Search

The power bond graph of hydraulic system of power-slipway for combined machine tools was built on the basis of analysis on its hydraulic system and actual working cases. Dynamic model of hydraulic system of power-slipway was built. At the same time, making use of Simulink, dynamic simulation of hydraulic system of power-slipway was carried out. Influence law of primary technology parameters on dynamic characteristics of the hydraulic system of power-slipway was expounded. The simulation results will provide theory basis for performance analysis and optimal design of hydraulic system of power-slipway for combined machine tools.

In seasonal frozen regions, shallow landslide hazards in soil slopes usually happen. The type of failure surface is always on the freezing and thawing surface in the soil slope. So the direct influence factor of soil slope failure is the soil shear strength of the freezing and thawing (F-T) surface. The shear strength of the soil is determined by the two parameters of Cohesion c and Friction angle φ. In this study model experiment of F-T soil interface with different aggregate materials is designed by alternating the F-T cycle times, then the parameters c and the φ were obtained. Finally the deterioration modal of the two shear strength parameters of soil interface was put forward. The results demonstrated when the slope stability in the seasonal frozen regions was analyzed using shear strength reduction method, the two deterioration modals can provide the data reference for the analysis.

The machining quality of rolling bearing raceway has an important impact on bearing life. In this paper, the finishing experiment equipment of rolling bearing raceway is built and the mechanical and electrochemical mechanical experiments are conducted. The impact of clearance between cathode and workpiece, the rotation speed and the abrasive grain size on electrochemical mechanical machining quality is analyzed. The surface roughness decreases from Ra0.20μm to Ra0.04μm through electrochemical mechanical machining. The surface morphology of workpiece after finishing is observed. Contrast with the surface morphology after conventional mechanical polishing, the surface after electrochemical mechanical finishing is more suitable to the bearing raceway.

This article reports a sub-domain method to analyze the dynamic interaction of soil-high-rise building group considering sit effect, which is the extension of the domain reduction method proposed by Bielak and his coworkers in the framework of the finite-element method, originally for building–soil–foundation interaction problems. The whole domain with high-rise building group is divided into two interrelated sub-domains, the external domain and the internal one. And the method contains two steps. In addition, the effect of the external domain to the internal domain is expressed by the equivalent forces which are put on the nodes of the interface between the two sub-domains in the second step. The formation of the equivalent force is attained according to the equation of motion. In the first step the free-field ground motion is calculated under the bedrock wave excitation, and all the nodal displacements are stored. Then the equivalent forces are calculated according the data in the first step, using the formulation of the equivalent force. In the second step a finite element analysis model of the sub-domain containing the internal domain and the high-rise building group is established, and the equivalent forces are put on the nodes of the interface. Later the seismic response of soil-high-rise building group can be calculated.

Composite steel plate shear wall (CSPSW), as a new lateral force resisting structure composed of steel plate and concrete slab, is introduced. CSPSWs can fully display the superiority of the steel plate and concrete. Ductility and energy dissipation capacity of the walls are increased and seismic behavior is improved. Recent seismic research around the word of two kinds of CSPSWs, namely, CSPSW with signal steel plate and CSPSW with double steel plates, is presented and discussed comprehensively. Some existing problems in current research of the walls are also reviewed in this paper.

In a performing art center project, the roof system uses steel trusses with large-span, which challenges the installation of trusses in construction. Two SCC400 hydraulic crawler cranes are arranged to lift roof trusses. Since it is impossible to sustain the huge cranes for structural slabs, an independent steel trestle will be constructed along the moving path of cranes. The steel trestle is a special frame system with three kinds of levels. Constrained by constructed basement structures, steel trestle has a complex shape and some long span members. It requires some members high capacity and stability. To investigate its mechanics properties, especially the whole stability, a set of analysis, including static and elastic buckling analysis, are carried out on this steel trestle by use of ANSYS software. According to the working conditions of crawler cranes, the loads caused by walking of cranes and hoisting trusses are considered. On the basis of the static analysis, the dangerous loading areas are determined to conduct eigenvalue buckling analysis. The results show that the loads in different positions have less impact on the force and deformation of the entire structure. The buckling characteristic value of the first four modes in both load conditions is larger than 1, which indicates that the system has enough stability.

This paper introduces the structure of the resin bonded abrasive wire saw manufacture equipment. The equipment can complete the process of the wire saw production, including uncoiling wire, cleaning wire, binder coating, Pre-curving and coiling wire. Wire saw are manufactured successfully by this equipment in the manufacture experiment. The quality of the wire saw was examined by SEM. The average slicing ability of the wire saw is 205 mm2 per meter in the experiment of KDP crystal slicing.

Results of an experimental investigation to study the structural behavior of new GSZ panels are reported. Three half-scale new GSZ panels with variable reinforcement ratio were cast and tested under vertical loading and low cycle reversed horizontal loading. The failure process, strains in vertical steel bars and surface–concrete, load–displacement curve under increasing load were recorded and analyzed. Result obtained showed that the entirety performance of new GSZ panel is excellent. And the reinforcement ratio has a great influence on the lateral stiffness of the panel.

Elastic tube bundles are universally used in heat transfer enhancement via the flow-induced vibration in heat exchangers, and the study of the tube vibration characteristic is essential. The natural vibration of multiple conical spiral tube bundles was discussed in this paper based on numerical simulation. The substructures of ten conical spiral tubes, the inlet and the outlet branch were set up individually. Then the mass matrix and the stiffness matrix of these substructures were calculated. The general matrices were obtained and the vibration equation of the overall structure was founded. The results show that the natural frequencies of the multiple conical spiral tube bundles are smaller than the traditional planar elastic tube bundles and each natural vibration mode has a frequency band, which contains several natural frequencies.

