Behaviour of Cohesionless Soil Reinforced with Three Dimensional Inclusions Under Plane Strain Conditions

2015 ◽  
Vol 96 (3) ◽  
pp. 223-228 ◽  
Author(s):  
M. Harikumar ◽  
N. Sankar ◽  
S. Chandrakaran
Keyword(s):  
Plane Strain ◽  
Three Dimensional ◽  
Cohesionless Soil

Fundamentals of generalized rigidity matrices for multi-layered media

1983 ◽  
Vol 73 (3) ◽  
pp. 749-763
Author(s):  
Maurice A. Biot
Keyword(s):  
Plane Strain ◽  
Initial Stress ◽  
Three Dimensional ◽  
Layered Media ◽  
Mathematical Structure ◽  
Irreversible Thermodynamics ◽  
Initial Stresses ◽  
General Context ◽  
Viscoelastic Media ◽  
Linear Irreversible Thermodynamics

abstract Rigidity matrices for multi-layered media are derived for isotropic and orthotropic layers by a simple direct procedure which brings to light their fundamental mathematical structure. The method was introduced many years ago by the author in the more general context of dynamics and stability of multi-layers under initial stress. Other earlier results are also briefly recalled such as the derivation of three-dimensional solutions from plane strain modes, the effect of initial stresses, gravity, and couple stresses for thinly laminated layers. The extension of the same mathematical structure and symmetry to viscoelastic media is valid as a consequence of fundamental principles in linear irreversible thermodynamics.

Effects of Crystallographic Texture on Plastic Flow Localization

2007 ◽  
Vol 340-341 ◽  
pp. 211-216
Author(s):  
Mitsutoshi Kuroda
Keyword(s):  
Shear Band ◽  
Plane Strain ◽  
Plastic Flow ◽  
Texture Component ◽  
Three Dimensional ◽  
Cube Texture ◽  
Shear Band Formation ◽  
Flow Localization ◽  
Band Formation ◽  
Plastic Flow Localization

In this study, effects of typical texture components observed in rolled aluminum alloy sheets (i.e. Copper, Brass, S, Cube and Goss texture components) on plastic flow localization are studied. The material response is described by a generalized Taylor-type polycrystal model, in which each grain is characterized in terms of an elastic-viscoplastic continuum slip constitutive relation. First, forming limits of thin sheet set by sheet necking are predicted using a Marciniak–Kuczynski (M–K-) type approach. It is shown that only the Cube texture component yields forming limits higher than that for a random texture in the biaxial stretch range. Next, three-dimensional shear band analyses are performed, using a three-dimensional version of M–K-type model, but the overall deformation mode is restricted to a plane strain state. From this simple model analysis, two important quantities regarding shear band formation are obtained: i.e. the critical strain at the onset of shear banding and the corresponding orientation of shear band. It is concluded that the Cube texture component is said to be a shear band free texture, while some texture components exhibit significantly low resistance to shear band formation. Finally, shear band developments in plane strain pure bending of sheet specimens with the typical textures are studied.

Thermal Stresses in Layered Electrical Assemblies Bonded With Solder

1991 ◽  
Vol 113 (4) ◽  
pp. 350-354 ◽  
Author(s):  
H. S. Morgan
Keyword(s):  
Residual Stresses ◽  
Plane Strain ◽  
3D Model ◽  
Thermal Stresses ◽  
Three Dimensional ◽  
Creep Models ◽  
Strain Model ◽  
Maximum Stresses ◽  
Generalized Plane Strain ◽  
Plane Strain Model

Thermal stresses in a layered electrical assembly joined with solder are computed with plane strain, generalized plane strain, and three-dimensional (3D) finite element models to assess the accuracy of the two-dimensional (2D) modeling assumptions. Cases in which the solder is treated as an elastic and as a creeping material are considered. Comparison of the various solutions shows that, away from the corners, the generalized plane strain model produces residual stresses that are identical to those computed with the 3D model. Although the generalized plane strain model cannot capture corner stresses, the maximum stresses computed with this 2D model are, for the mesh discretization used, within 12 percent of the corner stresses computed with the 3D model when the solder is modeled elastically and within 5 percent when the solder is modeled as a creeping material. Plane strain is not a valid assumption for predicting thermal stresses, especially when creep of the solder is modeled. The effect of cooling rate on the residual stresses computed with creep models is illustrated.

