Song Xiang

Fiber Orientation Angles Optimization for Maximum Fundamental Frequency of Laminated Composite Plates by the Genetic Algorithm and Meshless Method

Fiber orientation angles optimization is carried out for maximum fundamental frequency of clamped laminated composite plates using the genetic algorithm. The meshless method is utilized to calculate the fundamental frequency of clamped laminated composite plates. In the present paper, the maximum fundamental frequency is an objective function; design variables are a set of fiber orientation angles in the layers. The examples of square laminated plates are considered. The results for the optimal fiber orientation angles and the maximum fundamental frequencies of the 2-layer plates are presented.

Longitudinal Nonlinear PID Controller Parameter Optimization of Autopilot Using Genetic Algorithm

This paper performed the longitudinal nonlinear PID Controller parameter optimization of general aircraft autopilot based on the longitudinal channel model and genetic algorithm. Proportion, integration and differential gain of nonlinear PID Controller is nonlinear function of controlling error. The objection function involves time integration of error’s absolute value, output of controller and system overshoot. The longitudinal controlling rate optimization of general aircraft autopilot is realized by minimizing the objection function value. Simulation results show that controller designed by the present method is better than traditional PID controller.

Natural Frequencies of Functionally Graded Beams by the Various Shear Deformation Theories

Various higher order shear deformation theories of Levinson, Touratier, Karama are utilized to calculate the natural frequencies of functionally graded beams. The governing differential equations are solved by an analytical method. The present results are compared with the results of Aydogdu which demonstrate the accuracy of various theories.

Fiber Orientation Angle Optimization for Minimum Stress of Laminated Composite Plates

The genetic algorithm is used to minimize the stress of the laminated composite plates by optimizing the fiber orientation angle. The objective function of optimization problem is the minimum stress in center of laminated composite plates under the external load; optimization variables are fiber orientation angle. The results for the optimal fiber orientation angle and the minimum stress of the 2-layer plates and 3-layer plates are presented.

Natural Frequency of Laminated Composite Plates Using a Sinusoidal Theory

Sinusoidal shear deformation theory is presented to analyze the natural frequencies of simply supported laminated composite plates. The governing differential equations based on sinusoidal theory are solved by a Navier-type analytical method. The present results are compared with the available published results which verify the accuracy of sinusoidal theory.

Tailoring the Fundamental Frequency of Laminated Composite Panels Using Material Properties

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.

Shape Parameter Optimization of Gaussian Radial Basis Function Using Genetic Algorithm for Natural Frequencies of Laminated Composite Plates

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.

Layer Thickness Optimization of Laminated Composite Plates to Maximize the First-Order Natural Frequency

Layer thickness optimization is performed to maximize the first-order natural frequency of clamped laminated composite plates using the genetic algorithm and meshless global radial basis function collocation method. The objective function of optimization problem is the maximum first-order natural frequency; optimization variables are layer thickness. The optimal layer thickness and the maximum first-order natural frequency of the 2-layer plates are presented to demonstrate the accuracy of present method.

A Method Combined with the Genetic Algorithm for Design of High Efficiency Propeller

In this paper, a design method combined with the genetic algorithm is proposed to design the propeller of general aviation aircraft. The inputs of this method are the cruise speed, rotational speed, propeller diameter, number of blade, thrust, Reynolds and Mach numbers. The chord and pitch-angle angle distributions along the blade are the outputs of this method. The propeller of a kind of Li-ion battery powered aircraft is designed by the present method.

Analysis of Laminated Composite Plates by Local Inverse Multiquadrics Collocation Method

In present paper, deflection and stress of laminated composite plates are analyzed by a meshless local collocation method based on inverse multiquadrics radial basis function. This method approximates the governing equations based on first-order shear deformation theory using the nodes in the support domain of any data center. Transverse displacement, normal stresses, and shear stresses of the simply supported laminated composite plates under sinusoidal load are computed by the present method. The convergence characteristics are studied by several numerical examples. The present results are compared with available published results which demonstrate the accuracy and efficiency of present method.