Applied Mechanics and Materials Vols. 182-183

Abstract: During handling airplane low-rigid parts, it often horizontally hanger it with rope or sling. Combined with frictionics, this article analyses the force in vacuum sling of aeronautical low-rigid parts and gets the corresponding conclusion to design hangers for reference.By establishing finite element model, the deformation of hoisting is static analysed by ANSYS.The research results is to provide necessary conclusions in effectively resolving the optimization of designing of vacuum lifting system.

Abstract: A nonlinear finite element model of transmission tower-line coupling system including transmissions, towers and insulators is established based on ANSYS in this paper. Based on the second development at the ANSYS computing platform, finite element model of a Tower-Line Coupling system was established. The approach is applied to study intial shape of Tower-Line Coupling System. With the comparison with classical test cases, the approach was validated, performing high computing efficiency.

Abstract: In order to obtain geotechnical engineering material mechanical parameters correctly by using back analysis and overcome shortcoming of ordinary Particle Swarm Optimization, Improved Particle Swarm Optimization (IPSO) algorithm is developed on the aspects such as Stretching Particle, Metropolis Algorithm and adaptive weight updating .at the same time, the algorithm is compared with Catastrophe Particle Swarm Optimization Algorithm (CPSO) and Quantum Particle Swarm Optimization Algorithm(QPSO). Also result of back analysis was compared with that of Ultrasonic Testing and that of mixed-model of dam monitoring. The analysis shows that IPSO has better performance than that of PSO and CPSO, and considerable performance with QPSO.

Abstract: In this paper, with the ANSYS, stress distribution and safety factor of crankshaft were analyzed by using 3D finite element method. The results show that the exposed destructive position is the transition circular bead location of the crank web and the crankpin. Maximum stress is 118 MPa. Safety factor is 2.72. Maximum deformation is 0.773 mm. Crankshaft satisfies the design requirement.

Abstract: Table tennis, as one of the most popular sports in China, has grown considerably since its developed in the 19th century in England. The biomechanics of the research methods in many sports has been widely used, for understanding of sports and technology and improve sports played an important role Fast break and curving ball technology is this game’s core technology. In this study, we based on fast break and curving ball features of kinematic to reveal the table tennis forehand techniques. Eight male volunteers were participated in this tests, the speed of the racket during the playing was recorded through Vicon Motion Capture System. The action was divided into three major phases: back swing, attack and follow through. At the end of back swing stage, break and curl technologies, the speed parameter shows some differences. While the peak speed in ball contact frame, the speed of curling ball was significantly higher than the fast break. Further study could be carried out in detailing analysis at sub-stage of the action for integral considering.

Abstract: Latticed soil nailing support is a new type of revetment structure, which combined lattice support and soil nailing. It effectively improves the global stability of the foundation pit. Currently, the theoretical research about this supporting method is still not consummate. In this paper, on the basis of soil mechanics and code, the stability of latticed soil nailing support are analyzed by the theory of the retaining wall, soil nail and the model of supporting piles. Then calculate the displacement in the limit state by elastic fulcrum method and the instantaneous displacement by layer-wise summation method. The total displacement can be calculated by the combination of the two displacements above, which is between 3.38mm and 15.43mm and close to the measured data. Simulate excavation and supporting process of the pit by finite difference method, analyze the mechanical property and displacement of latticed soil nailing support. Thus the theory of the calculation method to this supporting model is obtained, offering a reference for the similar projects.

Abstract: This paper presents a general algorithm for topological optimization of the incompressible Navier-Stokes fluid flow based on a level set method. This is a direct extension of our previous work on Stokes flow of such problems. First we obtain the shape sensitivity analysis using the material derivative concept and adjoint variable technique, and then we couple the shape sensitivity analysis result into the level set function as the advection velocity. Since the level set method is implemented in an Euleran framework, the computational cost of the proposed algorithm is moderate. A Benchmark example is provided to illustrate the efficiency and validity of this method.

Abstract: A kind of 3-RPS and 3-DOF parallel robotic mechanisms is used as motion-sensible-platform of gun training simulator to implement the motion simulation. Its dynamics is analyzed and driving force of joint is gained. This paper introduces the study on motion generation of gun training simulator. The moving model of gun is established on the basis of the model of vehicle. We solve the pose of gun by applying the theory of homogeneous matrix. In order to ensure actuators moving at a preset speed and enable the motion-sensible-platform to perform a real-time moving posture simulation of a wheeled gun vehicle in running, the speed equation of actuator is given. The feasibility of models was tested through the simulation experiments. All of these works are beneficial to optimize design and control realization of motion platform structure.

Abstract: Fuzzy C-means clustering algorithm(FCM) is sensitive to its initialization of value and noise data and easy to fall into local minimum points, while it can’t get the global optimal solution. This paper introduces gravitation and density weight into the process of clustering, and proposes a gravitational Fuzzy C-Means clustering algorithm based on density weight (DWGFCM). The experimental results show that the algorithm has better global optimal solution, overcomes the shortcomings of traditional Fuzzy C-means clustering algorithm. Clustering results are obviously better than FCM algorithm.

Abstract: The outage probability of the channel state information assisted opportunistic amplify-and-forward relaying system with a maximal ratio combining receiver at the destination is investigated, and the exact outage probability expression is presented. The asymptotic equivalence of two different opportunistic relay selection criterions (maxSNR and maxmin) is proved too. Monte Carlo simulation results show that the derived expression is in excellent agreement with the outage probability of systems based on the maxSNR criterion, and also provides a good approximation to the outage probability of systems based on the maxmin criterion.