The Experts below are selected from a list of 201951 Experts worldwide ranked by ideXlab platform

M H Ganjali - One of the best experts on this subject based on the ideXlab platform.

Z H Mazindrani - One of the best experts on this subject based on the ideXlab platform.

Eiji Ishii - One of the best experts on this subject based on the ideXlab platform.

  • moving surface mesh incorporated particle method for numerical simulation of a liquid droplet
    Journal of Computational Physics, 2020
    Co-Authors: Takuya Matsunaga, Seiichi Koshizuka, Tomoyuki Hosaka, Eiji Ishii
    Abstract:

    Abstract In this study, a new particle method for simulating the dynamics of a liquid droplet in a two-dimensional space has been developed. The proposed method incorporates a moving surface mesh to represent a deformable free-surface boundary. The domain enclosed by the surface mesh is defined as a liquid volume (droplet), and the outer region is a gas phase with constant Pressure. Fluid particles are seeded inside the liquid domain, and also, discrete nodes along the surface mesh are defined as additional computational points. The incompressible flow is solved based on the LSMPS (least squares moving particle semi-implicit) method, where all differential operators are discretized by means of consistent schemes. The stress balance equations are solved along free surfaces, where the surface tension force is directly evaluated by the geometry of the surface mesh at each surface node. As numerical tests, various Problems including a hydrostatic Pressure Problem, circular and square patch tests, droplet oscillations and static droplets suspended by solid walls have been simulated. As a result, the proposed method shows excellent agreement with the reference solutions, even under large free-surface deformations, which verifies the validity of the current developments.

Takuya Matsunaga - One of the best experts on this subject based on the ideXlab platform.

  • moving surface mesh incorporated particle method for numerical simulation of a liquid droplet
    Journal of Computational Physics, 2020
    Co-Authors: Takuya Matsunaga, Seiichi Koshizuka, Tomoyuki Hosaka, Eiji Ishii
    Abstract:

    Abstract In this study, a new particle method for simulating the dynamics of a liquid droplet in a two-dimensional space has been developed. The proposed method incorporates a moving surface mesh to represent a deformable free-surface boundary. The domain enclosed by the surface mesh is defined as a liquid volume (droplet), and the outer region is a gas phase with constant Pressure. Fluid particles are seeded inside the liquid domain, and also, discrete nodes along the surface mesh are defined as additional computational points. The incompressible flow is solved based on the LSMPS (least squares moving particle semi-implicit) method, where all differential operators are discretized by means of consistent schemes. The stress balance equations are solved along free surfaces, where the surface tension force is directly evaluated by the geometry of the surface mesh at each surface node. As numerical tests, various Problems including a hydrostatic Pressure Problem, circular and square patch tests, droplet oscillations and static droplets suspended by solid walls have been simulated. As a result, the proposed method shows excellent agreement with the reference solutions, even under large free-surface deformations, which verifies the validity of the current developments.

Xiaoli Yang - One of the best experts on this subject based on the ideXlab platform.

  • upper bound limit analysis of active earth Pressure with different fracture surface and nonlinear yield criterion
    Theoretical and Applied Fracture Mechanics, 2007
    Co-Authors: Xiaoli Yang
    Abstract:

    Abstract Conventional calculations of static and seismic active earth Pressures of soils on a retaining wall are formulated assuming the soils obeying a linear Mohr–Coulomb yield criterion. However, experimental evidences show that the strength envelopes of almost all geomaterials are nonlinear in nature over a wide range of normal stresses. In this paper, the strength envelope of the backfill behind a retaining wall is considered to follow a nonlinear yield criterion. A simple method is proposed for calculating the static and seismic active earth Pressures acting against a retaining wall using a nonlinear yield criterion. This method is based on the upper bound theorem of limit analysis. Both translational and rotational fracture surfaces are employed in the formulation for calculating active earth Pressures. Quasi-static representation of earthquake effects using a seismic coefficient concept is adopted for seismic active earth Pressure calculations. Instead of using directly the actual nonlinear yield criterion, a linear Mohr–Coulomb yield criterion, which is tangential to the nonlinear yield criterion, is used to formulate the active earth Pressure Problem as a classical nonlinear programming Problem. A nonlinear sequential quadratic programming algorithm is used to search for the maximum solution. In order to assess the validity of the proposed method, values of active earth Pressures for different values of seismic coefficients and nonlinear parameters in the yield criterion are calculated and compared with solutions obtained using an extended Rankine’s active earth Pressure theory. For the case of static active earth Pressure, the upper bound solutions using the present method with a translational fracture surface are equal to the extended Rankine’s theoretical solutions and are slightly smaller than those obtained using the present method with a rotational fracture surface. For the case of seismic active earth Pressure, numerical results obtained using the present method with a rotational fracture surface is very close to the extended Rankine’s theoretical solutions. A study is conducted to investigate the effects of the parameters in the nonlinear yield criterion on the active earth Pressures.