We develop a adaptive evolutionary algorithm based on neighborhood searching. Firstly, class the individuals by the fitness number to realize the division of population.
In this paper, a nonlocal theory of fracture for brittle materials has beenproposed. It contains the nonlocal elastic stress fields of mode-I, II, III Griffith cracks, the asymptotic forms of the stress fields at the neighborhood of the crack tips, and the maximum tensile stress criterion of brittle fracture.
Major results of recent researches on the numerical simulation of wave motion generated by a wave source (or a scatterer) in its neighborhood are reviewed with emphasis on the progress in studies on the artificial boundary condition——the key problem in the numerical simulation.
A time_varying feedback control law is established on the base of local linearization. The Liapunov direct method is applied to estimate the neighborhood in which the control law can be effectively used. Numerical examples are presented to demonstrate the applications of the control law to solve the problem of stabilizing unstable periodic orbits and the problem of tracking an arbitrarily given periodic orbit.
The fourth-order explicit upwind-biased compact difference schemes are used to overcome the difficulty of not adapting to boundary neighborhood for the general fourth-order central difference schemes.
Our country is a nation with high activity and high-frequency of earthquakes. Moreover almost all of oil fields located in the seismic zone and neighborhood.
An analysis of the relative importance of the coefficients shows that the rotation effect cannot be neglected near the pore opening or near the Wall, and that the lateral force effect must be taken into account in the neighborhood of the edge of the pore opening.
Let the ratio of the lengths of the sides of the cross-section be 1:26. By using Poin-care-Keller's shooting method and introducing rescaling functions, we investigate the case in which 6 is in a neighborhood of δ0= 1. The secondary bifurcations of the equilibrium state of the bar are found whenδ≠1; we also give the asymptotic unfoldings of the primary branchesand secondary branches, and make analysis on the stability of each branch.
On the basis of comprehensive tests for fatigue crack growth rate and photoelastic study of CT specimen made of polycarbonate,it is found that residual stress field is formed and intensified in the neighborhood of crack tip along with the growth of fatigue crack.
Like the truncations of the Taylor expansion, the truncations of a chromatic expansion at t = t0 of an analytic function f(t) approximate f(t) locally, in a neighborhood of t0.
It is available for the case that the sign of f(x) changes frequently or the derivative f'(x) does not exist in the neighborhood of the root, while the Newton method is hard to work.
One allows the appearance of eight limit cycles in the neighborhood of infinity, which is the first example that a polynomial differential system bifurcates eight limit cycles at infinity.
For any study of a suspension entering a pore, the knowledge of the force and moment exerted on a solute particle in an arbitrary position outside the pore is essential. This paper for the first time presents approximate analytical expressions (in closed form) of all the twelve force and moment coefficients for a sphere outside a circular orifice, on the basis of a number of discrete data computed by Yan et at. (1987). These coefficients are then applied to calculate the trajectory and angular velocity of a...
Based on the equilibrium equation of an elastic curved bar in [1] , the post-buckling behavior of a slender bar with rectangular cross-section under axial compression is studied. Let the ratio of the lengths of the sides of the cross-section be 1:26. By using Poin-care-Keller's shooting method and introducing rescaling functions, we investigate the case in which 6 is in a neighborhood of δ0= 1. The secondary bifurcations of the equilibrium state of the bar are found whenδ≠1; we also give the asymptoti...
On the basis of comprehensive tests for fatigue crack growth rate and photoelastic study of CT specimen made of polycarbonate,it is found that residual stress field is formed and intensified in the neighborhood of crack tip along with the growth of fatigue crack. Thus the existence of close effect in the neighborhood of crack tip is revealed.This kind of residual stress and close effect will reduce the stress intensity factor.Therefore the theoretical value △K in the course of fatigue crack grow...