Applied Mechanics and Materials Vols. 633-634

Abstract: Based on the cracking phenomenon of the floor of the light truck cab, white body finite element model of a light-truck cab is established, with which computational and experimental modal calculations and analysis are conducted.Through the force relationship between tilting mechanism and the cab, the structure strength analysis of the main components of the cab is carried out, the weakness or the position of the components of the cab is found, which Provide a reliable basis for improving the structure of the tilting mechanism or the cab.

Abstract: Quadcopter is a novel appearance, superior performance VTOL aircraft, which has a simple structure, flexible operation, high load capacity and other characteristics, have important civilian and military value. This paper describes the status of research the unmanned aircraft, the key technology and application prospect and gives the overall design of quadcopter frame. First, according to design, we should build quadcopter frame models, then analyses the frame with ANSYS finite element software. Select the necessary materials and structures that meet the strength and stiffness the system needs.

Abstract: The reliability of formwork support is directly related to gob-side entry retaining success. In this paper a dual function of supporting and filling formwork support is designed. Use SolidWorks software build 3D modeling and virtual assembly, The establishment of a movement model of the anti-four-bar linkage formwork template using numerical methods and get the motion trajectory of the roof. It has been verify that the anti-four bar linkage design of the hydraulic support is feasible.

Abstract: Houdingxiang No. 3 Bridge is a 4-span steel box girder bridge. After the incremental launching construction, the bridge has to be lowering to the support bear, the lowering construction is divided into three stages. At first the launching equipment is used to lower 80cm, the next the jack with load capacity of 180 tons is used to lower 110cm, finally three-direction-jack with load capacity of 200 tons is used to lower 20cm. mechanical analysis on lowering the bridge used jacks with the load capacity of 180 tons and 200 tons is respectively carried out by FEM software ABAQUS, and the result shows that this kind of lowering technique is safe and reliable, it meets the construction demand.

Abstract: According to the original design, the strength of the web should be able to withstand the support reaction force during launching. While in the process of pushing construction, local buckling of the web on the support occurred. In view of the above situation, in this paper, establishing solid models for finite element analysis based on the ABAQUS software, comparing with the result of original design, and it was found that there existed some differences between simplified model and constraint condition of the design and construction. That is, the original design did not consider the deformation cased by beam segments arching, which caused the bearing area reducing and stress concentration, this was unable for the design software based on beam elements method to analyze. This problem could be solved by elevating the arching supporting. The analysis showed that elevating the adjacent supporting could reduce the maximum stress in the structure effectively by sharing the loads.

Abstract: The turbofan double-rotor engine with afterburner, as a certain type of aero-engine, often presents itself with vibration fault problems in the process of trialing run in the ground text and installed the work process of state, which will affect test the factory qualified rate and the flight mission seriously. In this paper, we mainly adopt the order analysis method to find out the reasons of the engine's vibration hazard from its vibration signal, and then make pertinence measures to solve vibration fault problems, which are combined with vibration test and analysis system of the ground text in the process of actual application. The results of the paper analyze the problem of engine vibration fault effectively and reduce the incidence of engine vibration fault, So as to increase the qualified rate of the engine in the ground test.

Abstract: For modern long-span bridges, both the optimization of aerodynamic shape and the increase of torsional stiffness according to the result of the wind tunnel experiment could avoid the flutter instability.Vortex-inducedvibration with relatively large amplitude happens easily at low wind speeds. In this paper, based on wind tunnel experiment, by studying on the vortex-induced vibration characteristics of a long-span suspension bridge with single cable plane, aerodynamic measures for easing the vortex-induced vibration are given.

Abstract: The sponge membrane winding quality depends on the tension intensity and stability during the winding process. Taking the problem of winding system at dynamic procedure, this paper analyzed the dynamic relationship among velocity, tension and diameter of winding coil. On this basis, the design controlled invariable tension via changing the RPM of the motor and the PID controller ,the feed-forward decoupling controller also be utilized to compensate the tension simultaneously via adjusting the RPM of the motor. The simulation presents that the design has good dynamic responses and strong anti-interference capacity.

Abstract: A novel design method based on layout evolution of the periodic micro unit cell of the metamaterial is presented for improvement of the mechanical behavior of the composite structure. The macro properties of the metamaterial depend strongly on its microscopic layout, and hereby may possibly be improved by microstructural design. Topology optimization model and the solution method based on inverse homogenization process are developed to find the best layout of the microstructure. The proposed method may be applied to improve the static and vibro-acoustic behavior of the structure, which is validated by several numerical examples.

Abstract: The low-stiffness aircraft skin is easy to deform during the positioning process. This paper presents a method of positioning error analysis for the aircraft skin. The positioning error analysis model is divided into two parts: rigid error analysis and flexible error analysis. For the rigid part, the deterministic locating method is applied to analysis the position error of the key characteristic point according to the production errors. For the flexible part, a static equilibrium equation of the skin is used to describe the relationship of the contact forces. And based on the principle of minimum complementary energy and Coulomb friction law, a nonlinear programming function is built to solve the passive contact forces and the skin deformation in each step. This method is more effective to describe the positioning process and obtain the positioning error.