Papers by Author: Qing Li

Paper TitlePage

Authors: Xiao Chuan Li, Qing Li
Abstract: The theory of Hamiltonian system is introduced for the problems of laminated transversely isotropic magnetoelectroelastic plates. The partial differential equations of the magnetoelectroelastic solids are derived corresponding to the Lagrange density function and Legendre’s transformation. These equations are a set of the first-order Hamiltonian equations and expressed with displacements, electric potential and magnetic potential, as well as their dual variables--lengthways stress, electric displacement and magnetic induction in the symplectic geometry space. To obtain the solutions of the equations, the schemes of separation of variables and expansion of eigenvector of Hamiltonian operator matrix in the polar direction are implemented. The homogenous solutions of the equations consist of zero eigen-solutions and nonzero eigen-solutions. All the eigen-solutions of zero eigenvalue are obtained in the symmetric deformation. These solutions give the classical Saint-Venant’s solutions because the Hamiltonian matrix is symplectic. The method is rational, analytical method and does not require any trial functions.
2425
Authors: Zhe Zhang, Yan Feng Feng, Qing Li, Shu Juan Zheng
Abstract: Based on the heterogeneity of rock, by using the RFPA2D, influene of the horizontal in-situ stresses on the distributions of plastic zones is discussed. Among the current problems that rock or civil engineers face, perhaps there is none as challenging as the characterization of fluid flow though fracturing rocks, especially when they are highly stressed. In mining and civil engineering projects, the re-distribution of the stress field during the excavation of tunnels and underground chambers lead to the formation of new fractures. These damages may cause dramatic changes in the permeability of the rock masses. As a result, the rate of water flowing into the tunnels and chambers will increase.
3377
Authors: Zhe Zhang, Yan Feng Feng, Qing Li, Qing Lei Yu
Abstract: Based on the heterogeneity of rock, by using the RFPA2D, influene of the horizontal in-situ stresses on the distributions of plastic zones is discussed. The deformation and nonlinear gradual failure characteristics of circular roadway in deep rock mass as well as the displacement and the stress variation of the key position in the periphery of the roadway were analyzed, When λ>1, the plastic area was large-scale, but deflection more little , when λ<1, the plastic area was little-scale, but deflection increase. The study indicates that the stress concentration occurs in the periphery of the roadway after evacuation and plastic deformation zone engenders under the persisting stress of the surrounding rock, then the cracks appears and expands continuously, the broken rock zone appears at last and the intensity of the stress concentration decreases as well as the stress field shifts beyond.
1700
Showing 1 to 3 of 3 Paper Titles