Abstract: In order to realize the rotation of permanent magnet synchronous motor and to carry magnetic flux density analysis of motor at 3-phase voltage load out, a set of ANSYS secondary development programming method with APDL is proposed in this paper. In this programming method, firstly, the rotational angle of the rotor at any time is calculated by two parameters of time and rotational speed. Secondly, the 3-phase voltage load at corresponding time can be got by two parameters of time and the 3-phase voltage frequency. Finally, according to the rotational angle of the rotor at any time and the 3-phase voltage load at the corresponding time, the whole process of the motor rotation is realized with ANSYS loop statement. This programming method solves the difficult problem that the rotor doesn’t rotate for ANSYS magnetic analysis and the magnetic flux density of permanent synchronous motor can be calculated more exactly.
Abstract: 18The traditional interfered muffler has narrow noise elimination frequency range.It has large noise elimination volume only at contracting frequency part. When noise frequency is far lower than contracting frequency, the noise elimination volume will fall rapidly .Designing a composite muffler based on the principle of gas convection, sound wave diffraction, sound reflection and so on. The muffler is mainly used for noise caused by pneumatic tools. Test shows that without affecting the work performance of pneumatic tools, the muffler can be 10-12dB noise reduction, which is worthy applying.
Abstract: The gear structure is equivalent to disposed as a circinal plate, and also, reference circle cracks of gear are simulated by setting the arc direction crack. Because of the appearing of crack, it will divide the whole circinal plate into some areas, and set different polynomials of vibrational flexibility in every area, then using District Technology and Rayleigh-Ritz method, the dynamical characteristic of circinal plate with arc direction crack is analyzed, the influence of the type and size of crack on dynamical characteristic(natural frequency, modal shape etc.)of circinal plate are deep studied. On this basis, making use of Finite element method, the first some order mode of the acoustic character of cracked plate are investigated using discrete Rayleigh integral, and the distribution of sound pressure on the r=0.5m sphere surface is obtained. At the same time, the influence of different depth of crack on acoustic characteristic of gear disc are discussed, and the rule of influence of crack on radiated acoustic field is given out. This result shows that the influence of crack on radiated acoustic field of circinal plate with the increase crack depth is increscent. These provide a theoretic foundation for gear fault diagnosis using the dynamic and acoustic method in engineering.
Abstract: Zeng Xiangwei researched the shuttle-type passive control system of pressure pipeline. He provided new technologies for specific media (such as Chemical industry, natural gas), specific environment (such as desert, forest) and operating system (such as water hammer, pulse). The significant technical difficult problem of the petroleum chemical industry, offshore platforms, nuclear power, defense, and other projects were solved. And these control components can work safely and reliably in 20 years. And this control system achieved complete-control or partial-control without outside power source. The shuttle-type passive control system of pressure pipeline expected to extend to the pressure pipeline system
Abstract: This paper investigates and analyzes the performances of several types of tuned mass damper (TMD) including common single TMD(STMD), multiple tuned mass dampers (MTMD) and dual tuned mass dampers (DTMD) on the machining chatter control. Considering the special nature of the machining stability problem, the optimal design parameters of the dampers are defined as those that minimize the magnitude of the real part of the FRF of the damped machining system. This paper demonstrates the performance of the optimally designed different TMDs for machining stability improvement by calculating the stability diagrams for the turning processes. The calculation results show that a more than 60% improvement in the critical limiting cutting depth can be obtained for the optimally designed MTMD (2 TMDs) compared to the optimally designed STMD, and a more than20% improvement for the optimally designed DTMD compared to the optimally designed MTMD(2 TMDs).
Abstract: The exploitation and application of recycled concrete are more and more extensive in latest years. But the research on the mechanics characteristic of recycle concrete under cyclic loading is very little. Six types of recycled concrete specimens were made in laboratory. After they were cured for a certain age, we have made a series of cycling loading tests on them. In the tests the maximum and minimal stress ratio, the loading frequency and loading waveform were all considered. The mechanics characteristic of recycled concrete under static loading and cyclic dynamic loading were contrasted. After analyzing the test results, we could get that the maximum stress and minimal stress ratio, the loading frequency and loading waveform influenced the unloading and loading modulus of recycled concrete directly in the tests, and the fatigue life of recycled concrete changed with the loading method.
Abstract: The research is conducted on the tank of semi-trailers which is made of steel by using the method of Finite Element Analysis. The optimized result indicated that the mass of the tank structure reduced by 9% on the premise that the intensity and the rigidity request of structural property is satisfied, and the dynamic characteristic also meets the requirement. It is the foundation to reduce the cost of manufacture and improve the operational effectiveness of user.
Abstract: Various elements in planetary gear reducer design are discussed. A multi-objective optimization model is created. The model requires the minimum volume and the maximum contact ratio. The method of multiplication and division is used to solve the multi-objective problem, and the method of feasibility enumeration is used to handle the discrete variables. The results show that the optimal solution meets the actual requirements.
Abstract: In recent years, three optimal methods, size, shape and topological optimization, have been widely applied to the automotive component design and significant success have been achieved. However, most of the optimizations are limited to deal with the individual component of the truck. Because there exists the complex coupling relations between components under the assembly environment of the truck, it is difficult to deal with the component design by using the above three optimal method and it is necessary to develop a more effective method for solving the complex optimal problem under the assembly environment of full truck. To this end, the paper introduces the modal stiffness concept and develops the modal stiffness contributions of components to full truck which can identify which components are the key ones for controlling the modal frequencies. The present method is applied to a full truck analysis. The results obtained show that the proposed method is effective and the computation process is straightforward. The results can be directly used to improve the component design of full truck as a valuable guide.
Abstract: The piston is a key part of engine,working in high temperature,high pressure and high load of harsh environment;Besides, periodic mechanical load and heat load work on it.Firstly,use the software UG to set up a geometry model of the piston;then use the ANSYS to set up finite element modle.We can learn about the total deformation with thermal load so as to find out the dangerouse and thermal stress points and provide theory for improving and optimizing structure of piston after mechanical load is added to the piston and coupling analysis is carried out.