• Title/Summary/Keyword: Tresca yield condition

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Undrained solution for cavity expansion in strength degradation and tresca soils

  • Li, Chao;Zou, Jin-feng;Sheng, Yu-ming
    • Geomechanics and Engineering
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    • v.21 no.6
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    • pp.527-536
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    • 2020
  • An elastic-plastic solution for cavity expansion problem considering strength degradation, undrained condition and initial anisotropic in-situ stress is established based on the Tresca yield criterion and cavity expansion theory. Assumptions of large-strain for plastic region and small-strain for elastic region are adopted, respectively. The initial in-situ stress state of natural soil mass may be anisotropic caused by consolidation history, and the strength degradation of soil mass is caused by structural damage of soil mass in the process of loading analysis (cavity expansion process). Finally, the published solutions are conducted to verify the suitability of this elastic-plastic solution, and the parametric studies are investigated in order to the significance of this study for in-situ soil test.

Simulation of Explosion Using the Ideal Viscoelastic Object Yield Condition (이상적인 점탄성체 항복 조건을 이용한 폭발 시뮬레이션)

  • Sung, Su-Kyung;Kim, Gyeong-Su;Shin, Byeong-Seok
    • Journal of Korea Game Society
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    • v.14 no.6
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    • pp.49-58
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    • 2014
  • In particle-based fluid simulation, the yield stress is required for the deformation of the viscoelastic material like gel. von Mises's yield condition has been proposed to implement deformation of viscoelastic objects, but did not express the explosion. Furthermore, von Mises's yield condition is hard to approximate. We propose an ideal yield condition for viscoelastic object that reference from Tresca's yield condition. Unlike conventional particle-based simulation approximate the external power by the deformed length of the object, this paper is approximate the external power by area of the object. We check up that explosion was realistic when a viscoelastic object is compressed under the ideal yield condition.

Kinematics of the Nonsteady Axi-symmetric Ideal Plastic Flow Process

  • Alexandrov, S.;Lee, W.;Chung, K.
    • Fibers and Polymers
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    • v.5 no.3
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    • pp.209-212
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    • 2004
  • A nonsteady axi-symmetric ideal flow solution is obtained here. It is based on the rigid perfect-plastic constitutive law with the Tresca yield condition and its associated flow rule. The process is to deform a circular solid disk into a spherical shell of prescribed geometry. It is assumed that there are no rigid zones and friction stresses. The solution obtained provides the distribution of kinematic variables and involves one undetermined function of the time. This function can be in general found by superimposing an optimality criterion.

Thermoelastoplastic response of FGM linearly hardening rotating thick cylindrical pressure vessels

  • Ebrahimi, Tayebeh;Nejad, Mohammad Zamani;Jahankohan, Hamid;Hadi, Amin
    • Steel and Composite Structures
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    • v.38 no.2
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    • pp.189-211
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    • 2021
  • An analytical solution is presented to analyze the thermoelastoplastic response of a rotating thick-walled cylindrical pressure vessel made of functionally graded material (FGM). The analysis is based on Tresca's yield condition, its associated flow rule and linear strain hardening material behaviour. The uncoupled theory of thermoelasticity is used, and the plane strain condition is assumed. The material properties except for Poisson's ratio, are assumed to vary nonlinearly in the radial direction. Elastic, partially plastic, fully plastic, and residual stress states are investigated. The heat conduction equation for the one-dimensional problem in cylindrical coordinates is used to obtain temperature distribution in the vessel. It is assumed that the inner surface is exposed to an airstream and that the outer surface is exposed to a uniform heat flux. Tresca's yield criterion and its associated flow rule are used to formulate six different plastic regions for a linearly hardening condition. All these stages are studied in detail. It is shown that the thermoelastoplastic stress response of a rotating FGM pressure vessel is affected significantly by the nonhomogeneity of the material and temperature gradient. The results are validated with those of other researchers for appropriate values of the system parameters and excellent agreement is observed.

Complete lower bound solutions of circular plate collapse problems by a finite difference method (원형평판의 붕괴문제에 관한 유한차분 완전 하계해)

  • Huh, Hoon
    • Transactions of the Korean Society of Mechanical Engineers
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    • v.14 no.6
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    • pp.1382-1390
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    • 1990
  • Accurate load-carrying capacities and moment distributions of thin circular plates are obtained for clamped or simply-supported boundary condition under various concentrated circular loadings. The material is regarded as perfectly-plastic based on an arbitrary yield function such as the Tresca yield function, the Johansen yield function, and the farmily of .betha.-norms which possesses the von Mises yield function and the Frobenius norm. To obtain the lower bound solutions, a maximization formulation is derived and implemented for efficient numerical calculation with a finite difference method and the modified Newton's method. The numerical results demonstrate plastic collapse behavior of circular plates and provide their design criteria.

Exact thermoelastoplastic analysis of FGM rotating hollow disks in a linear elastic-fully plastic condition

  • Nadia Alavi;Mohammad Zamani Nejad;Amin Hadi;Anahita Nikeghbalyan
    • Steel and Composite Structures
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    • v.51 no.4
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    • pp.377-389
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    • 2024
  • In the present study, thermoelsatoplastic stresses and displacement for rotating hollow disks made of functionally graded materials (FGMs) has been investigated. The linear elastic-fully plastic condition is considered. The material properties except Poisson's ratio are assumed to vary in the radial direction as a power-law function. The heat conduction equation for the one-dimensional problem in cylindrical coordinates is used to obtain temperature distribution in the disk. The plastic model is based on the Tresca yield criterion and its associated flow rules under the assumption of perfectly plastic material behavior. Exact solutions of field equations for elastic and plastic deformations are obtained. It is shown that the elastoplastic response of the functionally graded (FG) disk is affected notably by the radial variation of material properties. It is also shown that, depending on material properties and disk dimensions, different modes of plastic deformation may occur.