Subloading Surface Model Research Articles

Loading criterion in return-mapping for subloading surface model

Loading criterion in return-mapping for subloading surface model

完全陰的応力更新による拡張下負荷面モデルに基づく弾塑性解析

完全陰的応力更新による拡張下負荷面モデルに基づく弾塑性解析

108 下負荷面モデルによる繰返し負荷挙動の高精度予測(GS1,3 材料力学(1),研究討論セッション)

108 下負荷面モデルによる繰返し負荷挙動の高精度予測(GS1,3 材料力学(1),研究討論セッション)

損傷現象を考慮した拡張下負荷面モデルによる弾塑性解析

損傷現象を考慮した拡張下負荷面モデルによる弾塑性解析

Exact Formulation of Subloading Surface Model: Unified Constitutive Law for Irreversible Mechanical Phenomena in Solids

The subloading surface model is endowed with the intrinsic far-reaching ability to describe the wide classes of irreversible mechanical behavior, e.g. the monotonic and the cyclic loading behavior of elastoplastic and viscoplastic materials, the friction behavior and the crystal plastic behavior as has been examined in the former paper (Hashiguchi in Arch Comput Methods Eng 20:361–417, 2013). However, the past formulations of the subloading surface model have contained several inexact equations, which have been modified repeatedly since the concept of the subloading surface was proposed in 1977 (Hashiguchi and Ueno 1977). The exact formulation is presented first in this article for the hypoelastic-based plasticity, which enjoys the distinguished superiority in the both aspects of the description of material behavior in high accuracy and of the numerical calculation in high efficiency. It is further provided for all the four basic frameworks, i.e. the infinitesimal hypoelastic-based plasticity, the infinitesimal hyperelastic-based plasticity, the hypoelastic-based plasticity and the multiplicative hyperelastic-based plasticity for finite strain. Further, the subloading-crystal plasticity model is formulated modifying the former one (Hashiguchi 2013) by incorporating the decomposition of the crystalline shear strain rate into the elastic and the plastic parts. This would be the guidebook to the subloading surface model and also the memorial monograph for the historical development of the subloading surface model.

G0300603 等方硬化鈍化を導入した拡張下負荷面モデルに基づくリターンマッピングによる弾塑性解析

The subloading surface model has been formulated and applied to the prediction of cyclic loading behavior of metals. Furthermore, the return-mapping for the subloading surface model has been formulated and used in order to obtain high calculation efficiency in the whole loading state. In this article, the return-mapping in cutting-plane projection is extended so as to describe the cyclic stagnation of isotropic hardening to make the accurate prediction of the cyclic loading behavior. Then, the validity and efficiency of this algorithm for the description of cyclic loading behavior of ductile cast iron are verified by comparison with the test data.

G0300701 拡張下負荷面モデルに基づくリターンマッピングを用いた完全陰解法の定式化および弾塑性解析への適用

The subloading surface model has been formulated and applied to the prediction of cyclic loading behavior of metals. In this article, the return-mapping in the fully implicit algorithm based on the extended subloading surface model is formulated aiming at obtaining accurate solutions in a high efficiency in the whole loading state. It is incorporated into the implicit finite element program Abaqus through the User-subroutine UMAT. Simulation result by the fully implicit algorithm is compared to the forward Euler algorithm about the accuracy and the convergence property under the cyclic loading.

GS0304-358 拡張下負荷面モデルに基づくリターンマッピングを用いた応力更新法と弾塑性解析への適用

GS0304-358 拡張下負荷面モデルに基づくリターンマッピングを用いた応力更新法と弾塑性解析への適用

Cyclically Triggered Instability and Yield-vertex Effect on a Welded Plate Investigated by means of the Extended Subloading Surface Model with Tangential Plasticity

Cyclically Triggered Instability and Yield-vertex Effect on a Welded Plate Investigated by means of the Extended Subloading Surface Model with Tangential Plasticity

Extension of subloading surface model for accurate prediction of elastoplastic deformation behavior of metals with cyclic softening

The subloading surface model has been formulated and applied to the prediction of cyclic loading behavior of metals. However, the existing formulation of this model is limited to metals exhibiting only the cyclic hardening. In the present paper, the material functions prescribing the elastic-plastic transition are extended so as to describe the inverse and reloading behavior and the strain accumulation in cyclic loading more accurately for metals exhibiting not only the cyclic hardening but also the cyclic softening behavior. The experiments on the uniaxial cyclic loading of the seamless steel pipe P110 which exhibits the cyclic softening are performed for the mechanical ratcheting and the constant strain amplitudes. The simulations to the test data are performed by using the same set of material constants. Then, the validity of the extended model for the description of cyclic loading behavior of the seamless steel pipe is verified by comparisons with the test data.

