Applied Mechanics and Materials Vols. 635-637

Abstract: Additive Manufacturing (AM) is the digital manufacturing technology by which products are fabricated directly from computer models by selectively curing, depositing or consolidating materials in successive layers. The technology has provided an opportunity to rethink the methods of product design to maximize the product performance through the synthesis of material compositions, structure, and sizes. This overview is created to relate the unique capabilities of AM technologies and discuss the methods of product design. Finally, the current problems and difficulties in this field are discussed in this paper, and this paper proposes the development direction of the product design for additive manufacturing in the future.

Abstract: The article first systematically expounds the working principle and deficiencies of spring buffer, spring - hydraulic buffer, compressible liquid buffer, and other typical buffers. And then detailed introduces the generation, working principle and outstanding features of new material buffer. Finally, according to the characteristic of traditional buffer that performance parameters are immutable, presents a soft mounting buffer that performance parameters can be changed of intelligent, provides theoretic and technological reference of Overhead Weapon Stations for its development design and modification upgrade in China.

Abstract: For the multi-material topology optimization problems which take structural minimum compliance as the object, based on the weight function and optimality criteria, an improvement to the original alternating active-phase algorithm is achieved in establishing and calculating the mathematical model of multi-material topology optimization problems. Simulations of numerical examples are implemented respectively by the improved alternating active-phase algorithm and the original algorithm. It can be found that the minimum compliance obtained by the improved algorithm is generally lower than that obtained by the original algorithm in each numerical example, whereupon the feasibility and efficiency of the improved algorithm are manifested.

Abstract: The amphibious vehicle is a special vehicle, which has performances of land vehicles and ships. Compared to the ships, amphibious vehicle can be sailed fast in the water and driven flexibly on land. Therefore, it has a wide range of applications in the fields of military and civilian. The status of dynamic research of amphibious vehicle is described in this paper. The current situation of dynamic research is presented firstly. The methods of establishing the dynamic model when amphibious vehicles travel linearly and turn were included. Then the modes of propulsion when amphibious vehicles sail in the water are introduced. In the end, the paper summarizes the methods of establishing hydrodynamic model of amphibious vehicles, which are used to analyze the resistance of amphibious vehicles.

Abstract: The key of studying the nonlinear system of the stationary period solutions by the HBM is solving a group of higher order multi-degree-of-freedom nonlinear equations. Aiming at this difficulty, this paper can easily get a higher harmonic balance truncation order expression of solution using a powerful symbolic computation software, and avoid the tedious derivation process. And the main subharmonic response range was accurately obtained by the EACM for solving the nonlinear equations. Meanwhile, the chaotic region was estimated through subharmonic cascade regions combined with the bifurcation of the Feigenbaum rule by solving the system. And, numerical results calculated by the Runge-Kutta method were given to verify the results of the period doubling bifurcations and chaotic region obtained by this method. It has been shown that they are in good agreement.

Abstract: The angular deformation and torsional deformation are investigated by FEM on open front press with nominal press force of 1600kN. The FEM mold of press is established by processing contact, constraints, and loads. The angular deformation of frame and torsional deformation of slide are analyzed based on the analyses of distribution of equivalent stress and deformation. The influence work force of open front press to angular deformation and torsional deformation are obtained.

Abstract: Optimization model and solution method are developed in the present paper to improve the design of the hatch door mechanism of a regional airliner. The real motion trajectory of the hatch door normally has deviations from the ideal trajectory due to existence of machining errors. In order to decrease such deviations, a bi-level optimization model is developed for the design of the size tolerance limits of the key parts. The design objective is to minimize the extremum deviation of the trajectory of the objective point of the hatch door. The extremum deviation is obtained by solution of the inner-level size optimization problem for the fixed size tolerance limits. The optimization models for motion control of the hatch door mechanism are solved by the response surface method.

Abstract: This paper investigates the dynamic characteristics of 600MW turbo-generator stator core, including the bending modes, the torsional modes, the elliptical modes, the axial modes and the triangular modes. The magnetic pull formula under the steady-state condition is firstly deduced, based on which the pulsating characters and the core deformation due to the pull excitation are analyzed. Then, the finite element (FE) model of the stator core is set up and imported into ANSYS Workbench to calculate the natural frequencies and the vibration modes. Finally, the calculation is verified via comparing with the experimental data in the published papers. It is shown that the first natural frequency is much larger than the excited working frequency, which means the stator core is in a safe operation condition. The calculation proposed in this paper accords well with the experimental data obtained by other researchers.

Abstract: During construction, some large equipments should be connected with the equipment above. The traditional way is to use cranes for assistance to lift the equipment below up to connect with the equipment above. But for some equipments with large weight and limit operation space, traditional way will be completed with strict operation requirement and high cost. In addition, sloshing may happen during connection. The paper designs a circular jacking method according to actual construction situation to reduce the shortage in the traditional way.

Abstract: A heavy-load positioner with series-parallel mechanism was put forward according to the heavy-load positioner’s task demand. Two rotational DOFs were realized by the spherical 3-DOF mechanism with a restricted embranchment instead of traditional gear-driven mechanism, the other by the serial part. The mechanism has the advantages of large workspace, good flexibility and high stiffness-to-weight ratio. The kinematics, statics and singularity of the positioner mechanism were analyzed. The mathematic model of the positioner mechanism was established. Combining the workspace demand of the positioner, dimension optimization of the mechanism was researched. Finally, the kinematics,statics and the singularity analysis of the positioner mechanism was verified through virtual prototype designed with one group of satisfied dimensions.