Advanced Materials Research Vols. 148-149

Abstract: The methods and devices which can be used to determine the wettability and zeta potential of filter medium were developed according to the principles of capillary rise and streaming potential respectively. Lipophilic Hydrophilic Ratio (LHR) was defined based on Washburn equation. LHR values and zeta potentials of some conmen filter media were measured respectively, and the oil removal efficiencies of these filter media were also tested. The result shows that the effect of wettability on oil removal efficiency is much greater than that of zeta potential in conmen condition. The oil removal efficiency mainly depends on LHR value of filter medium, not on zeta potential of filter medium.

Abstract: Based on the classical free-electron theory, the mechanism of electroplastic effect is studied at a microscopic level. A method is presented for calculating the amount of metal’s flow stress for electroplastic effect. This calculation method takes into account the free electrons exchange energy with metallic ions with a current pulse applied and considers the energy cause the change of the dislocation Gibbs free energy of activation. The results indicate that the metal’s flow stress drop associates with an enhanced plastic strain rate. At last, the effects of current parameters and microscopic parameters on the metal’s flow stress for electroplastic effect are discussed.

Abstract: The form of blank holder and the manner of blank holder force (BHF) on the complicated parts forming are very important. The blank holder of rectangle box forming was divided long straight segments, short straight segments and corners. The forming process simulation of rectangular box was conducted by FEM based on explicit algorithm, including single-piece blank holder with constant BHF, single-piece blank holder with variable BHF, segmented blank holder with constant BHF, segmented blank holder with variable BHF. The results were analyzed according to the thinnest level of the parts. The displacement in the Z direction of blank holder in the simulation was considered, and the method of determining segmented variable blank holder force (VBHF) was proposed. Finally rectangular box was obtained by rectangular box drawing system of segmented variable BHF on the basis of the simulation result.

Abstract: In the paper, concrete on meso-level is taken as three phases composites consisting of aggregate、matrix and bond between matrix and aggregate. Model and arithmetic of Interface Element Method (IEM) is introduced and used to study the fracture characteristic and process of concrete under uniaxial load.

Abstract: In the fragmentation theory of T. Campanella et al, the local remelting of dendrite arms is induced by the solute-rich fluid flow. Based on this theory, the effects of linear EMS intensity and solute content on CET of steel are investigated. The conclusions are as follows: The criterion for dendrite fragmentation under linear EMS is derived based on dendrite fragmentation theory by T. Campanella et al. And the criterion is verified with steel experiments. It is valid for steel under the Linear EMS. Investigation is carried out on relation between critical volume fraction of solid and solute content at the time of dendrite fragmentation (CET occurrence). It is concluded that critical volume fraction of solid is small with low EMS intensity and it decreases with the increase of solute content (C, Mn). The reason is that it causes that flow in the mushy zone becomes small which leads to CET occurrence difficult.

Abstract: Emergency evacuation of large passenger station passenger terminal operations management is an important part of management. In this paper, it use legion simulation software, on the Beijing South Railway Station passenger emergency evacuation simulation test, first introduced the Legion simulation software and simulation process, followed by the design of the total number of 5000 and 10,000 people in different device configurations evacuation simulation program; re-use simulation software legion For each program the simulation analysis, the number of the simulation program evacuation and evacuation density optimization Finally, emergency evacuation measures and proposals for the reasonable development of passenger flow planning and organization of decision support programs.

Abstract: In order to abate fatigue fracture at roots of the first or the second hackle thread of bolt used for hydraulic press ,law of stress and load distribution in bolt threads suffered the axial forces were researched by using nonlinear finite element method.It was found that Peak equivalent stress in roots near axial force are abviously greater than these far away axial force when nut threads are in elastic range,but almost are equial to stress in roots far away axial force when 70% nut threads are in plastic region.Nut thread cutting to the fisrt two teeth can improve stress distribution in a bolt ,but these improvement recede quickly as plastic rigions of nut threads extend.

Abstract: Deformation often appears in castings during casting and heat treatment processes, which determines the machining allowance setting and the machining size distribution of product. The paper presents a novel method for integrated simulation of the deformation behavior of castings during casting and heat treatment processes with a unified finite element model. Firstly, analyze the deformation of castings during casting process with the model containing mold and casting, and update the geometry of casting after casting process, then analyze the deformation of castings during heat treatment process and the final geometry shape of casting before machining could be obtained. By the method, investigation on the deformation behavior of a hydro turbine blade casting during casting and heat treatment processes was carried out, and the residual stress distribution and geometry shape of the casting were obtained.

Abstract: At present there have rarely studies on internal force and deformation for rock-socketed piles of deep excavation. The current approaches still exist and have many deficiencies and all of them didn't consider the effect of rock-socketed length. Based on the theoretical mechanics analysis of rock mass resistance, the computing methods of ultimate resistance Pult is applied to the analysis of force balance of rock-socketed part, the paper has put forward the detailed procedure for computing internal force and deformation of supporting rock-socketed piles in view of the rock-socketed length, moreover, the influence of the stability of rockmass is comprehensive considered in this method. Finally, an example is analyzed according to the procedure, the calculation results show that the method is much feasibility. The internal force and deformation of the retaining piles computed according to the procedure mentioned above satisfies the stability of rockmass.

Abstract: By detecting microstructures and properties of Cu-W composites, effects of powder composition, sintering temperature and compacting pressure on sintered billets were studied, and sintering mechanism of Cu-W powders was discussed. Effective rules of process parameters have been preliminarily obtained: Sintered billets of Cu-40W and Cu-50W had a low density when compacted at 200MPa, sintered below the melting point of copper, and density, hardness enlarged with sintering temperature increasing; Hardness, density, electrical conductivity of Cu-40W enlarged with compacting pressure when compacted above 600MPa, sintered at 1100°C; But when compacted at 800MPa, sintered at 1100°C, Cu-40W sintered billets had a density of 11.37g/cm3, relative density of 99.6%, closed to the theoretical value.