Multiaxial Failure Criteria for Cellular Materials

1990 ◽  
Vol 207 ◽  
Author(s):  
T. C. Triantafillou ◽  
L. J. Gibson
Keyword(s):  
Stress State ◽  
Brittle Fracture ◽  
Engineering Design ◽  
Failure Criteria ◽  
Cellular Materials ◽  
Elastic Buckling ◽  
Cellular Solids ◽  
Plastic Yield ◽  
Proper Design

AbstractCellular materials are increasingly used in engineering. Proper design requires an understanding of the response of the materials to stress; and, in real engineering design, the stress state is often a complex one. In this paper we model the elastic buckling, plastic yield, and brittle fracture of cellular solids under multiaxial stresses to develop equations describing their failure surfaces. Comparison of the analysis with data shows that the models describe the main features of the multiaxial behavior of foams well.

scholarly journals Failure criteria for C/SiC composites under plane stress state

2014 ◽  
Vol 4 (2) ◽  
pp. 021007 ◽  
Author(s):  
Chengpeng Yang ◽  
Guiqiong Jiao ◽  
Hongbao Guo
Keyword(s):  
Stress State ◽  
Plane Stress ◽  
Failure Criteria ◽  
Plane Stress State ◽  
Sic Composites

scholarly journals An independent derivation and verification of the voids nucleation failure mechanism: significance for materials failure

2019 ◽  
Vol 475 (2222) ◽  
pp. 20180755 ◽  
Author(s):  
Richard Christensen ◽  
Zhi Li ◽  
Huajian Gao
Keyword(s):  
Stress State ◽  
Failure Mechanism ◽  
Density Functional ◽  
Failure Modes ◽  
Shear Bands ◽  
Failure Criteria ◽  
Atomic Scale ◽  
Ideal Strength ◽  
Failure Theory ◽  
The Ideal

Independent derivations are given for the failure criteria of the purely dilatational stress state involving voids nucleation failure as well as for the purely distortional stress state involving shear bands failure. The results are consistent with those from a recently derived failure theory and they further substantiate the failure theory. The voids nucleation mechanism is compared with the ideal theoretical strength of isotropic materials as derived by density functional theory and two other atomic-scale methods. It is found that a cross-over occurs from the voids nucleation failure mechanism to the ideal strength limitation as the tensile to compressive strengths ratio, T / C , increases toward a value of unity. All the results are consistent with the failure modes transition results from the general failure theory.

Failure Criteria for Unidirectional Fiber Composites

1980 ◽  
Vol 47 (2) ◽  
pp. 329-334 ◽  
Author(s):  
Z. Hashin
Keyword(s):  
Stress State ◽  
Failure Modes ◽  
Three Dimensional ◽  
Transversely Isotropic ◽  
Failure Surface ◽  
Failure Criteria ◽  
Fiber Composites ◽  
Piecewise Smooth ◽  
Average Stress ◽  
Unidirectional Fiber

Three-dimensional failure criteria of unidirectional fiber composites are established in terms of quadratic stress polynomials which are expressed in terms of the transversely isotropic invariants of the applied average stress state. Four distinct failure modes—tensile and compressive fiber and matrix modes—are modeled separately, resulting in a piecewise smooth failure surface.

scholarly journals Research on Fuzzy Plastic Constitutive Model Based on Membership Function

2021 ◽  
Vol 2021 ◽  
pp. 1-13
Author(s):  
Xigang Wang ◽  
Liling Jin ◽  
Mingfu Fu
Keyword(s):  
Stress State ◽  
Cyclic Loading ◽  
Yield Point ◽  
Membership Function ◽  
Yield Function ◽  
Loading Path ◽  
Fuzzy Mathematics ◽  
Model Based ◽  
Plastic Yield ◽  
The Membership Function

Soil has no obvious yield point, and the classical elastoplastic theory contradicts the uncertainty of the plastic yield point of the soil. Therefore, a fuzzy plastic Cambridge model based on the membership function was designed by combining the fuzzy mathematics with the Cambridge model. This model made the plastic membership function to correspond with the fuzzy yield function. The plastic strain at any stress state was calculated using the fuzzy Cambridge model and was compared with the indoor triaxial test results, and they were in good agreement. Therefore, it is appropriate to use fuzzy mathematics to express the unobvious soil yield property. The characteristics of soil yield in any stress state is reflected by the fuzzy plastic theory, which indicates that there is entirely no elasticity at any stress state. Moreover, the varying degrees of plasticity and the degree of plastic yield were uniquely determined by the plastic membership function. The fuzzy plastic model used the membership function change to replace the complex hardening. Additionally, the cyclic loading path was clear and appropriate for the cyclic loading and unloading calculations.

