
- |
- 16
- |
- 1
发布时间：2023-11-14 - 摘要：Abstract:The video block-matching and 3-D filtering (VBM3D) algorithm was improved, which had block effect and low-efficiency. A continuous derivative threshold method was introduced during the shrinkage of the coefficient in transform domain, replacing the hard threshold method. A fast method based on the integral images was used to calculate the distance between image blocks in intra frames matching. An improved searching method of predictive-search block-matching for inter frames matching was presented. The computation was reduced and the efficiency of the algorithm was improved on the premise of finding similar blocks. The experimental results and the theoretical analysis demonstrated that the improved method achieved excellent denoising performance. The result of block effect in the original VBM3D algorithm was improved and the computation complexity of improved algorithm was reduced greatly.关键词：videodenoising;VBM3D;three-dimensionaltransform;continuousderivativethreshold;block-matching
- 3130
- |
- 0
- |
- 2
发布时间：2023-11-14 - 摘要：Abstract:The performance and stability related issues in WEB applications were studied and the results showed that some application layer protocol (such as HTTP, SSDP, etc.) structures have attributes like limited field, fixed number of field name, obvious position for field values and unstructured. A general application protocol parsing acceleration algorithm was proposed to prompt signaling handle efficiency. The key idea is the protocol field extended tree. The proposed algorithm was demonstrated and analyzed, and its time complexity only grows with not protocol content length but the sum of each field length in protocol format. The comparion with the algorithms used for existed protocol parsing methods in well-known WEB applications proved this algorithm outperformance 16.5% in throughput than compared methods under the same test conditions. Besides, the proposed algorithm could be applied to both ASCII and binary application protocols with good scalability.关键词：protocolcontentparsing;protocolfieldtree;protocolfieldseparator;stringmatching
- 2598
- |
- 0
- |
- 0
发布时间：2023-11-14 - 摘要：Abstract:To ensure the effectiveness of network policies of virtual machines in infrastructure as a service (IaaS ) environments which adopted the virtual ethernet bridge ( VEB ) model,a policy dynamic loading mechanism for virtual network interface (VIF) of virtual machine at runtime was studied.Through decoupling the network policy information from virtual machine native configure file,analyzing the factors of impacting the effectiveness of VIF’s policy and defining the essential factors of loading VIF’s policy,a mechanism was proposed to load the policy to right place at the appropriate time point to ensure the effectiveness of network policies in total life cycle of virtual machine.The results showed that the VIF’s policy could be loaded completely in milliseconds and the policy lacking period was eliminated,and based on the independent character of network policies,the policies on-demand extension and dynamic change for virtual machine at runtime were supported.关键词：cloud computing;dynamic loads;IaaS;life cycle;network policy
- 2224
- |
- 10
- |
- 1
发布时间：2023-11-14 - 摘要：Abstract:To study the information processing method in QPSO（quantum-behaved particle swarm optimization） algorithm,random factors in the potential well center formula of QPSO was analyzed,the bivariate correlation factors concept was proposed,and internal relations between particles’own experience information (pbest) and group sharing information(gbest) using Normal Copula functions was established.Then,the binary correlations QPSO algorithm (BC-QPSO) was proposed,and the relations between the bivariate correlation factors and population diversity were studied through simulations. Simulation results of the six test functions showed that BC-QPSO algorithm outperfoms the standard QPSO algorithm in terms of optimization results by selecting the appropriate values of correlation coefficient.关键词：particleswarmoptimization;quantumpotentialwell;populationdiversity;convergence
- 1941
- |
- 0
- |
- 2
发布时间：2023-11-14 - 摘要：Abstract:In light of time lag when using degree of saturation to judge traffic congestion in the intersection,the concept of critical saturation vehicle queuing length was proposed,the ratio of the vehicle queuing length of phase start time and critical saturation vehicle queuing length was defined as vehicle queuing congestion rate,and vehicle queuing congestion rate was used to judge the traffic congestion in the crossroads, developing a bus signal priority strategy for bus transit.Vissim software was used to simulate the bus signal priority strategy and testify its feasibility.The simulation results showed that in comparison with non-priority strategy,the implementation of bus signal priority strategy can remarkably decrease the average vehicle delay and average person delay for priority phase, and the average person delay for the whole phase cycle,only slightly increase the average vehicle delay and average person delay for non-priority phase,and rarely change the average vehicle delay for the whole phase cycle,which shows that it is feasible to use vehicle queuing congestion rate to judge the traffic congestion of all direction in the crossroads and to implement bus signal priority strategy in the case of traffic congestion.关键词：bussignalpriority;saturationflowrateinvehicles;vehiclequeuelength;trafficcongestionrate;averagevehicledelay;averagepersondelay
- 2268
- |
- 20
- |
- 2
发布时间：2023-11-14 - 摘要：Abstract:A PARAFAC-based channel estimation method was proposed for two-hop amplify-and-forward (AF) multiple-input multiple-output (MIMO) relay systems. Through constructing PARAFAC model to the received signal matrices,full channel state information (CSI) involved in the communication can be estimated at the destination node by using the proposed optimal complex value alternating least-squares (CALS) algorithm.Comparison with existing approaches showed that the proposed method requires less number of training data blocks and has higher channel estimation accuracy.Simulation results demonstrated the effectiveness of the proposed channel estimation method.关键词：multiple-inputmultiple-output;relay;parallelfactor;channelestimation
