scholarly journals Parametric stress-strain analysis for upstream slope of the asphaltic concrete core rockfill dams in static state

2021 ◽  
Vol 34 (06) ◽  
pp. 1800-1818
Author(s):  
Shahram Shiravi ◽  
Arash Razmkhah
Keyword(s):  
Shear Stress ◽  
Static Analysis ◽  
Maximum Shear Stress ◽  
Strain Analysis ◽  
Asphaltic Concrete ◽  
Total Stress ◽  
Stress Strain ◽  
Concrete Core ◽  
Static State ◽  
Upstream Slope

In this study, the effects of various geometric parameters of a dam in 2D static analysis of stress-strain on the upstream slope of the asphaltic concrete core rockfill dams were investigated. For this purpose, first the geometric characteristics of a large number of world's dams were collected and assessed, then by geometric modeling of these dams, many numerical models were developed for static analysis using GeoStudio software in eight height classes, three cases of upstream and downstream slopes, three different shape and thickness of the asphaltic concrete core under different Impounding states including "Full Reservoir", "Half full Reservoir", "End of construction and "Rapid Drawdown on a rigid type of foundation. The results of this study demonstrated that in four different construction and impounding states and in three different cases of slopes, Increasing the height parameter, causes increasing the Maximum total stress, Maximum total strain, Shear strain and Maximum shear stress for all construction and impounding states. The Maximum total stress decreased for all operating situations as the upstream slope reduced. According to the obtained results from the static stress-strain analysis, increasing both vertical and inclined asphaltic concrete core thicknesses, leads to decreasing the Maximum shear stress in Full Reservoir state but it increases in other state of impoundment. Moreover, by comparing the displacements related to specified points on the upstream slopes, increasing the height parameter, leads to increasing both horizontal and vertical displacements, the volumetric strain, deviator strain and deviator stress for all impounding conditions. In the following, the additional results were provided along with diagrams for further analysis.

Plastic Stress-Strain Relations

1948 ◽  
Vol 159 (1) ◽  
pp. 95-114 ◽  
Author(s):  
W. M. Shepherd
Keyword(s):  
Shear Stress ◽  
Tensile Stress ◽  
Shear Strain ◽  
Maximum Shear Stress ◽  
The Other ◽  
Plastic Strains ◽  
Stress Strain ◽  
Thin Tube ◽  
Shear Strains ◽  
Comparable Magnitude

The author derives stress-strain relations which are applicable to problems in which the elastic and plastic strains are of comparable magnitude. Two alternative criteria are used, one based on the Mises-Hencky function and the other on the maximum shear stress. Shear stress-shear strain curves are deduced from tensile stress-strain curves and the result is in one case compared with experiment. The problem of a thin tube strained in tension beyond the onset of plasticity and then subjected to an increasing torque is considered, and the tensile and shear strains due to the torque are found. A result relating to the energy lost in plastic straining is obtained.

Critical Plane Search Method for Biaxial and Multiaxial Fatigue Analysis

2016 ◽  
Author(s):  
Kumarswamy Karpanan
Keyword(s):  
Shear Stress ◽  
Stress State ◽  
Strain Amplitude ◽  
Stress Amplitude ◽  
Maximum Shear Stress ◽  
Fatigue Analysis ◽  
Search Method ◽  
Stress Range ◽  
Critical Plane ◽  
Stress Strain

For complex cyclic loadings, stress- or strain-based critical plane search methods are commonly used for fatigue analysis of the structural components. Complex loadings can result in a non-proportional type loading in which it is difficult or impossible to determine the plane with maximum shear stress/strain amplitude. ASME Sec VIII, Div-3 fatigue analysis for non-welded components is a shear stress based fatigue analysis method and, for non-proportional loading, uses the critical plane search method to calculate the plane with maximum shear stress amplitude. For a two-dimensional non-proportional stress state, analytical stress transformation equations can be used to calculate the shear stress or strain amplitude on any plane at a point. The shear stress range on each plane is the difference between the maximum and minimum shear stress. For a three-dimensional stress state, shear stress amplitude calculations are much more complicated because the shear stress is a vector and both magnitude and direction change during the loading cycle. In ASME VIII-3, the maximum shear stress range among all planes, along with the normal stress on the plane, is used to calculate the stress amplitude. This paper presents a method to calculate the shear stress/strain amplitude using 3D transformation equations. This method can be used for any stress- or strain-based critical plane search method. This paper also discusses ASME proportional and non-proportional fatigue analysis methods in detail.

