Applied Mechanics and Materials Vols. 494-495

Abstract: The finite element method (FEM) has been used for an independent analysis of forklift truck components. However, the accuracy of such an analysis may not be reliable because it does not in view of the interaction of the forces transferred between components. Here, we analyze the mast system as a whole using an FEM based on a simulation chain method employing MPC184 units, as well as a method to analyze components independently. Both methods are used to simulate the stress of the upper beam of the inner mast. We then compare the maximum stresses calculated using the two different methods under three sets of working conditions. The data show that, in comparison with theoretical results, the average error rate of the overall analysis method was 4.71%, while that of the independent analysis was 33.3%.

Abstract: With the new equipment research preparation put into use, in order to ensure special purpose forces, in the existence of a large number of new equipment nonstandard parts. These non-standard parts in the various aspects of the new equipment play a great role. This topic-based VIRTOOLS 5.0 software to establish a non-standard parts library in new equipment, new equipment, used to strengthen the management and maintenance of non-standard parts for the maintenance of armed forces provide a solid guarantee. Meanwhile, from the user maintenance reality, virtual assembly of non-standard parts, non-standard parts for the maintenance provide effective protection.

Abstract: Hot plastic profile produced by extrusion die is cooled down and calibrated by calibrator. Therefore, the cooling and calibrating ability of the calibrator directly influence the quality and output of the profile. The key is to design the distribution of cooling channels in calibrator. By analyzing the heat transfer process during cooling in calibrator, the cooling process of plastic profile in calibrator is simulated. Based on the finite element analysis results, the optimization objective is established to obtain the cooling efficiency and uniformity of each node in the profile cross sections of the calibrators exit and finish the optimization design of the cooling channels positions.

Abstract: The surface machining is more and more in modern manufacturing, it is able to machine the high precision surface by CNC machine tools, but there are many cutting errors yet. To reduce the cutting errors in surface machining effectively, the paper analyzed the errors of surface machining by flat milling cutter on theory, it found the main reasons of cutting errors in machining the surface, and got the method to compensate the errors, so it provided the theoretical basis of compensation algorithm of cutting errors in the machining the surfaces.

Abstract: Active magnetic bearing (AMB) system is a complex integrated system including mechanics, electronic and magnetism. In order to research for the basic dynamic characteristic of rotor supported by AMB, it is necessary to present mathematics method. The dynamics formula of AMB is established using theory means of dynamics of rotator and mechanics of vibrations. At the same tine, the running stability of rotor is analyzed and the example is presented in detail.

Abstract: The thermal stress analysis of car exhaust manifold is one of the hot research issues. The finite element model of QiRui exhaust manifold was established. Temperature field was gained by using numerical simulation, by mapping the above result as boundary condition of exhaust manifold; the distribution regularity of the thermal stress of QiRui exhaust manifold was gained. The analysis result shown that there serious stress concentration between the reinforced rib and exhaust tube, the maximum stress reached to 330Mpa, which is high enough to destroy the tube. By improving the rib structure, the maximum stress can drop to 280Mpa, and the stress distribution also smoother than the original.

Abstract: In this paper, an intelligent magnetoelectroelastic thin plate is coupled with a transverse magnetic field and uniformly distributed load. Considering the von Karman plate theory of large deflection and the geometric nonlinearity, the damping Duffing equation is obtained. Using the Melnikov function method, the Chaos condition of the system under the Smale horseshoe transformation is obtained. The bifurcation diagram, the wave diagram of displacement, and the phase diagram are shown here by the numerical analysis. The simulation results show the complex nonlinear vibration characters of the intelligent magneto-electro-elastic thin plate.

Abstract: Organizational field is a vital parameter in quenching process. the phase changing temperature of steel U71Mn was got based on its CCT curves. Through cooling curves of several key points, the cooling rate at phase transition point was calculated. By comparing with every microstructures critical cooling rate, the final cooling microstructure was predicted. Relative tests showed that the prediction was reasonable.

Abstract: Keeping exhaust gas temperature constant in oxygen enriched and flue gas circulating Micro Gas Turbine, Numerical Research is carried on to study inlet temperatures influence on combustion characteristics. Simulation shows that along with increase of methanes temperature, combustion efficiency increase slightly, uniformity coefficient of outlet temperature decreases, total pressure recovery coefficient decreases, content of carbon monoxide and methane in outlet gas decrease. However, when inlet methanes temperature exceed 100 °C, content of NOx increase rapidly in flue gas. The simulation result supplied reference for design of oxygen enriched and flue gas circulating combustor.

Abstract: This paper studies the experimental research on dynamic characteristics of the damping rubber in high elastic fastening by the electro-hydraulic servo movement tester. Based on a hypothesis superposition theory of nonlinear elastic restoring force and nonlinear damping force, a non-linear dynamic mechanical model is proposed. The dynamic stiffness and damping parameters of the rubber are obtained in different deformation conditions based on the dynamic mechanical model. The dynamic stiffness is analyzed, and the results show that dynamic stiffness is closely related to excitation frequency and amplitude. Furthermore the dynamic stiffness is analyzed under different free surface of rubber components by using FEM. That also reveals the changeable characteristics and affected factors of the damping rubber of the high elastic fastenings in large distortion condition.