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 ◽  
...  

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.

Mathematics ◽  
2021 ◽  
Vol 9 (13) ◽  
pp. 1495
Author(s):  
Dan-Andrei Șerban ◽  
Cosmin Marșavina ◽  
Alexandru Viorel Coșa ◽  
George Belgiu ◽  
Radu Negru

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.


1988 ◽  
Vol 41 (2) ◽  
pp. 189 ◽  
Author(s):  
RA Winholtz ◽  
JB Cohen

The determination of residual stresses via X-ray diffraction is briefly reviewed, with particular emphasis on the triaxial stress state. A new method is proposed for determining the general stress tensor, which considerably reduces the variances of the stresses due to counting statistics and gradients. The procedure involves a generalised least-squares solution of strains measured at various tilts of the X-ray beam to the sample, and a new set of tilts is recommended to minimise these errors.


Author(s):  
Konstantin P. Pyatikrestovsky

Aims of research. The task is to apply modern strength criteria of anisotropic materials for the calculation of multilayer walls made of cellular concrete and silicate large masonry materials, which differ in exact dimensions and allow for thin-seam masonry with adhesive seams. Proposals for the inclusion in the design standards of guidance that takes into account the work of wall materials in complex stress states will be presented in a series of publications. Methods. The strength criteria of G.A. Geniev in a rather simplified form are used. The volumetric stress state of walls made of orthotropic materials is considered. The basis for the construction of strength criteria are three possible different mechanisms of destruction - separation, compression and shear. For modern thin-walled masonry is characterized by a combination of compressive (vertical) and shear (horizontal) loads. Of particular interest is the work of the masonry shift, since the plane stress state is not sufficiently studied. The article is devoted to the construction of the criterion of masonry shear strength. The peculiarity of the proposed calculations is the comparative simplicity of the strength criteria due to the accepted hypotheses. Results. The final expression of the shear strength criterion and the sequence of the shear strength verification in the case of simple loading are presented. The article is preliminary for a series of calculations and results of experimental studies of the walls under different operating conditions and different loads.


2007 ◽  
Vol 1025 ◽  
Author(s):  
Bun H Chua ◽  
Abhijit Chandra ◽  
Pranav Shrotriya

AbstractThe focus of this paper is to investigate the synergistic influence of contact loads, surface stress state and chemical environment on material removal during mechanical stimulation of copper surface. A unique setup is used to generate well characterized stress states on a polished copper specimen. Stressed surface of copper specimen is stimulated using tip of the atomic force microscope (AFM) and material removed during stimulation is measured as a function of contact loads, surface stress state and chemical environment. Measured material removal rates display a complex dependence on contact pressures and in-plane stress state which changes as the pH of chemical environment changes from acidic to basic. A surface material removal mechanism based on a single asperity wear and stress-assisted dissolution is proposed to explain the experimental observations


2015 ◽  
Vol 31 (1) ◽  
pp. 20-30 ◽  
Author(s):  
William S. Helton ◽  
Katharina Näswall

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.


Materials ◽  
2021 ◽  
Vol 14 (5) ◽  
pp. 1099
Author(s):  
Qingqing Chen ◽  
Yuhang Zhang ◽  
Tingting Zhao ◽  
Zhiyong Wang ◽  
Zhihua Wang

The mechanical properties and fracture behaviour of concretes under different triaxial stress states were investigated based on a 3D mesoscale model. The quasistatic triaxial loadings, namely, compression–compression–compression (C–C–C), compression–tension–tension (C–T–T) and compression–compression–tension (C–C–T), were simulated using an implicit solver. The mesoscopic modelling with good robustness gave reliable and detailed damage evolution processes under different triaxial stress states. The lateral tensile stress significantly influenced the multiaxial mechanical behaviour of the concretes, accelerating the concrete failure. With low lateral pressures or tensile stress, axial cleavage was the main failure mode of the specimens. Furthermore, the concretes presented shear failures under medium lateral pressures. The concretes experienced a transition from brittle fracture to plastic failure under high lateral pressures. The Ottosen parameters were modified by the gradient descent method and then the failure criterion of the concretes in the principal stress space was given. The failure criterion could describe the strength characteristics of concrete materials well by being fitted with experimental data under different triaxial stress states.


2017 ◽  
Vol 755 ◽  
pp. 300-321 ◽  
Author(s):  
Volodymyr I. Korsun ◽  
Yu.Yu. Kalmykov ◽  
S.Yu. Makarenko

The paper is about the generally accepted in the deformable solid mechanics principles of constructing limiting surfaces of concrete strength in the principal stress space. The background and theoretical approaches taken by different researchers to describe the functions of deviatoric and meridional curves as the basic elements which determine the surface configuration of concrete strength were analyzed.There was carried out a comparative analysis of different authors’ suggestions on an analytic description of concrete strength for different stress states and a comparison of the developed criteria and the results of short-term tests of plane concrete under multiaxial loadings. Comparing the methods taken for developing the interpolation functions of deviatoric and meridional curves, it was inferred that the application of different approaches to the development of concrete failure criteria is effective. Keeping in mind the results of the comparative analysis of the prerequisites taken to develop the above failure criteria and the requirements of a better approximation of the experimental data, there are made new suggestions to describe concrete strength for the general case of stress state.


2012 ◽  
Vol 253-255 ◽  
pp. 456-461
Author(s):  
Yan Fu Qin ◽  
Bin Tian ◽  
Gang Xu ◽  
Xiao Chun Lu

Frost resistance research is one of the important subject of concrete durability, however strength criteria is an important part of the study of mechanical behavior of concrete. So far, about concrete failure criteria are almost for normal concrete, which the domestic and overseas scholars have comparative detailed research in every respect to it, and to freeze-thaw damage of concrete but few research. Based on the summary of the existing ordinary concrete strength and failure criteria in normal state and after freeze-thaw damage,this paper have a brief comment of failure criteria on concrete after freeze-thaw damage. For later research about concrete strength and failure criteria under freezing and thawing cycle provide the reference.


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