A Method for Uniform Shear Stress-Strain Analysis of Adhesives

1990 ◽  
Vol 18 (3) ◽  
pp. 203 ◽  
Author(s):  
A Wolfenden ◽  
GW Wycherley ◽  
SA Mestan ◽  
I Grabovac
Keyword(s):  
Shear Stress ◽  
Strain Analysis ◽  
Stress Strain ◽  
Uniform Shear

scholarly journals A polynomial approach to determine stress in an elastic body of circular section indented by conformable contact

2006 ◽  
Vol 33 (3) ◽  
pp. 199-212
Author(s):  
J. Hinojosa-Torres ◽  
J.L. Hernandez-Anda
Keyword(s):  
Shear Stress ◽  
Elastic Body ◽  
Biaxial Tension ◽  
Maximum Shear Stress ◽  
Total Stress ◽  
Principal Stresses ◽  
Circular Section ◽  
Free Area ◽  
Polynomial Distribution ◽  
Good Agreement

A polynomial of degree greater than two that describes the indenter concavity shape is proposed. From the proposed polynomial, the gradient of the displacement is derived and combined with that one determined by Timoshenko and Goodier to obtain the polynomial distribution of the pressure in the cross direction of wire. By using the polynomial pressure in the "stress function" proposed by Flamant, a set of equations serving to know the stresses state in the wire section is obtained. To extend the analysis to two opposite indenters, all contributions to total stress are considered, to knowing: the stresses being produced by each one of the indenters; the biaxial tension to balance the free area of pressure. Finally, by using all contributions to total stress and determining the principal stresses, the magnitude of maximum-shear-stress at each point of elastic body it could be obtained. In order to confront the model with the reality, by associating to each point its maximum-shear-stress respective, patterns of lines representing isostresses were obtained; such patterns were compared with a photo-elasticity image, showing a good agreement. .

Delamination in the scoring and folding of paperboard

TAPPI Journal ◽  
2012 ◽  
Vol 11 (1) ◽  
pp. 61-66 ◽  
Author(s):  
DOEUNG D. CHOI ◽  
SERGIY A. LAVRYKOV ◽  
BANDARU V. RAMARAO
Keyword(s):  
Finite Element ◽  
Plane Deformation ◽  
Strain Analysis ◽  
Local Strain ◽  
Uniaxial Stress ◽  
Material Model ◽  
Element Model ◽  
Plastic Behavior ◽  
Stress Strain ◽  
Strain Fields

Delamination between layers occurs during the creasing and subsequent folding of paperboard. Delamination is necessary to provide some stiffness properties, but excessive or uncontrolled delamination can weaken the fold, and therefore needs to be controlled. An understanding of the mechanics of delamination is predicated upon the availability of reliable and properly calibrated simulation tools to predict experimental observations. This paper describes a finite element simulation of paper mechanics applied to the scoring and folding of multi-ply carton board. Our goal was to provide an understanding of the mechanics of these operations and the proper models of elastic and plastic behavior of the material that enable us to simulate the deformation and delamination behavior. Our material model accounted for plasticity and sheet anisotropy in the in-plane and z-direction (ZD) dimensions. We used different ZD stress-strain curves during loading and unloading. Material parameters for in-plane deformation were obtained by fitting uniaxial stress-strain data to Ramberg-Osgood plasticity models and the ZD deformation was modeled using a modified power law. Two-dimensional strain fields resulting from loading board typical of a scoring operation were calculated. The strain field was symmetric in the initial stages, but increasing deformation led to asymmetry and heterogeneity. These regions were precursors to delamination and failure. Delamination of the layers occurred in regions of significant shear strain and resulted primarily from the development of large plastic strains. The model predictions were confirmed by experimental observation of the local strain fields using visual microscopy and linear image strain analysis. The finite element model predicted sheet delamination matching the patterns and effects that were observed in experiments.