The mechanism of melt treatment improving the glass forming ability (GFA) and thermal stability of the Al84.5Ni5.5Y10 (in atomic percentage) alloy was studied. An yttrium-rich metastable high-melting-temperature-phase is found to be responsible for the deterioration of GFA because it induces the heterogeneous nucleation of the crystals in the solidification process. It can be eliminated through melt treatment as adopted in this paper, resulting in stabilizing the thermal stability of the undercooled melt and enhancing the GFA of the investigated alloy with higher thermal stability for the resultant amorphous phase.

The negative high-voltage power supply of Electron Cyclotron Resonance Heating (ECRH) is a nonlinear system with serve sensitivity and it is not well for traditional controller to meet restrict demand on stability and quick response. Based on the concept of credit a novel CMAC is designed to accelerate the convergence of traditional CMAC and also is used as an intelligent controller for the power of ECRH based on the idea on direct inverse control. Experiment results show that ICA-CMAC can control the power of ECRH well with shorter settling time and less CPU consumption thus the validity of ICA-CMAC is determined.

In this paper, a novel improved Credit Assigned CMAC (ICA-CMAC) is designed based on the concept of credit to enhance the performance of the traditional CMAC. Then ICA-CMAC is used to predict the human hepatic clearance according to in-vitro data of drugs. The experiment results show that the prediction by ICA-CMAC is faster and more accurate and can be thought as a new and effective way for drug metabolism prediction.

Soil slope is one of the main parts of the road engineering. The stability of the slope is an essential prerequisite to ensure the safe operation of road transport. In seasonal frozen regions, shallow landslide hazards in soil slopes usually happen, which pose a serious threat to road safety operations. During the melting process, there forms stagnant water lubrication between the melting soil and freezing soil interface, which constitutes the weak interface of landslide hazard. Special methods to form the freezing – thawing (F-T) surface is designed, and takes consider the interface strength as the foundation of experimental tests, then opening to research the soil slope stability. Safety factor modification of the soil slope is presented. The conclusions of this paper present well theoretical and applied value to the regional slope failure analysis.

Hollow glass fiber with full of repair agent is embedded in concrete to repair components, and one - third point loading experiment is carried out to test the mechanical properties of it. Based on the strength analysis of specimens before and after self – healing, the self – healing effect of concrete is evaluated. By simulating the closed heal agent flowing and penetrating into the concrete crack surface under the capillary tension, the influence of crack width to the healing effect is analyzed.

Grind-hardening is a new integrated machining technology which utilizes grinding heat to quench the non-quenched steel directly. In this paper, the technology is applied in the process of rack form grinding. A comprehensive numerical model is developed to simulate the temperature distributions of the rack under the dry grind-hardening conditions with finite element method(FEM). The temperature dependency of the thermal properties, the triangular heat distribution of the heat flux, latent heat and the air convection are taken into account. The simulated hardness penetration depth(HPD) is deduced from the local temperature distribution, time history of workpiece according to martensitic phase transformation theory. This provides a reliable method for the proper selection of process parameters in order to produce enough heat at the contact zone, enabling the treatment of the rack.

The purpose of this paper is to modify the resin binder for developing resin-bonded diamond wire saw. The optimization of components with different ratios in the resin binder was investigated using orthogonal design experiments. Besides, the resin-bonded diamond wire saw was developed using the piano wire (the diameter is 0.2mm), the modified resin and the diamond abrasive (the diameter is 20~30μm). Good surface quality and slicing performance were obtained when slicing silicon crystal using the resin-bonded diamond wire saw we made in the experiments.

The heat partitioning to workpiece is an important parameter, which affects the grind-hardening technology. In this paper, the heat sources positions, which are around the grain, are analyzed. Ignoring the heat source produced in chip-grain interface, the heat partition model is established based on heat source position produced in grain-workpiece interface and the chip-workpiece interface. The heat partition is validated by using of finite element method and the experimental method. The results indicate the heat partition model can be used in grind-hardening temperature calculation.

The experiments are performed to study the hardness layer depth at work piece different surface zone in grinding. The result is that hardness layer depth is various at work piece different surface zone. The hardness layer depth is thinner at cutting-in grinding zone, deeper at middle grinding zone and deepest at cutting-off grinding zone. In order to analyze the cause of hardness depth variation, the grinding temperature field is simulated by means of finite element method. From the temperature field and heat flux simulation, the cause of the hardness depth variation is that the grinding heat flux is variable at different grinding zone along the work piece surface in grind-hardening. At cutting-in zone, most of grinding heat flows into the front-below work piece part inverse to table speed, the depth that temperature of surface layer higher than austenite temperature is thin and there is slim martensite transformation layer. At middle zone, the temperature of surface layer is higher than austenite temperature because of grinding heat accumulated in the surface layer, and martensite transformation takes place after cooling. At cutting-off zone, most of grinding heat flows into the below work piece part because of work piece boundary, and hardness depth is deeper than that at middle zone.

The grinding force was one of the most important parameters, almost related with all the parameters in grinding. In this paper, the grinding force model was established by a new method. The abrasive grains were analyzed using the statistical probability method. The abrasive grains were divided into two types, one was the cutting abrasive grain, and the other was contacting abrasive grain. The force analysis of a single abrasive grain was done. The grinding force model was established on the basis of the statistical probability method and the force analysis of a single abrasive grain. Theoretical analysis was verified by the experiment. The results indicated, the experimental results agree well with the theoretical prediction. The model can accurately predict the grinding force.