scholarly journals Mykhailo Dendiuk, Lyubomir Flud, Nazar Semenyshyn Software implementation of the construction of curves short-term strength of wood with biaxial stress state

2020 ◽  
Vol 8 ◽  
pp. 21-26
Author(s):  
Mykhailo Dendiuk ◽  
◽  
Lyubomir Flud ◽  
Nazar Semenyshyn ◽  
◽  
...  
Keyword(s):  
Stress State ◽  
Failure Criteria ◽  
Biaxial Stress ◽  
Term Strength ◽  
Short Term ◽  
Tangential Plane ◽  
Biaxial Stress State ◽  
Short Term Strength ◽  
Cross Platform ◽  
Stress States

This paper is devoted to implementing the algorithm for constructing short-term strength curves of wood with biaxial stress states in the radial-tangential plane of structural symmetry. To implement this algorithm was developed software based on the Qt cross-platform toolkit, which allows to build and analyze short-term strength curves in the cross section of wood. The created program has a possibility to choose one of three failure criteria, a kind of wood, temperature and humidity distribution of lumber. The C++ program code is designed so that you can easily add another type of wood as well as a failure criterion. To display the curves, you can select table or graph mode. Graphs can be fixed on a graphics widget, and new ones can be added to compare to previous ones. Based on the analysis of the constructed curves, the ultimate stress state of the material in partial cases is established. In conclusion about expedient using some criteria to describe the strength characteristics of wood with strong and weak asymmetry of strength limits.

THE USE OF NONLOCAL CRITERIA IN FORECASTING FRACTURE OF QUASI-BRITTLE MATERIAL WITH A HOLE UNDER COMPRESSION

2019 ◽  
Vol 85 (4) ◽  
pp. 50-56
Author(s):  
Sergey V. Suknev
Keyword(s):  
Stress Concentration ◽  
Brittle Fracture ◽  
Fracture Zone ◽  
Large Scale ◽  
Failure Criteria ◽  
Material Specimen ◽  
Fictitious Crack ◽  
Non Local ◽  
The Mean ◽  
Nonlocal Criteria

The study is aimed at the development of the new failure criteria for quasi-brittle materials in conditions of stress concentration. The possibility of using non-local failure criteria for description of the brittle, quasi-brittle and ductile fracture of the materials with notches is analyzed. The general feature of these criteria consists in the introduction of the internal dimension characterizing the structure of the material, which provides the possibility of describing a large-scale effect in conditions of the stress concentration and thereby expand the area of their application compared to traditional criteria though it is limited to the cases of brittle or quasi-brittle fracture with a small pre-ffacture zone. To broaden the scope of their application to quasi-brittle fracture with a developed pre-fracture zone we propose to abandon the hypothesis about the size of the pre-fracture zone as a constant related only to the structure of the material. A number of the new nonlocal criteria, which are the development of the criteria of the mean stress and fictitious crack, are developed, substantiated from the physical standpoint, and proved experimentally. These criteria contain a complex parameter characterizing the size of the pre-fracture zone and taking into account not only the structure, but also the ductile properties of the material, specimen geometry and loading conditions. The expressions for the critical pressure in the problem of tensile crack formation upon compression of the samples of geomaterials with a circular hole are derived. The results of calculations match rather well the experimental data on the destruction of drilled gypsum slabs.

Rough Contact Between Elastically and Geometrically Identical Curved Bodies

1982 ◽  
Vol 49 (2) ◽  
pp. 345-352 ◽  
Author(s):  
M. D. Bryant ◽  
L. M. Keer
Keyword(s):  
Maximum Principle ◽  
Brittle Fracture ◽  
Contact Area ◽  
Yield Criterion ◽  
Failure Criteria ◽  
Tensile Stresses ◽  
Potential Failure ◽  
Elliptical Contact ◽  
Normal And Tangential Loads ◽  
Von Mises

Surface and subsurface stresses and displacements are obtained when two geometrically and elastically identical rough bodies are pressed together by normal and tangential loads. The theories of Cattaneo and Mindlin, who introduce zones of slip and stick within an elliptical contact area, are used. Von Mises yield criterion and maximum principle tensile stresses are used as failure criteria to assess potential failure due to shear or brittle fracture.

The mechanics of two-dimensional cellular materials

1982 ◽  
Vol 382 (1782) ◽  
pp. 25-42 ◽  
Keyword(s):  
Mechanical Properties ◽  
Cell Walls ◽  
Cellular Materials ◽  
Elastic Buckling ◽  
Plastic Collapse ◽  
Two Dimensional ◽  
Linear And Nonlinear ◽  
Nonlinear Elastic

The mechanical properties (linear and nonlinear elastic and plastic) of two-dimensional cellular materials, or honeycombs, are analysed and compared with experiments. The properties are well described in terms of the bending, elastic buckling and plastic collapse of the beams that make up the cell walls.

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