Macro-Meso Analysis of Stress and Strain Fields of Granular Materials

2020 ◽  
pp. 97-136
Author(s):  
Shunying Ji ◽  
Lu Liu
Keyword(s):  
Granular Materials ◽  
Stress And Strain ◽  
Strain Fields

Interfaces Behavior in Glued Granular Materials

2015 ◽  
Vol 665 ◽  
pp. 113-116
Author(s):  
Michele Buonsanti ◽  
Fortunato Ceravolo ◽  
Giovanni Leonardi ◽  
Francesco Scopelliti
Keyword(s):  
Granular Materials ◽  
Structural Integrity ◽  
High Surface ◽  
Volume Element ◽  
Model Specification ◽  
Scale Model ◽  
Critical Conditions ◽  
Stress And Strain ◽  
Strain Fields ◽  
Micro Scale

In this paper a micro-scale model to investigate the structural integrity of a runway surface has been developed. By performing stress analysis on a representative volume element (RVE), our model specification has been focalized on two elementary mixture constituents, two rigid components glued together by asphalt. The analysis is performed under thermo-mechanical actions, as those produced by landing gear impact and variable high surface temperatures. Three different interfaces (rigid to rigid, rigid to soft and soft to soft), three different asphalt density and two different values of surface temperature have been considered in the simulation. Resulting stress and strain fields are compared to define the greater critical conditions and to evaluate the micro-scale structural integrity

Mathematical Model of the Effective Properties of a Fiber Reinforced Composite with a Linearly Graded Transition Zone

2010 ◽  
Vol 38 (4) ◽  
pp. 286-307
Author(s):  
Carey F. Childers
Keyword(s):  
Mathematical Model ◽  
Transition Zone ◽  
Effective Properties ◽  
Local Stress ◽  
Stress And Strain ◽  
Fiber Reinforced ◽  
Strain Fields ◽  
Shear Moduli ◽  
Fiber Reinforced Composite ◽  
Reinforced Composite

Abstract Tires are fabricated using single ply fiber reinforced composite materials, which consist of a set of aligned stiff fibers of steel material embedded in a softer matrix of rubber material. The main goal is to develop a mathematical model to determine the local stress and strain fields for this isotropic fiber and matrix separated by a linearly graded transition zone. This model will then yield expressions for the internal stress and strain fields surrounding a single fiber. The fields will be obtained when radial, axial, and shear loads are applied. The composite is then homogenized to determine its effective mechanical properties—elastic moduli, Poisson ratios, and shear moduli. The model allows for analysis of how composites interact in order to design composites which gain full advantage of their properties.

The stress and strain fields in the neighbourhood of a notch in polyethylene

Polymer ◽  
1989 ◽  
Vol 30 (8) ◽  
pp. 1456-1461 ◽  
Author(s):  
Xue-qin Wang ◽  
Norman Brown
Keyword(s):  
Stress And Strain ◽  
Strain Fields

Endochronic Analysis of Cyclic Elastoplastic Strain Fields in a Notched Plate

1983 ◽  
Vol 50 (4a) ◽  
pp. 789-794 ◽  
Author(s):  
K. C. Valanis ◽  
J. Fan
Keyword(s):  
Residual Stress ◽  
Numerical Scheme ◽  
External Loading ◽  
Stress And Strain ◽  
Elastoplastic Strain ◽  
Residual Stress Field ◽  
Progressive Change ◽  
Strain Fields ◽  
Cyclic Tension ◽  
Cyclic Elastoplastic Strain

In this paper we present an analytical cum-numerical scheme, based on endochronic plasticity and the finite element formalism. The scheme is used to calculate the stress and elastoplastic strain fields in a plate loaded cyclically in its own plane along its outer edges and bearing two symmetrically disposed edge notches. One most important result that stands out is that while the external loading conditions are symmetric and periodic, the histories of stress and strain at the notch tip are neither symmetric nor periodic in character. In cyclic tension ratcheting phenomena at the tip of the notches prevail and a progressive change of the residual stress field at the notch line is shown to occur.

scholarly journals Biomechanical Aspects of Closing Approaches in Postcarotid Endarterectomy

2018 ◽  
Vol 2018 ◽  
pp. 1-10
Author(s):  
Idit Avrahami ◽  
Dafna Raz ◽  
Oranit Bash
Keyword(s):  
Carotid Bifurcation ◽  
Stress And Strain ◽  
Surgery Complications ◽  
Artery Wall ◽  
Strain Fields ◽  
Structure Interaction ◽  
Cerebral Blood Supply ◽  
Patch Angioplasty ◽  
Alternative Approach ◽  
The Common

The carotid bifurcation tends to develop atherosclerotic stenoses which might interfere with cerebral blood supply. In cases of arterial blockage, the common clinical solution is to remove the plaque via carotid endarterectomy (CEA) surgery. Artery closure after surgery using primary closures along the cutting edge might lead to artery narrowing and restrict blood flow. An alternative approach is patch angioplasty which takes longer time and leads to more during-surgery complications. The present study uses numerical methods with fluid-structure interaction (FSI) to explore and compare the two solutions in terms of hemodynamics and stress and strain fields developed in the artery wall.

The influence of crack size on the ductile-brittle transition

1988 ◽  
Vol 415 (1848) ◽  
pp. 197-226 ◽  
Keyword(s):  
Boundary Layer ◽  
Fracture Toughness ◽  
Transition Temperature ◽  
Plane Strain ◽  
Crack Size ◽  
Specimen Geometry ◽  
External Loading ◽  
Stress And Strain ◽  
Strain Fields ◽  
Penny Shaped Crack

Simple criteria for brittle and ductile crack extension are applied to the stress and strain fields adjacent to the tip of a crack. They are applied at a specified distance from the crack tip, which should be related to the material’s microstructure. The basic approach is to examine each criterion and find which is satisfied first, as the external loading is increased; the predicted fracture is classified either brittle or ductile accordingly. The stress and strain fields depend upon temperature, principally through the variation of flow stress σ 0 with temperature and, to avoid excessive computation, a constitutive relation is constructed which allows stresses and strains both to be scaled in terms of σ 0 , so that major computations need to be done only at a reference temperature, for a range of applied loads. For any given crack configuration, the result of the calculation is a theoretical prediction of fracture toughness as a function of temperature. At low temperatures, the fracture toughness is low and rises rapidly with temperature, corresponding to satisfaction of the criterion for brittle failure. Above a transition temperature, T T , the ductile criterion is satisfied first, and the toughness variation thereafter falls slowly as temperature increases, corresponding to failure ‘on the upper shelf’. Both the absolute level of the toughness at a given temperature and the transition temperature T T are sensitive to crack size as well as specimen geometry. Although this is self-evident for cracks of microstructural dimensions, the striking feature of this work is the prediction that substantial sensitivity to size and geometry may well be displayed for cracks as large as 1 cm in materials of significance for major engineering structures. Generally, toughness increases and transition temperature decreases as crack size decreases, but these beneficial effects can be nullified by stress triaxiality. Detailed calculations are performed for a buried crack and an edge crack under conditions of plane strain and for a penny-shaped crack loaded axisymmetrically. The plane strain calculations are supplemented by ‘boundary layer’ calculations, in which the effect of specimen geometry appears through a single parameter. The close agreement of the ‘boundary layer’ calculations with the full specimen calculations offers the prospect of a simple characterization of specimen geometry and loading, without the need for geometry-specific computations. The calculations that are reported are, of course, based upon a particular model, chosen in part for com­putational convenience. Thus, their status is that they display possible trends which may be considered to merit further investigation, both theoretical and experimental.

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