Applied Mechanics and Materials Vols. 201-202

Abstract: The contact analysis model of high speed centrifugal atomizer is created and stress distribution law is obtained by using ANSYS FEM software in this paper. The stress distribution along the axial direction is uneven, the stress of the small end of the taper is large and the stress concentration appears on both ends of the taper. In addition, the factors which influence the interference fit stress are researched and discussed. The interference fit stress is mainly influenced by the shrink range, while the influence from the friction coefficient is very weak. Comparing with the conventional design, the position and value of the stress and deformation of the parts can be known exactly and thoroughly by using the approach proposed in this paper. The method provides a very valuable reference to designing the best shrink range for engineering application.

Abstract: Uneven distribution of mass and temperature usually have important effects on the dynamic characteristics of rotary mechanism. Based on thermal-structural coupling theory, dynamic response analyses of the flexible rotor of centrifugal atomizer can be done by FEM. Considering eccentric quantity is caused by nozzle clogging and axial non-uniform distribution of temperature, the dynamic characteristics of the is studied; the response of mass unbalance and thermal bending or coupled the both is researched and compared. It is shown from the calculation that all of the three conditions have affected the dynamic characteristics of rotor system and the design can basically meet the stable operation requirement of the atomizer. The results can be applied to improve the design of the centrifugal atomizer. Developing more detail analysis to optimize the design in the future research.

Abstract: A rigid-flexible coupling model of sliding guideway working in powered turret for a new developed multifunction NC lathe is built up based on Solidworks, ANSYS and ADAMS. A solid model of is built up by the 3d-Modeling software Solidworks, and then the built model of sliding guideway is imported into finite element analysis software ANSYS to analyze elastic deformation. A mnf file of model generated by ANSYS which is a flexible body is fed into ADAMS to replace the rigid body of assembly. A dynamics simulation is conducted by considering a typical cutting processing like milling on lathe, the deformation of fixed guideway in working condition is checked. The analyzed results show that it is more rational and accurate to apply rigid-flexible coupling dynamic simulation for analyzing such mechanical system and this type of sliding guideway used in powered tool turret can stand up with cutting load and can meet the requirement.

Abstract: It was performed nonlinear finite element analysis for K-shape eccentrically braced steel frames on link beam. Analysis indicates that the strength, rigidity, ductility and energy-dissipation performance of K shape eccentrically braced steel frames deteriorate differently with the length increase of link beam. The shorter the link beam is, the larger plastic deformation of it, so it makes plastic collapse easily, while a long link beam has a poor cyclic behavior. At the end of this paper, compared with the experimental results show that the finite element method is feasible, the results can provide a reference for the engineering design and related research.

Abstract: The dynamic electromagnetic compression technique of metal tube which can be used for study of collapse with cylindrical symmetry like the thick-walled cylinder (TWC) technique is introduced. 3D simulations by multiphysics ANSYS finite element code are used for metal tube compression, and the magnetic flux density, displacement, and strain in process are obtained. The influence of the sizes of the tube is considered in the tube compression. The finite element analysis results show that the specimen which has small height or thinner thickness is easier to compress than the big one. The study can offer valuable information about the process analysis of metal tube electromagnetic compression and specimen design.

Abstract: According to the generating method theory, noncircular gear with all convex pitch curve can be processed by generating, author designed noncircular gear tooth profile, described a method of precisely calculating noncircular gear tooth profile. And proposed automatically optimizes the noncircular gear tooth profile meshing curve part separately by the identical rack cutting tool different side envelope. Through rack cutting tool along two gear center of rotation segment deviation pitch curve change modified quantity to avoid tooth undercut, realization nonzero modified. The driving gear and the driven gear tooth profile meshing curve part separately by the identical rack cutting tool different side envelope, guarantees when meshing zero clearance. The noncircular gear machined by this method has been used in real machine, which verifies the feasibility of the method.

Abstract: The strain smoothing technique is employed in the natural neighbor Petrov-Galerkin method (NNPG), and the so-called smoothed natural neighbor Petrov-Galerkin method is proposed and studied. This method inherits the advantages of the generalized MLPG method and possesses the easy imposition of essential boundary condition and the domain integration is completely avoided. In comparison with the traditional NNPG, the smoothed natural neighbor Petrov-Galerkin method can obtained more stable and accurate result without increasing the computational cost.

Abstract: There is still lack of effective modeling and simulation method for complex electromechanical coupling system. Modelica is a multi-domain unified modeling language to solve the modeling and simulation problems of the complex and heterogeneous physical systems. Dymola is a Modelica-based modeling and simulation platform for the complex physical systems. In this paper, the dynamics model of the permanent magnet synchronous motor (PMSM)-precision reducer system is established using Lagrange-Maxwell equation. The simulation model of this system is set up with Modelica language. The simulation of the system is realized in Dymola. Results show that the system can respond to good static and dynamic characteristics under a given speed for different loads. The dynamics model of the PMSM-precision reducer system can be further used in system control and optimization. The proposed modeling and simulation method based on Modelica may be commonly applied to other complex electromechanical systems.

Abstract: The dimension quality of sheet metal subassembly（SMS）, which is usually assembled in the multistage process, has serious effect on its performance. Based on the multistage transmitting model of dimension errors of SMS, this paper detailedly analyzed the dimension errors of SMS in locating phase, over-locating phase and springback phase, and also simulated their dimension errors by Matlab and FEM, and finally predicted the assembly dimension errors of aeroplane wainscot subassembly sample.

Abstract: The formation and lubrication mechanism of boundary lubricating film were discussed. The boundary lubricating film includes adsorption film and chemical reaction film, and has respective temperature operating range. The adsorption film adsorbed in metal surface by Van-der Wads, and the parenchyma is the external friction between adsorption molecule layers. The chemical reaction film is made by the reaction between metal and extreme pressure additive in base oil, and the anti-wear capability is realized by the low-melting point eutectic alloy. The temperature is regarded as a judge criterion for failure of boundary lubrication. The failure model for boundary lubricating film is established. According to the failure model, the failure criterion proposed is effective by analysis of the spiral bevel gear using the finite element method. These results provide a basis for the application of boundary lubrication.