scholarly journals A Study of Yielding and Plasticity of Rapid Prototyped ABS

Mathematics ◽  
2021 ◽  
Vol 9 (13) ◽  
pp. 1495
Author(s):  
Dan-Andrei Șerban ◽  
Cosmin Marșavina ◽  
Alexandru Viorel Coșa ◽  
George Belgiu ◽  
Radu Negru
Keyword(s):  
Experimental Data ◽  
Stress State ◽  
Plastic Flow ◽  
Plane Stress ◽  
Yield Criterion ◽  
Numerical Analyses ◽  
Flow Potential ◽  
Stress States ◽  
State Configuration

In this article, the yielding and plastic flow of a rapid-prototyped ABS compound was investigated for various plane stress states. The experimental procedures consisted of multiaxial tests performed on an Arcan device on specimens manufactured through photopolymerization. Numerical analyses were employed in order to determine the yield points for each stress state configuration. The results were used for the calibration of the Hosford yield criterion and flow potential. Numerical analyses performed on identical specimen models and test configurations yielded results that are in accordance with the experimental data.

An Analytical Solution to Metal Plane Problem in Terms of Orthotropic Anisotropy and Strain Hardening

2010 ◽  
Vol 97-101 ◽  
pp. 348-356
Author(s):  
Yao He Liu ◽  
Guo Feng Yi ◽  
Jian Ming Xiong
Keyword(s):  
Stress State ◽  
Analytical Solution ◽  
Plane Stress ◽  
Yield Criterion ◽  
Research Result ◽  
Yield Condition ◽  
Plane Stress State ◽  
Yield Function ◽  
Anisotropic Parameter ◽  
Symmetric Plane

In this paper, the yield condition of Hill’s orthotropic yield criterion under axial symmetric plane stress state was discussed. The yield function of orthotropic material was proposed and the analytical solution to meet the condition of equations of equilibrium and compatibility under axial symmetric plane stress state is obtained, in which the conditions of power hardening materials was considered. The research result indicates that hardening coefficient and anisotropic parameter have substantial influence over stress and strain. However, in the presence of the coefficient R90=H/F，the influence appears to be quite weak.

A theory of the yield locus and flow rule of anisotropic materials

1966 ◽  
Vol 1 (3) ◽  
pp. 204-215 ◽  
Author(s):  
T. C. Hsu
Keyword(s):  
Experimental Data ◽  
Linear Relationship ◽  
Yield Stress ◽  
Plane Stress ◽  
Stress Ratio ◽  
Yield Criterion ◽  
Anisotropic Materials ◽  
Yield Locus ◽  
Flow Rule ◽  
Stress Components

A general yield criterion for anisotropic materials is derived from the linear relationship between strain and stress components. The particular forms of the yield criterion for plane stress and for certain types of symmetry are discussed and are compared with available experimental data. The separate effects of the stress ratio and the direction of the stress axes on the yield stress are also determined.

COMBINED EXTRUSION OF GLASSES WITH A CONICAL BOTTOM. KINEMATIC AND STRESS STATES OF THE PLASTIC REGION LOCATED UNDER THE CONICAL SURFACE OF THE PUNCH

2021 ◽  
pp. 2-7 ◽  
Author(s):  
A. L. Vorontsov ◽  
D. A. Lebedeva
Keyword(s):  
Plastic Deformation ◽  
Stress State ◽  
Plastic Flow ◽  
Mathematical Analysis ◽  
Plastic Region ◽  
Conical Surface ◽  
Flat Part ◽  
The Future ◽  
Stress States ◽  
Conical Bottom

For extrusion of glasses with a conical bottom using the method of plastic flow by A. L. Vorontsov, the kinematic and stress states of the extruded metal in the area of the plastic deformation center located under the conical surface of the punch were determined. The resulting formulas will be used to determine the stress state in the region of the hearth located under the central flat part of the punch-son՚s working end. In the future, the results of this mechanical and mathematical analysis will also make it possible to investigate the question of the presence of the taper of the punch, which is optimal in terms of strength.

