A new method based on the multi-wedge translation mechanism is presented to calculate the lateral force acting on the stabilizing piles. At first, there is no assumption for the shape of potential sliding surface, it ...A new method based on the multi-wedge translation mechanism is presented to calculate the lateral force acting on the stabilizing piles. At first, there is no assumption for the shape of potential sliding surface, it is just considered that the potential sliding surface is a composite of a number of straight lines. And then, the potential sliding mass is divided into a number of triangular wedges take with these straight lines as its base. The kinematic theorem of limit analysis is adopted to calculate the rate of external work and the rate of energy dissipation for each triangular wedge, respectively. Furthermore, the multivariate functions are established to calculate the lateral force acting on the stabilizing piles. The lateral force and the corresponding potential sliding surfaces can be obtained by an optimizational technique. At last, an example is taken to illustrate the method. The effect of soil strength parameters, slope angle and pile roughness on the lateral force and the corresponding potential sliding surface are analyzed.The result are compared with those obtained using other methods.展开更多
Tribological behavior of Cu-15Ni-8Sn(mass fraction, %) alloy against GCr15 ring under various loads was investigated on a ring-on-block tester in oil lubrication. The results showed that the wear rate increased slowly...Tribological behavior of Cu-15Ni-8Sn(mass fraction, %) alloy against GCr15 ring under various loads was investigated on a ring-on-block tester in oil lubrication. The results showed that the wear rate increased slowly from 1.7×10^(-7) to 9.8× 10^(-7) mm^3/mm under the load lower than 300 N, and then increased dramatically to the climax of 216×10^(-7) mm^3/mm under the load over 300 N, which indicated the transition of wear mechanism with the increase of applied load. The wear mechanism mainly was plastic deformation and abrasive wear under the load less than 300 N. As the applied load was more than 300 N, the wear mechanism of Cu-15Ni-8Sn alloy primarily was delamination wear. Besides, the transition can also be confirmed from the different morphologies of worn surface, subsurface and wear debris. It is distinctly indicated that the appearance of flaky debris at the applied load over 300 N may be a critical point for the change of wear mechanism.展开更多
Firstly,the common design principles for diversion tunnel plug are generalized,and two kinds of numerical analysis methods are discussed.Then the strength reduction FEM is introduced in numerical model analysis and th...Firstly,the common design principles for diversion tunnel plug are generalized,and two kinds of numerical analysis methods are discussed.Then the strength reduction FEM is introduced in numerical model analysis and the design steps of the plug's length are illustrated.During the progress to determine the plug's length,the equivalent plastic strain on the potential slip surface is assumed as the flag to tell the failure against sliding,and the plug stability is overall estimated from the plastic zone range and connectivity.展开更多
In this paper, steady incompressible micropolar fluid flow through a non-uniform channel with multiple stenoses is considered. Assuming the stenoses to be mild and using the slip boundary condition, the equations gove...In this paper, steady incompressible micropolar fluid flow through a non-uniform channel with multiple stenoses is considered. Assuming the stenoses to be mild and using the slip boundary condition, the equations governing the flow of the proposed model are solved, and closed-form expressions for the flow characteristics （resistance to flow and wall shear stress） are derived. The effects of different parameters on these flow characteristics are analyzed. It is observed that both the resistance to the flow and the wall shear stress increase with the heights of the stenoses and the slip parameter; but decrease with the Darcy number, b^rthermore, the effects of the wall exponent parameter, the cross-viscosity coefficient and the micropolar parameter on the flow characteristics are discussed.展开更多
基金Projects(SKLGP2012K024,SKLGP2013K012)supported by the Opening Fund of State Key Laboratory of Geohazard Prevention and Ceoenvironment Protection,ChinaProject(2011BAK12B03)supported by the National Technology Project,ChinaProject(41401004)supported by the National Natural Science Foundation of China
文摘A new method based on the multi-wedge translation mechanism is presented to calculate the lateral force acting on the stabilizing piles. At first, there is no assumption for the shape of potential sliding surface, it is just considered that the potential sliding surface is a composite of a number of straight lines. And then, the potential sliding mass is divided into a number of triangular wedges take with these straight lines as its base. The kinematic theorem of limit analysis is adopted to calculate the rate of external work and the rate of energy dissipation for each triangular wedge, respectively. Furthermore, the multivariate functions are established to calculate the lateral force acting on the stabilizing piles. The lateral force and the corresponding potential sliding surfaces can be obtained by an optimizational technique. At last, an example is taken to illustrate the method. The effect of soil strength parameters, slope angle and pile roughness on the lateral force and the corresponding potential sliding surface are analyzed.The result are compared with those obtained using other methods.
基金Project(2016YFB0301402)supported by the National Key Research and Development Program of ChinaProject(CSU20151024)supported by the Innovation-driven Plan in Central South University,China
文摘Tribological behavior of Cu-15Ni-8Sn(mass fraction, %) alloy against GCr15 ring under various loads was investigated on a ring-on-block tester in oil lubrication. The results showed that the wear rate increased slowly from 1.7×10^(-7) to 9.8× 10^(-7) mm^3/mm under the load lower than 300 N, and then increased dramatically to the climax of 216×10^(-7) mm^3/mm under the load over 300 N, which indicated the transition of wear mechanism with the increase of applied load. The wear mechanism mainly was plastic deformation and abrasive wear under the load less than 300 N. As the applied load was more than 300 N, the wear mechanism of Cu-15Ni-8Sn alloy primarily was delamination wear. Besides, the transition can also be confirmed from the different morphologies of worn surface, subsurface and wear debris. It is distinctly indicated that the appearance of flaky debris at the applied load over 300 N may be a critical point for the change of wear mechanism.
基金National Natural Science Foundation of China(No.50809051)
文摘Firstly,the common design principles for diversion tunnel plug are generalized,and two kinds of numerical analysis methods are discussed.Then the strength reduction FEM is introduced in numerical model analysis and the design steps of the plug's length are illustrated.During the progress to determine the plug's length,the equivalent plastic strain on the potential slip surface is assumed as the flag to tell the failure against sliding,and the plug stability is overall estimated from the plastic zone range and connectivity.
文摘In this paper, steady incompressible micropolar fluid flow through a non-uniform channel with multiple stenoses is considered. Assuming the stenoses to be mild and using the slip boundary condition, the equations governing the flow of the proposed model are solved, and closed-form expressions for the flow characteristics （resistance to flow and wall shear stress） are derived. The effects of different parameters on these flow characteristics are analyzed. It is observed that both the resistance to the flow and the wall shear stress increase with the heights of the stenoses and the slip parameter; but decrease with the Darcy number, b^rthermore, the effects of the wall exponent parameter, the cross-viscosity coefficient and the micropolar parameter on the flow characteristics are discussed.