Elastoplastic deformation analysis by return-mapping and consistent tangent modulus tensor based on subloading surface model (1st Report, Formulation of return-mapping)

Elastoplastic deformation analysis by return-mapping and consistent tangent modulus tensor based on subloading surface model (1st Report, Formulation of return-mapping)

GS28 Refined Subloading Surface Model Formulation by Revisions of Translation Rules of Anisotropic Hardening and Elastic-core

GS28 Refined Subloading Surface Model Formulation by Revisions of Translation Rules of Anisotropic Hardening and Elastic-core

下負荷面モデルに基づくリターンマッピングおよび整合接線係数テンソルの導入による弾塑性変形解析（第２報，機械要素の変形解析）

The implicit stress integration algorithm was devised in the first report by formulating the return-mapping based on the cutting-plane projection and the consistent tangent modulus tensor due to the numerical method for the subloading surface model. It was incorporated into the implicit finite element program ABAQUS/Standard through the User subroutine UMAT. The high accuracy and efficiency in computation was verified by the numerical experiments adopting the one finite element subjected to the uniaxial loading under the monotonic and cyclic loadings, comparing with the calculation by the forward-Euler method under infinitesimal strain increments. In this article, the simulations of the test data for the cyclic loading under a constant strain amplitude and the small stress amplitude near the yield state are performed by the implicit finite element program, where the accurate simulation is attained. Further, the boundary-value problems, i.e. the cyclic torsional loading of the notched circular bar and the tensional loading of the flange with the hole attached to the bolt are analyzed by the program. The pertinences of these analyses are verified by comparing with the other implicit method with the nonlinear kinematic hardening model.

General Description of Elastoplastic Deformation/Sliding Phenomena of Solids in High Accuracy and Numerical Efficiency: Subloading Surface Concept

The hypoelastic-based plastic constitutive model has been developed to describe the wide class of elastoplastic deformation behavior of solids. The physical and mathematical backgrounds of the hypoelastic-based plasticity, i.e. (i) the transformation of the material-time derivative of general scalar-valued tensor function to the corotational-time derivative required for the derivation of the consistency condition fulfilling the objectivity, (ii) the requirement for the derivation of the additive decomposition of the strain rate and the continuum spin into the elastic and the plastic parts from the multiplicative decomposition of the deformation gradient, (iii) the mechanical requirements for elastoplastic constitutive equations, i.e. the continuity and the smoothness conditions and (iv) the derivation of the general loading criterion are deliberated first. Then, the subloading surface model is formulated in the framework of the hypoelastic-based plasticity. It materializes the pertinent descriptions of wide classes of deformations, i.e. the monotonic, the non-proportional and the cyclic loadings, the rate-dependent deformation behavior in a general rate up to the impact load for wide classes of materials, e.g. metals and soils and the friction phenomena between solids and further the deformation behavior of metallic materials within the framework of the crystal plasticity. In addition, it possesses the distinctive advantage in numerical analysis such that the judgment of yielding is not required in the loading criterion and the stress is automatically attracted to the yield surface in the plastic loading process, engendering a high efficiency in numerical calculations.

Finite Strain Elastoplastic Constitutive Equation Based on Subloading Surface Model

Finite Strain Elastoplastic Constitutive Equation Based on Subloading Surface Model

2912 ON CONVERGENCE RATE OF CUTTING-PLANE ALGORITHM IN NUMERICALANALYSES OF A CYCLIC PLASTICITY MODEL

The recourse to numerical techniques in plasticity has become a crucial point to speed up computational time The nonlinear behavior of material forces the use of a small step size in order to keep the accuracy of the solution and the stability of the algorithm Return Mapping technique [1], here adapted to the Subloading Surface model [2], guarantees a quadratic convergence rate on the correct solution even in a large step analysis, justifying its use especially where a large number of iterations is required (cyclic plasticity problems, etc) and reducing the computing effort

Elastoplastic model of metals with smooth elastic–plastic transition

The subloading surface model is based on the simple and natural postulate that the plastic strain rate develops as the stress approaches the yield surface. It therefore always describes the continuous variation of the tangent modulus. It requires no incorporation of an algorithm for the judgment of yielding, i.e., a judgment of whether or not the stress reaches the yield surface. Furthermore, the calculation is controlled to fulfill the consistency condition. Consequently, the stress is attracted automatically to the normal-yield surface in the plastic loading process even if it goes out from that surface. The model has been adopted widely to the description of deformation behavior of geomaterials and friction behavior. In this article, it is applied to the formulation of the constitutive equation of metals by modifying the past formulation of this model. This modification enables to avoid the indetermination of the subloading surface, to make the reloading curve recover promptly to the preceding loading curve, and to describe the cyclic stagnation of isotropic hardening. The applicability of the present model to the description of actual metal deformation behavior is verified through comparison with various cyclic loading test data.

J031012 拡張下負荷面モデルの金属材料塑性繰返し変形解析への適用

The extended subloading surface model, which has the mathematical structure to describe the cyclic loading behavior, was successfully implemented to the commercial finite element code ABAQUS. The applicability of the model was verified by the simulations of some test data of simple steel structures.

Unconventional finite strain theory based on the subloading surface model: II. Numerical analysis

Unconventional finite strain theory based on the subloading surface model: II. Numerical analysis

3D subsidence analyses above gas reservoirs accounting for an unconventional plasticity model

SUMMARYThe coupled hydro‐mechanical state in soils coming from consolidation/subsidence processes and undergoing plasticity phenomena is here evaluated by means of the subloading surface model. The most important feature of this theory is the abolition of the distinction between the elastic and plastic domains, as it happens in the conventional elastoplastic models. This means that plastic deformations are generated whenever there is a change in stress and a smoother elastoplastic transition is produced. The plasticity algorithm has been implemented in the PLASCON3D FE code, coupling hydro‐thermo‐mechanical fields within a saturated (locally partially saturated) porous medium subjected to external loads and water/gas withdrawals from deep layers (aquifers/reservoirs). The 3D model has been first calibrated and validated against examples taken from the literature, and then subsidence analyses at regional scales due to gas extractions have been developed to predict the evolution of settlements and pore pressure in soils for long‐term scenarios. Copyright © 2011 John Wiley & Sons, Ltd.