Applied Mechanics and Materials Vol. 472

Abstract: The complex force of the auger stem in soft coal seam is taken as the research object. Then the three-dimensional model of spiral pipe is established in the SOLIDWORKS software, and introduced into the workbench simulation platform of ANSYS software to simulate the stress distribution of the screw drill pipe in actual working conditions. According to the results of the analysis, the conclusion is that the stress concentration is around the pin hole of the female joint and the fatigue life of spiral drill pipe is 280.72 x 10 3 cycles.

Abstract: The new type worm pipe robot was put forward based on Stewart parallel mechanism by the method which move or rest platform is alternated. The kinematical model was set up by the method of coordinate transform for the robot in this paper, and the walking principle was analyzed when the robot moved in straight pipe and elbow. Further more the virtual prototype was made and kinematical simulation analysis had been accomplished. By the walking simulation when the robot moved in straight pipe and elbow it is validated that the walking principle established for the robot is correct. The robot can has bigger tensile draw.

Abstract: Take the rice and wheat combine harvester threshing device as an illustration, utilize the idea of modular design, adopt the method of functional analysis, the threshing device is divided into different modules. Combining the parametric modeling technology, and use Solidworks Software as Platform, the modularization design of the harvester is fulfilled by partitioning and combining the modules, which provides a solution to the fast allocation of different combine harvester.

Abstract: The object of this study is to utilize FE-SPH method to simulate the dynamic behavior of bioprosthetic heart valve during systole. Two kind of bioprosthetic heart valve numerical models are designed based on membrane theory, and they are represented by FE mesh, the blood is modelled as SPH particles. The interaction between the blood and bioprosthetic heart valve is carried out with contact algorithms. Results show that: when the valve leaflets are opening, compared with that of spherical valve, the stress and strain states of cylindrical valve are unstable, and the peak Von Mises is also higher, which high peak stress and its instability may induce the fatigue of valve. The valve opening time of columnar valve leaflets is longer than that of spherical ones, which reduces the blood ejection time. Above results indicate that spherical valve is superior to cylindrical valve. The FE-SPH method is capable of simulating the fluid structure interaction between the bioprosthetic heart valve and blood during the systole.

Abstract: This paper used the finite element software ANSYS to simulate the thermal assembly process of the roller sleeve of the HFCG160 roller press, and study the change of the temperature field. And then, comparing the simulation temperature with the test temperature, the results show that the simulation temperature is basically consistent with the test temperature, while there are slight biases on the individual points within a certain period of time. The main reason for biases between the simulation temperature and the test temperature is that the convective heat transfer coefficient is average during the simulation, which ignoring the convective heat transfer coefficient decreases with the decreasing of temperature.

Abstract: The modal analysis for rotating disk with pre-stressed in different high speeds were made respectively based on the finite element software of ANSYS. The each order natural frequencies and inherent vibration were revealed. The result shows that disc rotation speed increases, the each order natural frequencies will also increase, and inherent vibration corresponding changes. By introducing the disc frequency deviation factor, the effect of stress stiffing effect for the disc natural frequencies and inherent vibration were analyzed and found that relationship of a quadratic curve between disc frequency deviations and speed.

Abstract: We investigate the tensely-strained state of three-dimensional construction at the measured settlements of the foundation. The numerical model of the construction is developed within the limits of the theory of the plates bending and rectilinear rods, it allows to reveal dangerous places in the strength members particularly in the interfloor plate. The three-dimensional model of the dangerous area is developed, which allows to define the level of damaging the plates material. Settlements levels leading to first cracks and full destruction of the investigated area of the construction are defined.

Abstract: This paper studies the dynamics of a duopoly model with bounded rationality and nonlinear demand function. Based on the stability theorem and Jurys criterions, we prove that the model has two unstable boundary fixed points and a local stable Nash equilibrium. Then we depict the stability region of Nash equilibrium, and investigate the effects of output adjustment speed on the players profit respectively. Theoretical analysis and simulations show that higher output adjustment speed can result in chaotic variation of outputs, and that the Nash equilibrium is the optimal result of duopoly game. To improve the profitability of each player and achieve the optimal game result, we put forth a new scheme combined with the time-delayed feedback control and the limiter control to stabilize the output to Nash equilibrium. Finally, the numerical simulation is adopted to verify the effectiveness and feasibility of the above control scheme.

Abstract: On the basis of evolutionary structural optimization, the topology optimization for free layer damping cylindrical shell was studied. The checkerboard pattern problem caused by evolutionary structural optimization was solved by discrete independent mesh filter method. The programs of evolutionary structural optimization and discrete independent mesh filter method were made in ANSYS. The optimal topology configuration of free layer damping cylindrical shell was obtained and the effectiveness of Discrete Independent Mesh Filter Method was validated.

Abstract: The design for a double-axis double-rest CNC machining center is introduced by describing its key machine elements and machine tool design procedures. Then based on the theory of the multi-body system, the modeling process of the volumetric error model for the CNC machining center is expatiated and the result of the modeling is given. It is verified that the error of the machine tool is from three line error and three angular errors between structural units as well as the vertical error between axes. Finally experiments are carried out to evaluate the machining performance of this designed machine tool.