Advanced Materials Research Vol. 529

Abstract: This research presents a vacuum driven peristaltic micropump with three normally closed valves which is controlled by the operational frequency on the electrical magnetic valve. The new peristaltic pump is constructed with three laser-defined structural layers made only of PDMS material and by MEMS (micro-electro-mechanical-systems) fabrication technology. The liquid is driven by the sequential deflection of membranes which are positioned between the gas layer and fluid layer. In order to test the performance of the micropump, the influence of various control and geometric parameters are explored. The experimental results show that the flow rate of micropump can be easily operated by controlled the driving signal frequency on the EMV and the applied vacuum pressure. The optimized operational condition and geometric parameters of the micropump are obtained by experiment.

Abstract: Modern powerful finite element analysis software packages such as ANSYS are now not only an analysis tool but a design tool as well. The new technology makes the mechanical design quantified precisely combining with several physical fields in one. The paper briefly introduces the basic theories and basic steps of solutions of finite element analysis. After introducing the application of ANSYS software, the author proposes some effective solutions to this complicated engineering analytical, which is of practical significance of reference.

Abstract: Considering the effect of non-linearity of geometry and material to the arch bridge, this paper creates the FEM model of the whole bridge, uses the transient analysis method to analyze the seismic behavior of the main bridge of GuCheng Great Bridge independently under the action of Tianjin seismic wave. To give some suggestion on the design of rigid-tied rigid-arch rib CFST arch bridges by studying the seismic behavior of each component on the different positions with the seismic wave of different orientations.

Abstract: Used the Solidedge to bulid the solid model of the Vertical Shaft Impact crusher’s rotor, then it is imported into Ansys for modal analysis, get the former twenty frequency and vibration model, through the twenty color vibration models and vibration animations attained from analysis, the rotor’s dynamic properties and weakness area could be detected directly, to set up the foundmental theory for the structure design.

Abstract: With the rotor structure ofturbopump, using a one-dimensional finite element method, considering the mass of shaft, gyroscopic effect and influence of shearing deformation,establishedtheone-dimensional rotor dynamics finite element model, calculated its six rank of the critical speed, and compared the gyroscopic effect and mass of shaft to the influence of the critical speed turbopump, and the results show that, considering the mass of shaft there is a slight decrease of critical speed value, and gyroscopic effect on critical speed calculation has a significant effect, therefore, gyroscopic effect must be considered in the design of turbopumps.

Abstract: This paper investigates a three-dimensional finite element model for the cross-wedge rolling process has been used to characterize the workpiece material stress and deformation behavior. Considering the characteristic of cross wedge rolling, the static implicit FEM program is selected. To simulate all forming stages in the cross wedge rolling process, dynamic adaptive remeshing technology was applied. Examples of numerical simulation for strain, stress distributions and rolling load components have been included. The stress distributions in the cross-section of the forming workpiece are analyzed to interpret fracture or rarefaction at the center of workpiece. The computer codes in finite element method can be used for a large variety of problems by simply changing the input data.

Abstract: Recently, our research team has been considering to applying shape memory alloys (SMA) constitutive model to analyze the large and small deformation about the SMA materials because of the thermo-dynamics and phase transformation driving force. Accordingly, our team use simulations method to illustrate the characteristics of the model in large strain deformation and small strain deformation when different loading, uniaxial tension, and shear conditions involve in the situations. Furthermore, the simulation result unveils that the difference is nuance concerning the two method based on the uniaxial tension case, while the large deformation and the small deformation results have huge difference based on shear deformation case. This research gives the way to the further research about the constitutive model of SMA, especially in the multitiaxial non-proportional loading aspects.

Abstract: This paper studies the estimates and control of strictly contact diffeomorphisms in contact dynamical system. By constructing reparameterizing methods for contact system and using some perturbation techniques in Hamiltonian mechanics, this paper proves that the two norms of strictly contact diffeomorphism coincide under a certain condition and gives a variational descriptions of the tine one strictly contact isotopy.

Abstract: In order to enhance position accuracy of robots, the precise error model is established by applying homogeneous matrix without any differential or partial derivatives required in other methods. An articulated picking manipulator with four-degree-of-freedom is taken as example to analyze the position accuracy affected by errors of geometric parameters (link length, link offset and twist angle). Furthermore, an error compensation algorithm based on error model and inverse kinematics is proposed and applied to the picking manipulator. Experimental simulation was carried out for verifying the feasibility of the presented algorithm, and results show that the maximum position errors in x, y, z axis have declined from 3.2369mm, 9.5583mm, 1.002mm to 0.1334mm, -0.0488mm, -0.001mm after compensation, which could greatly improve the position accuracy of the picking manipulator.

Abstract: Plates are widely used in the machine tool structure. Based on the differential equations of flexural free vibration of a thin plate on Winkler elastic foundation, its dynamic fundamental solutions and the dynamic boundary integral equations are established. The solving methods of the corner point problems are given out. The quadratic elements are used to discretize the boundary integral equations and the receptance mtrix equations of a thin plate on Winkler elastic foundation are established. The fequency scanning method is used to obtain the natural frequencies of the thin plate on Winkler elastic foundation. Case studies showed the effectiveness of the proposed BEM dynamical analysis, which can be also used in the dymical analysis of joints in a machine tool structure.