- 2191
- |
- 0
- |
- 0
发布时间：2023-11-14 - 摘要：Abstract:In order to improve the topology fault-tolerance and resource utilization of multicast routing in wireless Mesh network, the fault-tolerant deficiency of a single multicast tree was described, the optimization model was established, and then the construction method of disjoint multicast tree was proposed based on augmentation disjoint paths. In this method, the wireless link interference was used as the link weights, by which node disjoint paths between the source node and the destination nodes and among the destinations nodes were calculated. Meanwhile, the disjoint among multicast trees was maintained by calculating the augmentation disjoint paths. By simulations and comparative analysis, the success ratio of the proposed method ascended 47.13% for solving the disjoint multicast trees, and the network performance of average throughput and delay also ascended 4.91% and 5.16%, respectively, which demonstrated that the proposed method is correct and valid.关键词：wirelessMeshnetwork;disjointmulticasttrees;topologyfault-tolerance;augmentationdisjointpath
- 2488
- |
- 4
- |
- 0
发布时间：2023-11-14 - 摘要：Abstract:To analyze the printfingers of HP TiO2 memristor model and compare the differences between the printfingers of the basic model and nonlinear window function models, the features of several typical HP TiO2 memristor nonlinear window function models were summarized and a unified model of HP TiO2 memristor was proposed. The printfinger analysis of HP TiO2 memristor basic model was further developed and the printfinger comparisons of several nonlinear window function models were then performed. The results demonstrated that all HP TiO2 memristor models can exhibit hysteresis loops pinched at the origin for any memristor initial state and any amplitude and frequency of the sinusoidal current stimulus. The printfingers of different nonlinear window function models are effected by the corresponding nonlinear drifts, which result in that the generated output voltages and memristances have different transient transition processes, and the effects of the nonlinear drifts become more serious with the increasing memristor initial state values, causing the performances failure of a part of HP TiO2 memristor models.关键词：memristormodel;windowfunction;printfinger;initialstate
- 1974
- |
- 0
- |
- 0
发布时间：2023-11-14 - 摘要：Abstract:In the initial period of power system restoration, in order to study the effect of the capacity and the sequence of loads that should be picked up to the restoration, fluctuation of load caused by the actual picked up load capacity and the important degree of load as well as numbers of switches between loads and black-start unit were considered, and the methods of differences and projections were used to order loads. Based on the results, a mathematical model was developed.A integrated optimal and feasible restoration program was obtained in the initial period of power system restoration. The effectiveness and practicality of the method were demonstrated by computer simulation performed on an actual restoration system in Sichuan Province in China.关键词：initial period of power system restoration;load restoration;load fluctuation;frequency index of load fluctuation;optimization
- 2139
- |
- 0
- |
- 0
发布时间：2023-11-14 - 摘要：Abstract:In order to reduce steady state errors of active and reactive powers in PWM converter and harmonic content of the AC side output currents, the power changing models of dead-beat predictive direct power control system of PWM converter were put forward. The voltage vector sequence method based on angular location of the converter AC side voltage was proposed. As angular deviation of the proposed method and the traditional ones in division sector, the same tendency of active or reactive powers change rate via selected three voltage vectors in even sectors was avoided and the phenomena of unreasonable duration time of auxiliary vector was removed. The proposed dead-beat predictive direct power control method has many advantages of rapid power adjustment, decreasing steady state errors of powers, reducing harmonic content of currents, fixing switching frequency, no coordinate transformation and space vector modulation, et al.关键词：pulse width modulation;switching frequency;power control;PWM converter;voltage vector sequence
- 2181
- |
- 0
- |
- 0
发布时间：2023-11-14 - 摘要：Abstract:Gradations of recycled coarse and fine aggregate (RCA and RFA) were modified, and then used to cast 288 recycled concrete (RC) cube specimens. The influence of gradation modification on cube compressive strength variability of RC and the related mechanism were studied. Results showed that the gradation curve of RCA and RFA was not fine enough according to the present codes,the gradation modification was a way to optimize the gradation curve of RCA and RFA, and the respective bulk density was increased and the crushing index was reduced.The cube compressive strength of RC decreased with the increase of the RCA replacement ratio in general, whereas the strength variability appeared when the RCA replacement ratio equaled 50%.The compressive strength showed normal distribution with the standard deviation ranged from 1.0 to 3.0 MPa.But the variability rose up with the standard deviation less than 3.0 MPa when the RCA replacement ratio was 50%.The standard deviation of RC compressive strength obviously decreased after the gradation modification,which meant that the scatter of the compressive strength was controlled.Besides,the variability of RC increased with the RFA replacement ratio increased from 0 to 30%.关键词：recycledaggregate;gradationmodification;recycledconcrete;compressivestrength;variability
- 1960
- |
- 0
- |
- 21
