Papers by Keyword: Optimization

Abstract: Combined numerical simulations and experimentally measured data, the relationship between the initial temperature of the workpiece was described, the stamping speed, and the required forming force. Air cooling was included to determine the temperature of the part within the mold, and the required stamping force was optimized by studying the impact of the cooling time on the temperature of the part. The optimized model was verified and validated by comparing simulated data for an anti-collision beam with the experimental results of the hot-forming process. The results showed that the model provides a useful description of the hot-forming process; however, an empirical factor of 0.95 was required to achieve agreement between the simulated and experimentally measured data.

Abstract: To study structural characteristics of flying-wing vehicle, static and dynamic model of half wing span, static and dynamic model of all wing span, optimization model were established. Based on associated static test and ground resonance test data, these models were modified to implement static, dynamic and optimization analysis. Results demonstrated that structural bending and torsional deformations are mainly at outer wing surface. Torsion at inner wing is positive, while torsion at outer wing is negative. Total spar axial force along the wing span increases gradually from inner wing to outer wing and then decreases gradually after reaching the inner-outer wing interface. After axial force is transmitted to the inner wing, it is going to concentrate at the rear spar obviously. Structural bending rigidity and torsional rigidity satisfy requirements of both static force and flutter, without flutter problem of main structural mode. Viewed from the optimization size, ±45° and 0° skin at inner-outer wing turn thickens significantly. This can increase structural bending and torsional rigidity, which is good for satisfying multiple constraints comprehensively.

Abstract: Process parameters optimization is an important problem in numerical control machining, through the analysis of various factors affecting the cutting effect in cutting process, a mathematical model of cutting parameter optimization in NC machining is established and the constraint conditions are also determined in the paper. The article puts forward using genetic algorithm to realize the optimization of mathematical model, and the optimization analysis results are verified in practical processing. The experimental results show that the optimized cutting parameters can satisfy machining requests and improve the cutting efficiency.

Abstract: This paper proposes a new method to optimize the control of the heating system of a district in a way that fulfills the thermal regulations and comfort in the whole district from one side and guarantees the minimization of the energy consumption (and bill) from the other side. This new method depends on coupling buildings with different functionalities and needs. A heating plan for the coupled entities will be generated afterwards. This plan makes advantage of the difference in occupation timing of the buildings and has as constraints the thermal comfort of the occupants and the maximum available energy. This heating plan takes into consideration the building inertia to design the supply plan and maintain the constraints.

Abstract: This paper proposes the risk management strategy of the product design and development process. The process control mechanisms based on the risk management. Risk identification, assessment, migration, monitoring and reporting are applied in the product development process. Under the supervision and guidance of risk management, the risk point of product development cycle of measuring instrument is shortened about 30%, and the development costs are reduced too. The risk management improves the economic efficiency of enterprises and enhances the competitiveness of enterprises.

Abstract: Optimization of fiber orientation angle is studied to minimize the deflection of the laminated composite plates by the genetic algorithm. The objective function of optimization problem is the minimum deflection of laminated composite plates under the external load; optimization parameters are fiber orientation angle of laminated composite plates. The results for the optimal fiber orientation angle and the minimum deflection of the 4-layer plates are presented to demonstrate the validity of present method.

Abstract: Adjusting method of traditional PID controller is complicated. The controller obtained by adjusting method of traditional PID may be not optimal. Therefore, present paper utilized the genetic algorithm to optimize the PID controller parameter of roll channel of quadrotor UAV. According to the feature of lateral stability control model of quadrotor UAV, ascend time of system, steady state error, and weighted overshoot are chosen as objective function. In order to obtain the better control effect, penalty function is used to limit the oscillation of system. Simulation results show that PID controller designed by the genetic algorithm possess the excellent flexibility, adaptability and can produce the better control effect.

Abstract: Natural frequencies of simply supported laminated composite plates are calculated by the meshless global collocation method based on Gaussian radial basis function. The accuracy of meshless global radial basis function collocation method depends on the choice of shape parameter of radial basis function. In present paper, the shape parameter of Gaussian radial basis function is optimized using the genetic algorithm. Gaussian radial basis function with optimal shape parameter is utilized to analyze the natural frequencies of simply supported laminated composite plates. The present results are compared with the results of available literatures which verify the accuracy of present method.

Abstract: The purpose to optimize the ship structure is to obtain the minimum weight and the maximization of economic benefit. The way is to change the ship size, structure form, whole or partial structure layout under the condition of meeting the requirements of mechanical properties. The whole ship structure optimization model is established. Optimization is carried out by means of the Optimtoolbox in MATLAB, with the total mass of the ship as objective function, the requirements of the specification and the natural frequencies as constraint conditions. With sensitivity analysis,the thickness of bottom plate, deck, keelson, side keelson, superstructure bulkhead, hatch coaming and other components are selected as design variables. The results show that through optimization, better ship lightweight effect is obtained under the premise of guarantee hull structure strength, stiffness and dynamic characteristics. The bulk carrier structure is optimizaed.

Abstract: Optimization of material properties is performed to maximize the fundamental frequency of the laminated composite panels by means of the genetic algorithm. The global radial basis function collocation method is used to calculate the fundamental frequency of clamped laminated composite panels. In this paper, the objective function of optimization problem is the maximum fundamental frequency; optimization variables are material properties of laminated panels. The results for the optimal material properties and the maximum fundamental frequencies of the 2-layer plates are presented to verify the validity of present method.