Stress-Strain Analysis and Simulation for Estimation of Cutting Forces on the Skin

2015 ◽  
Vol 9 (6) ◽  
pp. 583
Author(s):  
Dario German Buitrago ◽  
Luis Carlos Ruíz ◽  
Olga Lucia Ramos
Keyword(s):  
Cutting Forces ◽  
Strain Analysis ◽  
Stress Strain

scholarly journals Studying the performance of fully encapsulated rock bolts with modified structural elements

2021 ◽  
Author(s):  
Jianhang Chen ◽  
Hongbao Zhao ◽  
Fulian He ◽  
Junwen Zhang ◽  
Kangming Tao
Keyword(s):  
Shear Stress ◽  
Load Transfer ◽  
Maximum Shear Stress ◽  
Coupling Model ◽  
Numerical Approach ◽  
Rock Bolt ◽  
Structural Elements ◽  
Rock Bolts ◽  
Two Stage ◽  
Bolt Diameter

AbstractNumerical simulation is a useful tool in investigating the loading performance of rock bolts. The cable structural elements (cableSELs) in FLAC3D are commonly adopted to simulate rock bolts to solve geotechnical issues. In this study, the bonding performance of the interface between the rock bolt and the grout material was simulated with a two-stage shearing coupling model. Furthermore, the FISH language was used to incorporate this two-stage shear coupling model into FLAC3D to modify the current cableSELs. Comparison was performed between numerical and experimental results to confirm that the numerical approach can properly simulate the loading performance of rock bolts. Based on the modified cableSELs, the influence of the bolt diameter on the performance of rock bolts and the shear stress propagation along the interface between the bolt and the grout were studied. The simulation results indicated that the load transfer capacity of rock bolts rose with the rock bolt diameter apparently. With the bolt diameter increasing, the performance of the rock bolting system was likely to change from the ductile behaviour to the brittle behaviour. Moreover, after the rock bolt was loaded, the position where the maximum shear stress occurred was variable. Specifically, with the continuous loading, it shifted from the rock bolt loaded end to the other end.

Flow and Thermal Fields in a Pendant Droplet Moving on Lyophobic Surface

2010 ◽  
Author(s):  
Basant Singh Sikarwar ◽  
K. Muralidhar ◽  
Sameer Khandekar
Keyword(s):  
Heat Transfer ◽  
Contact Angle ◽  
Reynolds Number ◽  
Shear Stress ◽  
Heat Transfer Coefficient ◽  
Wall Shear Stress ◽  
Transfer Coefficient ◽  
Maximum Shear Stress ◽  
Computational Domain ◽  
Wall Shear

Clusters of liquid drops growing and moving on physically or chemically textured lyophobic surfaces are encountered in drop-wise mode of vapor condensation. As opposed to film-wise condensation, drops permit a large heat transfer coefficient and are hence attractive. However, the temporal sustainability of drop formation on a surface is a challenging task, primarily because the sliding drops eventually leach away the lyophobicity promoter layer. Assuming that there is no chemical reaction between the promoter and the condensing liquid, the wall shear stress (viscous resistance) is the prime parameter for controlling physical leaching. The dynamic shape of individual droplets, as they form and roll/slide on such surfaces, determines the effective shear interaction at the wall. Given a shear stress distribution of an individual droplet, the net effect of droplet ensemble can be determined using the time averaged population density during condensation. In this paper, we solve the Navier-Stokes and the energy equation in three-dimensions on an unstructured tetrahedral grid representing the computational domain corresponding to an isolated pendant droplet sliding on a lyophobic substrate. We correlate the droplet Reynolds number (Re = 10–500, based on droplet hydraulic diameter), contact angle and shape of droplet with wall shear stress and heat transfer coefficient. The simulations presented here are for Prandtl Number (Pr) = 5.8. We see that, both Poiseuille number (Po) and Nusselt number (Nu), increase with increasing the droplet Reynolds number. The maximum shear stress as well as heat transfer occurs at the droplet corners. For a given droplet volume, increasing contact angle decreases the transport coefficients.

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