The Experts below are selected from a list of 6771 Experts worldwide ranked by ideXlab platform
Y Zhang - One of the best experts on this subject based on the ideXlab platform.
-
Explicit Integration Scheme of a subloading surface plasticity model for unsaturated soils
Japanese Geotechnical Society Special Publication, 2017Co-Authors: Y Zhang, Annan ZhouAbstract:An adaptive substepping Explicit Integration Scheme is proposed for a subloading surface plasticity (SSP) model for unsaturated soils. The SSP model is referred to as the modified σ Θ model, the constitutive laws of which are established in the space of Bishop's effective stress ( σ ) and effective degree of saturation (Θ ). The modified σ Θ model includes a convex subloading surface in the p-q plane and a nonconvex subloading surface in the p- Θ plane. The convex/nonconvex subloading surface in the model may cause problems of incorrect loading-unloading decisions during the stress update. A Double Cosine loading-unloading decision method (DC method) is revised and embedded into the Explicit Integration Scheme for the modified σ Θ model. The local error of the effective degree of saturation ( Θ ) is introduced in the error control for each substep. The performance of the DC method for the modified σ Θ model is discussed. The importance of involving the effective saturation ( Θ ) in the error control is also demonstrated via numerical examples.
-
Explicit Integration of a porosity‐dependent hydro‐mechanical model for unsaturated soils
International Journal for Numerical and Analytical Methods in Geomechanics, 2016Co-Authors: Y Zhang, Annan ZhouAbstract:An adaptive substepping Explicit Integration Scheme is developed for a porosity-dependent hydro-mechanical model for unsaturated soils. The model is referred to as the modified sigma- model in this paper, which features the employment of the subloading surface plasticity and the stress-saturation approach. On numerical aspects, convex/nonconvex subloading surfaces in the sigma- space may result in incorrect loading-unloading decisions during the Integration. A new loading-unloading decision method is developed here to solve the problem and then embedded into the Explicit Integration Scheme for the modified sigma- model. In addition, to enhance the accuracy of the Explicit Integration, local errors from both hydraulic and mechanical components are included in the error control for each substep. A drift correction method is also developed to ensure the state point lies on the subloading surface in the sigma- space within a set error level. The performance of the loading-unloading decision method for the modified sigma- model is discussed through comparing it with the conventional loading-unloading decision method. The importance of involving the hydraulic component in the error control is also demonstrated. The accuracy and efficiency of the proposed adaptive substepping Explicit Integration Scheme for the modified p- model are also studied via several numerical examples.
-
Explicit Integration Scheme for a non-isothermal elastoplastic model with convex and nonconvex subloading surfaces
Computational Mechanics, 2015Co-Authors: Annan Zhou, Y ZhangAbstract:An adaptive substepping Explicit Integration Scheme with a novel loading-unloading decision method is developed here for the non-isothermal unified hardening (UH) model. The non-isothermal UH model includes a convex subloading surface in the $$p$$p---$$q$$q plane and a nonconvex subloading surface in the $$p$$p---$$T$$T plane. Because of the convex/nonconvex subloading surfaces, the conventional loading-unloading decision method used in stress Integration Schemes may lead to incorrect elasticity/elastoplasticity judgements. In addition, the conventional loading-unloading decision method is unable to determine the division point that separates the elastic segment from the elastoplastic segment. A simple but robust method, the double cosine (DC) method, is proposed in this paper to solve loading-unloading decision problems. The proposed DC method is then embedded into an adaptive substepping Explicit Integration Scheme to implement the non-isothermal UH model. The accuracy and efficiency of the DC method are discussed by comparing the method with the conventional loading-unloading decision method (the CV method) and the root-finding loading-unloading decision method (the RF method). The performance of the proposed Scheme with the DC method is also discussed.
Annan Zhou - One of the best experts on this subject based on the ideXlab platform.
-
Explicit Integration Scheme of a subloading surface plasticity model for unsaturated soils
Japanese Geotechnical Society Special Publication, 2017Co-Authors: Y Zhang, Annan ZhouAbstract:An adaptive substepping Explicit Integration Scheme is proposed for a subloading surface plasticity (SSP) model for unsaturated soils. The SSP model is referred to as the modified σ Θ model, the constitutive laws of which are established in the space of Bishop's effective stress ( σ ) and effective degree of saturation (Θ ). The modified σ Θ model includes a convex subloading surface in the p-q plane and a nonconvex subloading surface in the p- Θ plane. The convex/nonconvex subloading surface in the model may cause problems of incorrect loading-unloading decisions during the stress update. A Double Cosine loading-unloading decision method (DC method) is revised and embedded into the Explicit Integration Scheme for the modified σ Θ model. The local error of the effective degree of saturation ( Θ ) is introduced in the error control for each substep. The performance of the DC method for the modified σ Θ model is discussed. The importance of involving the effective saturation ( Θ ) in the error control is also demonstrated via numerical examples.
