Applied Mechanics and Materials Vols. 556-562

Abstract: A new reliability-based topology optimization method for compliant mechanisms with geometrical nonlinearity is presented. The aim of this paper is to integrate reliability and geometrical nonlinear analysis into the topology optimization problems. Firstly, geometrical nonlinear response analysis method of the compliant mechanisms is developed based on the Total-Lagrange finite element formulation, the incremental scheme and the Newton-Raphson iteration method. Secondly, a multi-objective topology optimal model of compliant mechanisms considering the uncertainties of the applied loads and the geometry descriptions is established. The objective function is defined by minimum the compliance and maximum the geometric advantage to meet both the stiffness and the flexibility requirements, and the reliabilities of the compliant mechanisms are evaluated by using the first order reliability method. Thirdly, the computation of the sensitivities is developed with the adjoint method and the optimization problem is solved by using the Method of Moving Asymptotes. Finally, through numerical calculations, reliability-based topology designs with geometric nonlinearity of a typical compliant micro-gripper and a multi-input and multi-output compliant sage are obtained. The importance of considering uncertainties and geometric nonlinearity is then demonstrated by comparing the results obtained by the proposed method with deterministic optimal designs, which shows that the reliability-based topology optimization yields mechanisms that are more reliable than those produced by deterministic topology optimization.

Abstract: The combat environment of Unmanned Aerial Vehicles (UAVs) is filled with uncertain factors, which is complex and dynamic. This paper is devoted to the UAV mission planning problem under uncertain environment with three optimization objectives, such as flight time, fuel usage and threat imposed by enemy. Based on the uncertainty theory and multiobjective programming method, the UAV uncertain multiobjective mission plaaning model is built and solved.

Abstract: In order to improve the machining efficiency of the CNC laser drilling, this paper presents the path optimized method based on an improved ant colony algorithm of the k-means clustering approach. The mathematical model of the path optimization is constructed, and the path optimized method based on the improved clustering ant colony algorithm is designed and actualized. The optimized path method for CNC laser drilling based on the improved clustering ant colony algorithm is tested, and the simulative and experimental result have shown that the proposed method is better performance, and the machining efficiency is greatly improved.

Abstract: For study the damage effect of discrete rod warhead to supersonic missile engine cabin, the rods attacking the supersonic missile engine cabin were simulated by using ANSYS / LS-DYNA software. Acquired the influence rules that the postures of the rods and the number of the rods attacking the target to damage the supersonic missile engine cabin. The results show: the postures of the rods have great influences to damage the supersonic missile engine cabin; When the rods are straight circular permutation, the rods have the best damage effect to engine cabin; the smaller of the angle between the rods vertical axis and the engine cabin vertical axis, the damage ability is the strongest. Really not the more number of the rods attack into the supersonic missile engine cabin, the damage effect is the better; contrasted the conditions with the same rotation angles, the damage effect to engine cabin, the conditions of 4 rods attacking into the engine cabin are better than the conditions of 5 rods attacking into the engine cabin.

Abstract: Under the background of a great boom in contemporary culture, network culture has rapidly developed into a form of manifestation. Groups of college students as the most active use of network source also makes the network culture gradually permeate the campus, which has made a great influence on moral cognition of college students. Based on the background of current large network culture, this paper firstly analyzes the situation of network utilization by college students. Then we find that the construction of early warning model of moral cognition for college students is imminent. And we construct the early warning model of moral cognition by using the algorithm of sine function model. In order to verify the practicability of the model, we use the interactive multi-model simulation analysis, and the results indicate that the model has a strong practicality, and has a very good controllability, which has a positive role in promoting the education of moral cognition for college students.

Abstract: In view of fuel consumption problem of the formation establishment, starting from the fly around equation, using double-impulse, the optimization is simulated based on the Niche Genetic Algorithm (NGA). The simulation result shows that the NGA is a good way to solve the fuel consumption optimization problem of formation establishment, and the fuel consumption when the phase determined is greater than the fuel consumption when the phase not determined.

Abstract: Due to the presence of starting pressure of low permeability reservoir, so researching on starting pressure gradient of low permeability reservoir is necessary. while starting pressure gradient is relevant to permeability and porosity, it can be obtained through laboratory experiments¡¢well testing interpretation method¡¢theory derivation combined with practical application method . The result of a large number of laboratory experiments shows: starting pressure is related to permeability .The greater the permeability is, the smaller the starting pressure is. They both present the similar hyperbolic relationship; the greater the viscosity of the oil is, the greater the starting pressure is. In this paper, we get the starting pressure gradient formula through the method of theory derivation combined with practical application, meanwhile we put forward the relationship between starting pressure gradient and permeability, porosity¡¢viscosity .

Abstract: By using milk production data of Guangxi statistical yearbook from 2001 to 2010, based on the Grey theory and Grey prediction models, which are GM(1,1), have been adopted to predict the milk throughput of Guangxi in this paper. So we establish the GM(1,1) prediction model and predict the milk production of Guangxi from 2011 to 2020. The results show that the Grey theory and Grey prediction models have good simulation and feasibility. At the same time, with the combination of livestock products market demand, we provide livestock enterprises and farmers with some appropriate recommendations.

Abstract: This paper introduces an improved implementation of the anisotropic-medium perfectly matched layer for efficient Laguerre-based finite-difference time-domain method. Compared with the original implementation, the new formulations do not involve any nonphysical intermediate variables, while being more concise. The numerical example shows that the proposed implementation is valid.

Abstract: Global Positioning System (GPS) becomes one of the key technologies in precise navigation and position area. Interference Suppression technology of GPS plays an essential role in the accuracy of GPS positioning. In this paper, we proposed a more efficient scheme based on Gram-Schmidt algorithm with the training sequence, which is named the GSCE algorithm (the Gram-Schmidt Channel estimation algorithm). Compared with some other existing methods, the algorithm improves the positioning precision of the GPS by estimating channel parameters.