scholarly journals More on Plastic Yield Criteria

2021 ◽  
Vol 9 (6) ◽  
Keyword(s):  
1979 ◽  
Vol 46 (3) ◽  
pp. 701-703 ◽  
Author(s):  
R. M. Haythornthwaite

2014 ◽  
Vol 611-612 ◽  
pp. 3-10
Author(s):  
Wilko C. Emmens ◽  
A.H. van den Boogaard

This work investigates the relation between shear stress and plastic yield considering that a crystal can only deform in a limited set of directions. The shear stress in arbitrary directions is mapped for some cases showing relevant differences. Yield loci based on mean shear stress are constructed. The Tresca yield criterion can be improved by averaging the shear stress over directions near the direction of maximum shear stress. Yield criteria based on averaging over crystallographic direction show a clear influence of the actual orientation of these direction, notably in case of few crystallographic directions. The general finding is that the higher the isotropy of a material, the lower the plane strain factor. The shape of the yield loci is comparable to those derived by the Hershey criterion with exponents lower than 3.


Author(s):  
Xian-Kui Zhu ◽  
Brian N. Leis

This paper theoretically investigates the effect of axial tensile strain on the plastic yield load-carrying capacity of pipelines. The elasticity theory and three plastic yield criteria of Tresca criterion, von Mises criterion, and Average Shear Stress Yield (ASSY) criterion are adopted in the analysis. General solutions of elastic stresses and strains are obtained for a thin-walled, end-caped pipe subjected to internal pressure and an axial strain that is used to represent the outside applied force. Based on the three plastic yield criteria, different nonlinear governing equations are obtained for determining the yield pressure, the yield hoop and axial stresses as well as the yield hoop and radial strains for the pipe. The results showed that the pressure, stresses and strains in the pipe at yield are functions of the axial strain, Poisson’s ratio, Young’s modulus, and yield strength of the pipe steel. The tensile strain limits are then obtained for different pipeline grades. It is concluded that the axial tensile strain can significantly reduce the limit load or the regulation-allowed operating pressure, and the tensile strain limits should be considered in strain-based design to prevent pipeline failure.


2019 ◽  
Vol 10 (4) ◽  
pp. 769-791 ◽  
Author(s):  
Norbert Ortner ◽  
Peter Wagner

Abstract Several formulas for the eigenvalues $$\lambda _j$$ λ j of the Weyl transforms $$W_\sigma $$ W σ of symbols $$\sigma $$ σ given by radially symmetric distributions are derived. These yield criteria for the boundedness and the compactness, respectively, of the pseudo-differential operators $$W_\sigma .$$ W σ . We investigate some examples by analyzing the asymptotic behavior of $$\lambda _j$$ λ j for $$j\rightarrow \infty $$ j → ∞ .


2013 ◽  
Vol 351-352 ◽  
pp. 1552-1557
Author(s):  
Da Guo Wang ◽  
Zhi Xiu Wang ◽  
Bing Xu

Based on micromechanics, an elastic-plastic-brittle damage model of concrete beam reinforced with stick steel is proposed by considering the aggregate gradation curve algorithms and the heterogeneity. In the model, the concrete beam reinforced with stick steel is taken as a five-phase composite material that consists of the mortar matrix, coarse aggregate, bonds between mortar and aggregate, steel plate, and the adhesive layer between steel plate and concrete beam. Through the numerical investigation on shear failure of concrete beam reinforced with stick steel under external force, the results show that the model can clearly simulate microscopic plastic yield, and the initiation and extension of crack. The strength of the steel plate is relatively stronger, so it cant enhance the shear capability of the each side of the beam and the concrete beam bears the larger shear stress, which results that a large number of elements, from the supports to the load points, begin to yield. When the strain of the elements exceeds the yield strength, the elements will produce failure until the failure of the whole specimen. The final failure mode of concrete beam reinforced with stick steel is the shear failure.


2017 ◽  
Vol 2017 ◽  
pp. 1-12 ◽  
Author(s):  
Jun Ding ◽  
Lu-sheng Wang ◽  
Kun Song ◽  
Bo Liu ◽  
Xia Huang

The crack propagation process in single-crystal aluminum plate (SCAP) with central cracks under tensile load was simulated by molecular dynamics method. Further, the effects of model size, crack length, temperature, and strain rate on strength of SCAP and crack growth were comprehensively investigated. The results showed that, with the increase of the model size, crack length, and strain rate, the plastic yield point of SCAP occurred in advance, the limit stress of plastic yield decreased, and the plastic deformability of material increased, but the temperature had less effect and sensitivity on the strength and crack propagation of SCAP. The model size affected the plastic deformation and crack growth of the material. Specifically, at small scale, the plastic deformation and crack propagation in SCAP are mainly affected through dislocation multiplication and slip. However, the plastic deformation and crack propagation are obviously affected by dislocation multiplication and twinning in larger scale.


2017 ◽  
Vol 751 ◽  
pp. 167-172 ◽  
Author(s):  
Sansot Panich ◽  
Nopparat Seemuang ◽  
Taratip Chaimongkon

In this work, the experimental and numerical analyses of Forming Limit Curve (FLC) and Forming Limit Stress Curve (FLSC) for Advanced High Strength Steel (AHSS) sheet, grade JAC780Y, are performed. Initially, the FLC is experimentally determined by means of the Nakazima Stretch forming test. Subsequently, the FLSC of investigated steel was plastically calculated using the experimental FLC data. Different yield criteria including Hill48, and Yld89, are applied to describe plastic flow behavior of the AHS steel and Swift hardening law is taken into account. Hereby, influences of the constitutive yield models on the numerically determined FLSCs are evaluated regarding to those results from the experimental data. The obtained stress based forming limits are affected significantly by the yield criteria. Finally, the experimental and numerical formability analyses of Fukui stretch-drawing and square cup drawing tests are studied through FLC and FLSCs. It is observed that all stress based curves can be used very well to describe material formability of the examined steel compared to the strain based FLC. The strain based FLC depend on forming history and strain paths change. In the other hand, the stress based FLC do not depend on these issue. In this study, it can be concluded that the FLSCs could predict failure more realistically and better than the strain based FLC.


Author(s):  
Moriaki GOYA ◽  
Shigeru NAGAKI ◽  
Robert SOWERBY
Keyword(s):  

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