-
Explicit Integration of a porosity‐dependent hydro‐mechanical model for unsaturated soils
International Journal for Numerical and Analytical Methods in Geomechanics, 2016Co-Authors: Y Zhang, Annan ZhouAbstract:An adaptive substepping Explicit Integration Scheme is developed for a porosity-dependent hydro-mechanical model for unsaturated soils. The model is referred to as the modified sigma- model in this paper, which features the employment of the subloading surface plasticity and the stress-saturation approach. On numerical aspects, convex/nonconvex subloading surfaces in the sigma- space may result in incorrect loading-unloading decisions during the Integration. A new loading-unloading decision method is developed here to solve the problem and then embedded into the Explicit Integration Scheme for the modified sigma- model. In addition, to enhance the accuracy of the Explicit Integration, local errors from both hydraulic and mechanical components are included in the error control for each substep. A drift correction method is also developed to ensure the state point lies on the subloading surface in the sigma- space within a set error level. The performance of the loading-unloading decision method for the modified sigma- model is discussed through comparing it with the conventional loading-unloading decision method. The importance of involving the hydraulic component in the error control is also demonstrated. The accuracy and efficiency of the proposed adaptive substepping Explicit Integration Scheme for the modified p- model are also studied via several numerical examples.
-
Explicit Integration Scheme for a non-isothermal elastoplastic model with convex and nonconvex subloading surfaces
Computational Mechanics, 2015Co-Authors: Annan Zhou, Y ZhangAbstract:An adaptive substepping Explicit Integration Scheme with a novel loading-unloading decision method is developed here for the non-isothermal unified hardening (UH) model. The non-isothermal UH model includes a convex subloading surface in the $$p$$p---$$q$$q plane and a nonconvex subloading surface in the $$p$$p---$$T$$T plane. Because of the convex/nonconvex subloading surfaces, the conventional loading-unloading decision method used in stress Integration Schemes may lead to incorrect elasticity/elastoplasticity judgements. In addition, the conventional loading-unloading decision method is unable to determine the division point that separates the elastic segment from the elastoplastic segment. A simple but robust method, the double cosine (DC) method, is proposed in this paper to solve loading-unloading decision problems. The proposed DC method is then embedded into an adaptive substepping Explicit Integration Scheme to implement the non-isothermal UH model. The accuracy and efficiency of the DC method are discussed by comparing the method with the conventional loading-unloading decision method (the CV method) and the root-finding loading-unloading decision method (the RF method). The performance of the proposed Scheme with the DC method is also discussed.
T. Davies - One of the best experts on this subject based on the ideXlab platform.
-
a conservative split Explicit Integration Scheme with fourth order horizontal advection
Quarterly Journal of the Royal Meteorological Society, 1991Co-Authors: M. J. P. Cullen, T. DaviesAbstract:A split-Explicit finite difference Scheme is developed which combines the accuracy and economy required for numerical weather prediction with the conservation properties required for climate-change experiments. Results are presented to demonstrate the Scheme working in practice.
-
A conservative split‐Explicit Integration Scheme with fourth‐order horizontal advection
Quarterly Journal of the Royal Meteorological Society, 1991Co-Authors: M. J. P. Cullen, T. DaviesAbstract:A split-Explicit finite difference Scheme is developed which combines the accuracy and economy required for numerical weather prediction with the conservation properties required for climate-change experiments. Results are presented to demonstrate the Scheme working in practice.
M. J. P. Cullen - One of the best experts on this subject based on the ideXlab platform.
-
a conservative split Explicit Integration Scheme with fourth order horizontal advection
Quarterly Journal of the Royal Meteorological Society, 1991Co-Authors: M. J. P. Cullen, T. DaviesAbstract:A split-Explicit finite difference Scheme is developed which combines the accuracy and economy required for numerical weather prediction with the conservation properties required for climate-change experiments. Results are presented to demonstrate the Scheme working in practice.
-
A conservative split‐Explicit Integration Scheme with fourth‐order horizontal advection
Quarterly Journal of the Royal Meteorological Society, 1991Co-Authors: M. J. P. Cullen, T. DaviesAbstract:A split-Explicit finite difference Scheme is developed which combines the accuracy and economy required for numerical weather prediction with the conservation properties required for climate-change experiments. Results are presented to demonstrate the Scheme working in practice.
Sia Nemat-nasser - One of the best experts on this subject based on the ideXlab platform.
-
An Explicit Integration Scheme for finite-deformation plasticity in finite-element methods
Finite Elements in Analysis and Design, 1993Co-Authors: Yeou-fong Li, Sia Nemat-nasserAbstract:Abstract A new Explicit Integration Scheme is presented for finite-deformation (large strains and rotations) computational plasticity. The results are accurate and stable.
