Applied Mechanics and Materials Vols. 215-216

Abstract: To study the external flow field of a domestic heavy duty commercial vehicle, numerical simulation method was used in this paper, a hybrid of k-w and k-e turbulent model and polyhedron mesh was adopted to simulate the external flow field of the truck with three different front shape, and a comparative assessment was made to analyze the difference of the flow structure in the case of crosswind. The comparison analysis revealed that the top and bottom flow separation at the side wall of the truck was reduced due to the guiding effect of the truck nose, and the pressure at the leeward side of the truck was increased, which helped decreasing the pressure difference of the two sides, and alleviated the negative effect of the increased side positive-pressure area caused by the increased lateral area resulting from the elongated truck nose.

Abstract: In this paper statics analysis and optimization design are made for shovel of raking coal manipulator with ANSYS. On the premise of satisfying strength and displacement, improve structure performance further. In addition, theory basis is provided for whether shovel meets working conditions.

Abstract: Simulating and analyzing the kinematics model of double crank-slider mechanism with Simulink tools of MATLAB platforms.The mechanism is a system that its kinematic equations can construct the simulation model,and its initial position may determine the relevant parameters of the model,by this way can obtain the simulation results of the kinematic parameters.Finally,take the main transmission mechanism of the the platform printing machine as an example to verify the accuracy and effectiveness of the proposed method.

Abstract: Basing on an analysis on the motion cycle switching of yarn splicing device and tube changing device of an automatic twisting winder using ratchet-pawl clutch, this paper studies the self-locking conditions of the ratchet-pawl clutch, the rotation angle and revolution angle for separation of the pawl, the pawl escapement and the pawl disk locating device, gets the calculation method and design formulas for functional parameters of the ratchet-pawl clutch, and finds out the conditions for whole circle rotation and precise locating of the pawl disk.

Abstract: 3D CAD model retrieval has received a lot of attentions in the academic community. Most existent methods for 3D model similarity assessment focus on component models instead of assembly models. In this paper, an assembly model similarity assessment method is presented in order to find the similar assemblies model for design reuse. First, assembly model is described as component attributed relational graph. Then, the compatibility matrix between two assemblies is calculated, which serves as the measure of their similarity. Finally, the optimal matching under the measures is calculated using Hungarian Method. Experimental results show that this method is able to support the assembly similarity evaluation.

Abstract: Considering safety and reliability of interface between aircraft and artillery, aircraft need of increasing space of shell bands, but its range decreased by flight experimental results. It is enough to numerically simulate and calculate to aerodynamics of two projects (namely aircraft increased spacing bands vs. archetype aircraft) model in this paper. The simulation results show that big space of shell bands affect aircraft body’s coefficient of drag, and keep to flight experimental results. In keeping to big spacing bands at the same time, it is put forward optimization scheme that aircraft can reach to design range by adjusted tails shrink angle. When the tails shrink angle reached to six degrees, the big spacing bands aircraft’s coefficient of drag decreased obviously and pressure coefficient little increased to avail of improving aircraft’s range by a large of numerical simulations.

Abstract: In order to reshape the spherical sweet dumpling for other shapes such as flat triangle, flat spherical, etc., a kind of molding machine for sweet dumpling was developed. Three different molding principle schemes, such as the roller-extrusion molding, the pattern-plate plane-pressure molding, and the turntable with model-hole plane-pressure molding were putted forward. It took the roller-extrusion molding schemes as an example, the machine main work structure, transmission methods and so on were analyzed. Then to use UG software, the machine's overall design is completed.

Abstract: The type synthesis of torsional mass dampers (TMDs for short) as anti-galloping devices is very import for the safe operation of power grid. In this paper, the TMDs are considered as passive robotic manipulators, with the aim of introducing planar four-bar mechanisms into the synthesis of TMDs. By utilizing one planar four-bar mechanism or two planar four-bar mechanisms in a single TMDs, 6 TMDs with symmetrical structures and 18 TMDs with non-symmetrical structures are synthesized, which may improve the reasonable applications of the TMDs for the solving the anti-galloping issue of power grid.

Abstract: Take maximum power output of blade element as design target, establish a optimization model of variable pitch wind turbine blade. Using the adaptive genetic algorithm to search for to overcome the shortcomings of early maturity and poor stability, it can reach more close to the global optimum than the classical genetic algorithm. Use this method to design a 3MW variable pitch wind turbine blade, the results show that this optimization model is correct and the method is practical.

Abstract: In the field of spatial orientation, the rotational parallel mechanism is widely used. While the existence of coupling brings about the parallel mechanism some difficulties in kinematics and dynamic analysis, the development of control system, and so on. This condition restricts the application fields and effects of the rotational parallel mechanism. Therefore, this paper proposes a novel 2-DOF (two degrees of freedom) rotational DPM (decoupled parallel mechanism). The feature of the mechanism is described and their movement form is analyzed with screw theory. The proposition of the novel rotational DPM will enrich the configurations of the parallel mechanism, and the contents of this paper should be useful for the further research and application of the rotational parallel mechanism.