Applied Mechanics and Materials Vols. 444-445

Abstract: The purpose of this paper is to simulate flight path of Boeing-747 for longitudinal motion at selected flight conditions using 6 DoF (Degrees of freedom) nonlinear equations with MATLAB and SIMULINK. The equations are solved to compute the flight path within 100 seconds of Boeing 747 at three flight conditions, for cruise flight with different Mach numbers at same altitudes, and then Mach number at high altitude with MATLAB programming (ode45). Simulation results for different conditions are presented and analyzed.

Abstract: In this paper, the generator included typical automatic voltage regulation (AVR) and power system stabilizer (PSS) SCR excitation system is taken as the research object, The Hamiltonian energy function and its general Hamilton control model are analyzed, on the basis of the five order Hamilton system model, positive definite conditions of the damping matrix R(x) was derived, and the system dissipation characteristics was analyzed. Using the Hamilton energy design method, the control strategy of system was designed, under the above control, the system is finite-gain L₂ stable when external disturbance occurs.

Abstract: A static aeroelastic responses analysis method based on mapping external nonlinear aerodynamic forces onto 3D body surface panel elements is proposed. The external nonlinear aerodynamic force data can be obtained by Euler solver, Navier-Stokes solver and wind tunnel tests. In this paper, the method is applied to obtain static aeroelastic responses of a flexible aircraft, and the emphasis is placed on the change of aerodynamic coefficient, aerodynamic pressure distribution and flight load. The results are compared with static aeroelastic responses calculated by high-order panel method. It is concluded that the method presented in this study is feasible, credible and efficient, and can provide an assessment of static aeroelastic response characteristics for the detailed stage of aircraft design.

Abstract: In this paper we will show that two different specific chaos maps are topological conjugate, and homeomorphism functions are not absolutely continuous on any interval in .

Abstract: According to the issue of comprehensive transportation structure the authors establish the logistic differential equation model to describe the competition process of railway transport and highway transport. By the stability analysis of the model the evolution trends between railway transport and highway transport are obtained. Using MATLAB software the model simulates the evolution trends under the different parameters conditions.

Abstract: To enhance the efficiency for the shape optimization of complex nonlinear structure, based on the FE analysis combined with the sensitivity analysis, the gradient-based Kriging (GBK) method is applied. A new criterion to determine the likely best spatial correlation parameter in GBK based on Latin Hypercube Design (LHD) presented by authors is also applied. A more practical example for the shape optimization of automotive tire is presented to show the applicability of the GBK method.

Abstract: Lorenz system families contain Lorenz system, Chen system and Lu system, their accurate analytical solutions are not yet obtained now. The segmenting recursion method was put forward in this paper, the equations of Lorenz system families were reasonably linearized within small segment, the recursion formulas were obtained by solving the approximate analytical solutions within small segment, and all numerical solutions were got by the recursion formulas. The chaotic motion of Lorenz system families were numerically simulated by means of the segmenting recursion method, the simulation results were compared with Runge-Kutta method. The comparative results show that the segmenting recursion method is very effective to numerically simulate Lorenz system families, not only method is simple, programming is easy, but result is accurate. this method is a universal new method to numerically simulate similar system.

Abstract: The subharmonic and chaotic behavior of a two end-fixed fluid conveying pipe whose base is subjected to a harmonic excitation are investigated. Melnikov method is applied for the system, and Melnikov criterions for subharmonic and homoclinic bifurcations are obtained analytically. The numerical simulations (including bifurcation diagrams, maximal Lyapunov exponents, phase portraits and Poincare map) confirm the analytical predictions and exhibit the complicated dynamical behaviors.

Abstract: The existence and stability of subharmonic oscillations in a two end-fixed fluid conveying pipe whose base is subjected to a harmonic excitation are investigated. A Galerkin approach is utilized to reduce the equation of motion to a second order nonlinear differential equation. The conditions for the existence of subharmonic oscillations are given by using Melnikov method. The stability of subharmonic oscillations is discussed in detail by using action-angle variable and averaging method. It is shown that the velocity of fluid plays an important role in the stability of subharmonic oscillations.

Abstract: The cusp catastrophic model based on catastrophe theory is presented to analyze the development pattern evolution of comprehensive transportation system (CTS for short). By establishing cusp catastastrophe model of development pattern we obtain that the construction of comprehensive transportation system should include two parts, the first part is the stock optimization and the second part is the increment construction. With the increment construction as the turning point, promoting the fast optimization of the stock should be the basic principles of the construction and development of CTS.