发布时间：2023-11-14 - 摘要：Abstract:For the development and utilization of collagen,the influences of N-hydroxysuccinimide activated adipic acid derivative (NHS-AA) on the steady flow,dynamic viscoelasticity,thixotropy and creep of collagen solution were studied by the rheometer.The results showed that the solutions cross-linked by different doses of NHS-AA were all pseudoplastic.The viscosity of collagen solutions increased with the increase of the dose of NHS-AA. The elastic modulus of collagen solutions increased dramatically due to the addition of NHS-AA and that indicated that NHS-AA reinforced the elasticity of collagen solution.The thixotropy of collagen solution became strong after adding NHS-AA,suggesting that the recovery of network structure broken by shear stress became slow.Adding NHS-AA resulted in the decrease of the compliance of collagen solution，reflecting that the cross-linked collagen solution was more difficult to transform with shear stress.All the experiments results indicated that the rheological properties of collagen solution could be adjusted by NHS-AA.关键词：collagen;N-hydroxysuccinimide activated adipic acid derivative;steady flow;dynamic viscoelasticity;thixotropy;creep
- 2216
- |
- 0
- |
- 0
发布时间：2023-11-14 - 摘要：Abstract:A coupling model for dynamic and tribological performances for a piston was established, in which the effects of surface roughness, bulk elastic deformation and contact between the piston skirt and cylinder were considered. Based on this model, the cylinder vibration was solved with the Broyden algorithm, whose effects on the secondary motion and lubrication performances of the piston were analyzed. Numerical results showed that the maximum vibration displacement and acceleration of the cylinder occur in the power stroke. With the increase of the rotational speed of the engine, the maximum cylinder displacement increases. If the cylinder vibration is considered, the secondary velocities of the piston, the amplitude of the local film pressure and minimum film thickness fluctuate and the averaged friction power loss increases, compared with the corresponding values without the cylinder vibration.关键词：secondarymotion;iubricationperformances;cylindervibration;pistonskirt;Broydenalgorithm
- 2075
- |
- 4
- |
- 0
发布时间：2023-11-14 - 摘要：Abstract:The conceptual design of complex product can be considered as a process which involves intensive iteration,complex reasoning and mutual cooperation among the design groups of various disciplinary areas. In order to provide support for computer-aided design,the conceptual design model of product design with multidisciplinary collaboration was first established,the collaborative mechanism of function,behavior and structure was studied, and the reciprocating mapping of vertical collaborative was analyzed.Then,based on the Muti-Agent,the implementation framwork with multidisciplinary collaboration in conceptual design was built and the solving and reasoning mechanism between Agents with multidisciplinary collaboration were also established.Finally, the conceptual design process of a certain type of wire printer was used to illustrate the application of the proposed method and demonstrate its innovation.关键词：Muti-Agent;complex product;multidisciplinary collaborative;conceptual design
- 2260
- |
- 4
- |
- 0
发布时间：2023-11-14 - 摘要：Abstract:Mechanical joint often has a significant effect on the dynamical behavior of high-speed horizontal machining center.Identifying the dynamic parameters of the joints correctly is a prerequisite to establish its precise dynamic model.The method based on frequency response function (FRF) to identify the characteristic parameters of bolted joints and make some researches on the equivalent way was proposed by combining theoretical derivation with experimental research,which defined identification formula and sensitivity,and the experimental data was selected by sensitivity which could extract the favorable data and suppress the unfavorable data. On this basis,the inconsistent equation containing identification formula was established,and the equivalent dynamic parameters were obtained through solving the inconsistent equation by means of the least square sense.In the end,this method was applied to one experiment based on LMS system,and the result showed that it significantly improved the identification and equivalence precision.关键词：FRF;boltedjoints;normalstiffness;identification
- 1888
- |
- 2
- |
- 3
发布时间：2023-11-14 - 摘要：Abstract:The thermal and mechanical behaviors of running angular contact ball bearings(ACBB) are highly coupled. They are connected by a temperature induced force which is so-called thermal preload. An approach to analyze ACBB thermo-mechanical coupling behaviors was proposed.An integrated ACBB thermo-mechanical model was created based on multi-software collaborative computing platform. Effects of comprehensive thermal boundary conditions like joints thermal contact resistance, oil-air lubrication and the bearing surroundings convection on the ACBB thermal behaviors were investigated by using this integrated model. Temperature tests were performed on the bearing experimentation platform.The analytical model was validated by the virtue of temperature inspecting instrument through the temperature-measuring-hole that is fabricated on the bearing housing.Variation principles of ACBB thermal preloads under the different rotational velocities and initial preloads were studied, and effects of thermal preloads on the ACBB operational stiffness were analyzed.关键词：angularcontactballbearing(ACBB);integratedthermo-mechanicalmodel;thermalcontactresistance;thermalpreload;operationalstiffness
- 2562
- |
- 2
- |
- 1
发布时间：2023-11-14
- Technical support is provided by Beijing Founder electronics co., LTD 京ICP备09064830号-19
京公网安备11010802024621 - It is recommended to read the content of this site in Chrome&IE9+. Please switch to extreme mode in browser 360.
- Cookies We use cookies to help provide and enhance our service and tailor content. By continuing, you agree to the use of cookies.
0