scholarly journals On Phenomenological Failure Loci of Metals under Constant Stress States of Combined Tension and Shear: Issues of Coaxiality and Non-Uniqueness

Metals ◽  
2019 ◽  
Vol 9 (10) ◽  
pp. 1052
Author(s):  
Cliff Butcher ◽  
Armin Abedini
Keyword(s):  
Stress State ◽  
Plane Stress ◽  
Simple Shear ◽  
Stress Triaxiality ◽  
Failure Surface ◽  
Equivalent Strain ◽  
Shear Loading ◽  
Stress Conditions ◽  
Failure Locus ◽  
Stress States

The present study investigates how the choice of characterization test and the composition of the stress state in terms of tension and shear can produce a non-unique failure locus in terms of stress triaxiality under plane stress conditions. Stress states that are composed of tensile and simple shear loadings result in a loss of proportionality between the cumulative strain and stress such that the principal frames become non-coaxial despite a constant stress triaxiality. Consequently, it is shown that the conventional interpretation of a failure locus in plane stress is based upon an implicit assumption of proportional coaxial loading. The use of simple shear tests along with traditional in-plane tensile tests for fracture characterization is only one “path” that can be taken in terms of the stress triaxiality, which may produce a bifurcation at uniaxial tension while the tension–torsion path does not. In general, the failure locus in terms of the equivalent strain is a failure surface and must consider the composition of the stress state that produces a given triaxiality. A comprehensive review of phenomenological fracture loci within a modified Mohr-Coulomb (MMC) framework is performed to highlight how the choice of stress states obtained using different characterization tests can change the apparent fracture locus of a material. The finite strain solutions for the work conjugate equivalent strain are derived for various loading paths that produce the same stress triaxiality. It is then shown that accounting for non-coaxiality leads to equivalent failure strains that are even higher than previously reported in tension–torsion tests within the literature. The equivalent plastic strains integrated from finite-element simulations are work-conjugate by definition. The equivalent strains estimated from the cumulative principal strains using DIC strain measurement depend upon a coaxial or non-coaxial assumption. Finally, an analytical solution for the onset of diffuse necking that accounts for the stabilizing influence of shear loading against a tensile instability is considered. Even under plane stress conditions, a failure surface arises in terms of the equivalent strain at necking, the stress triaxiality, and the severity of shear loading.

Plane-Stress Analysis of the New Stress Tensor Decomposition

2013 ◽  
Vol 315 ◽  
pp. 635-639 ◽  
Author(s):  
Mohd Khir Mohd Nor ◽  
Rade Vignjevic ◽  
James Campbell
Keyword(s):  
Experimental Data ◽  
Stress Tensor ◽  
Plane Stress ◽  
Yield Criterion ◽  
Tensor Decomposition ◽  
Alloy Sheet ◽  
Stress Conditions ◽  
Orthotropic Materials ◽  
Deviatoric Plane ◽  
Plane Stress Analysis

The accuracy and reliability of the new stress tensor decomposition to capture the plasticity behaviour of orthotropic materials under plane-stress conditions was examined in this paper. No experiment was required to perform this work. Therefore, the suitable, published paper which provides a relevant test result and sufficient material properties to characterise the new stress tensor decomposition, was used. This new stress tensor decomposition was used to presents a new yield criterion for orthotropic sheet metals under plane-stress conditions in this work. This was done by assuming the yield surface to be circular in the new deviatoric plane. The predictions of the new effectice stress expression were then compared with the experimental data of 6000 series aluminium alloy sheet (A6XXX-T4) and Al-killed cold-rolled steel sheet SPCE. The predicted new yield surfaces are in good agreement with respect to the experimental data for two materials (A6XXX-T4 and SPCE).

