Liping Zu¹, Yaxun Liu¹, Haoran Zhang¹, Lisheng Liu^2,*, Xin Lai^2,*, Hai Mei²

CMES-Computer Modeling in Engineering & Sciences, Vol.140, No.3, pp. 2349-2371, 2024, DOI:10.32604/cmes.2024.050488

Abstract Fracture in ductile materials often occurs in conjunction with plastic deformation. However, in the bond-based peridynamic (BB-PD) theory, the classic mechanical stress is not defined inherently. This makes it difficult to describe plasticity directly using the classical plastic theory. To address the above issue, a unified bond-based peridynamics model was proposed as an effective tool to solve elastoplastic fracture problems. Compared to the existing models, the proposed model directly describes the elastoplastic theory at the bond level without the need for additional calculation means. The results obtained in the context of this model are shown More >

İlyas Kacar^*

CMES-Computer Modeling in Engineering & Sciences, Vol.128, No.1, pp. 87-108, 2021, DOI:10.32604/cmes.2021.015227

Abstract Locking nuts are widely used in industry and any defects from their manufacturing may cause loosening of the connection during their service life. In this study, simulations of the folding process of a nut’s flange made from AISI 1040 steel are performed. Besides the bilinear isotropic hardening rule, Chaboche’s nonlinear kinematic hardening rule is employed with associated flow rule and Hill48 yield criterion to set a plasticity model. The bilinear isotropic hardening rule’s parameters are determined by means of a monotonic tensile test. The Chaboche’s parameters are determined by using a low cycle tension/compression test… More >

Igor Karšaj¹, Carlo Sansour², Jurica Sorić¹

CMES-Computer Modeling in Engineering & Sciences, Vol.8, No.1, pp. 45-60, 2005, DOI:10.3970/cmes.2005.008.045

Abstract In this paper, a free energy-based formulation incorporating the effect of kinematic hardening is proposed. The formulation is able to reproduce symmetric expressions for the back stress while incorporating the multiplicative decomposition of the deformation gradient. Kinematic hardening is combined with isotropic hardening where an associative flow rule and von Mises yield criterion are applied. An accurate and trivial wise objective integration algorithm employing the exponential map is developed. In order to ensure a high convergence rate in the global iteration approach, an algorithmic tangent operator is derived. The computational algorithm is implemented and applied More >

S.-Y. Leu¹, J.T. Chen²

CMES-Computer Modeling in Engineering & Sciences, Vol.14, No.2, pp. 129-140, 2006, DOI:10.3970/cmes.2006.014.129

Abstract Plastic limit angular velocity of rotating hollow cylinders made of the von Mises materials with nonlinear isotropic hardening is investigated numerically and analytically in the paper. The paper applies sequential limit analysis to deal with the rotating problems involving hardening material property and weakening behavior resulted from the widening deformation. By sequential limit analysis, the paper treats the plasticity problems as a sequence of limit analysis problems stated in the upper bound formulation. Rigorous upper bounds are acquired iteratively through a computational optimization procedure with the angular velocity factor as the objective function. Especially, rigorous More >