COMBINED EXTRUSION OF GLASSES WITH A CONICAL BOTTOM. KINEMATIC AND STRESS STATES OF A CYLINDRICAL PLASTIC REGION LOCATED UNDER THE FORMING GLASS WALL

2021 ◽  
pp. 13-18 ◽  
Author(s):  
A. L. Vorontsov ◽  
D. A. Lebedeva
Keyword(s):  
Plastic Deformation ◽  
Stress State ◽  
Plastic Flow ◽  
Plastic Region ◽  
Glass Wall ◽  
Cylindrical Section ◽  
The Matrix ◽  
Stress States ◽  
Conical Bottom

For extrusion of glasses with a conical bottom using the method of plastic flow by A. L. Vorontsov, the kinematic and stress states of the extruded metal in the area of the plastic deformation center located under the formed wall of the glass and adjacent to the cylindrical section of the matrix were determined. The resulting formulas will be used to determine the stress state in the areas of the focus located under the punch end.

MODERN STRENGTH CRITERIA FOR CONCRETE UNDER TRIAXIAL STRESS STATES

2021 ◽  
Vol 97 (5) ◽  
pp. 16-30
Author(s):  
V.I. KORSUN ◽  
◽  
S.N. KARPENKO ◽  
S.Yu. MAKARENKO ◽  
A.V. NEDOREZOV ◽  
...  
Keyword(s):  
Experimental Data ◽  
Stress State ◽  
Concrete Strength ◽  
Plane Stress State ◽  
Triaxial Stress ◽  
Design Strength ◽  
Strength Criteria ◽  
Analysis And Design ◽  
Reliable Assessment ◽  
Stress States

Reliable assessment of the strength and deformations of concrete under multiaxial stress states is important for increasing the accuracy of analysis and design. Classical strength theories do not work for such materials as concrete due to the complex shear-pryout mechanism of its structural failure. Description of the key relations of strength criteria established by G.A. Geniev, G.A. Geniev – N.M. Alikova, E.S. Leites, A.V. Yashin, S.F. Klovanich – D.I. Bezushko, K.J. Willam – E.P. Warnke and N.I. Karpenko is given. Assessment of the compliance of the design strength with the experimental data under uni-, bi- and triaxial stress states is made. Strength criteria that most closely describe the experimental data in the specific areas of the stress state are determined. It has been found out that the most developed strength conditions are the ones developed by S.F. Klovanich – D.I. Bezushko, K.J. Willam – E.P. Warnke and N.I. Karpenko. The criteria introduced by E.S. Leites and A.V. Yashin describe the experimental data under conditions of the plane stress state with sufficient accuracy. The strength conditions established by G.A. Geniev and G.A. Geniev – N.M. Alikova require careful use, taking into account their deviations from the experimental data in certain areas of triaxial stress states. Loading programs in the process of experimental research of concrete strength aimed at identifying the forms of functions of meridional and deviatoric curves more accurately have been determined.

Short Stress State Questionnaire

2015 ◽  
Vol 31 (1) ◽  
pp. 20-30 ◽  
Author(s):  
William S. Helton ◽  
Katharina Näswall
Keyword(s):  
Stress State ◽  
Factor Structure ◽  
Human Performance ◽  
Self Report ◽  
Confirmatory Factor ◽  
Stress States ◽  
Related Stress ◽  
Using Data ◽  
Task Conditions ◽  
Multiple Samples

Conscious appraisals of stress, or stress states, are an important aspect of human performance. This article presents evidence supporting the validity and measurement characteristics of a short multidimensional self-report measure of stress state, the Short Stress State Questionnaire (SSSQ; Helton, 2004 ). The SSSQ measures task engagement, distress, and worry. A confirmatory factor analysis of the SSSQ using data pooled from multiple samples suggests the SSSQ does have a three factor structure and post-task changes are not due to changes in factor structure, but to mean level changes (state changes). In addition, the SSSQ demonstrates sensitivity to task stressors in line with hypotheses. Different task conditions elicited unique patterns of stress state on the three factors of the SSSQ in line with prior predictions. The 24-item SSSQ is a valid measure of stress state which may be useful to researchers interested in conscious appraisals of task-related stress.

Sign in / Sign up

Export Citation Format

Share Document