C-Specimen Fracture Toughness Testing: Effect of Side Grooves and η Factor

2003 ◽  
Author(s):  
Y. Kim ◽  
Y. J. Chao ◽  
M. J. Pechersky ◽  
M. J. Morgan
Keyword(s):  
Fracture Toughness ◽  
Plane Strain ◽  
Crack Front ◽  
Testing Effect ◽  
Three Dimensional ◽  
Strain Analysis ◽  
Compact Tension ◽  
Compact Tension Specimen ◽  
J Integral ◽  
Η Factor

Elastic-plastic crack front fields in arc-shaped tension specimens (C-specimens) were analyzed by a three-dimensional finite element method. The effect of side grooves on the ductile fracture behavior was investigated by studying the J-integral distribution, plane-strain constraint parameter, and development of plastic zones and comparing to experimental data. The applicability of the η factor (derived for use with compact tension specimens) for the calculation of J-integral values for the C-specimen was also investigated. The results show that side grooves promote and establish near plane strain conditions at the crack front in sub-size specimens. It was also found that a two-dimensional plane-strain analysis in conjunction with the standard American Society for Testing and Materials (ASTM) tests was sufficient to determine the fracture toughness values from side-grooved C-specimen. The results indicate the η factor for compact tension specimen as specified in the ASTM standards appears to produce reliable results for the calculation of J of C-specimens.

Three-Dimensional Elastic Stress Fields of Finite Thickness Plates with Elliptical Hole

2007 ◽  
Vol 353-358 ◽  
pp. 74-77
Author(s):  
Zheng Yang ◽  
Chong Du Cho ◽  
Ting Ya Su ◽  
Chang Boo Kim ◽  
Hyeon Gyu Beom
Keyword(s):  
Stress Concentration ◽  
Plane Strain ◽  
Plane Stress ◽  
Stress Concentration Factor ◽  
Concentration Factor ◽  
Maximum Stress ◽  
Elastic Stress ◽  
Finite Thickness ◽  
Plate Thickness ◽  
Three Dimensional

Based on detailed three-dimensional finite element analyses, elastic stress and strain field of ellipse major axis end in plates with different thickness and ellipse configurations subjected to uniaxial tension have been investigated. The plate thickness and ellipse configuration have obvious effects on the stress concentration factor, which is higher in finite thickness plates than in plane stress and plane strain cases. The out-of-plane stress constraint factor tends the maximum on the mid-plane and approaches to zero on the free plane. Stress concentration factors distribute ununiformly through the plate thickness, the value and location of maximum stress concentration factor depend on the plate thickness and the ellipse configurations. Both stress concentration factor in the middle plane and the maximum stress concentration factor are greater than that under plane stress or plane strain states, so it is unsafe to suppose a tensioned plate with finite thickness as one undergone plane stress or plane strain. For the sharper notch, the influence of three-dimensional stress state on the SCF must be considered.

An evaluation of simplified techniques for estimating three-dimensional undrained ground movements due to tunnelling in soft soils

1992 ◽  
Vol 29 (1) ◽  
pp. 39-52 ◽  
Author(s):  
R. K. Rowe ◽  
K. M. Lee
Keyword(s):  
Plane Strain ◽  
Deformation Behaviour ◽  
Three Dimensional ◽  
Strain Analysis ◽  
Cumulative Probability ◽  
Element Analysis ◽  
Cross Sectional ◽  
Soft Soils ◽  
Longitudinal Plane ◽  
Stress Changes

A number of simplified approaches have been used by various researchers to estimate the three-dimensional stress changes and ground deformations due to shallow tunnels in soft soils. The effectiveness of these simplified analyses, such as (i) axisymmetric analysis, (ii) longitudinal plane strain analysis, and (iii) empirical cumulative probability distribution approach, has been examined by comparison of results with those from a full three-dimensional elastoplastic finite-element analysis. For tunnels located at shallow depths, axisymmetric analyses are generally found to be unable to predict the correct magnitude of displacement around a tunnel heading. However, the trend of the three-dimensional deformation behaviour near the tunnel heading can be reasonably approximated by the average of the normalized displacement curves predicted by the two axisymmetric assumptions as described in this paper. The three-dimensional distribution of the displacement near the ground surface, on the other hand, can be approximately predicted by the cumulative probability approach, provided that the three empirical parameters required by the equations are reasonably estimated. In this paper, these parameters were estimated from the result of a two-dimensional plane strain cross-sectional analysis. Finally, it was found that modelling of three-dimensional deformations by a longitudinal plane strain analysis did not give good results for the cases examined. Key words : tunnelling, soft ground, analysis.

Three-dimensional stability analysis for slurry-filled trench wall in cohesionless soil

1996 ◽  
Vol 33 (5) ◽  
pp. 798-808 ◽  
Author(s):  
Jiin-Song Tsai ◽  
Jia-Chyi Chang
Keyword(s):  
Stability Analysis ◽  
Stability Problem ◽  
Slip Surface ◽  
Three Dimensional ◽  
Vertical Direction ◽  
Soil Mass ◽  
Cohesionless Soil ◽  
Cohesionless Soils ◽  
Slurry Trench ◽  
The Stability

On the basis of the limiting equilibrium and arching theory, a three-dimensional analysis is proposed for slurry-supported trenches in cohesionless soils. This analytical approach is developed by considering the trench stability problem as a vertical soil cut within a fictitious half-silo with a rough wall surronding. Arching effects are considered not only in the vertical direction but also in the horizontal direction. A shell-shaped slip surface of the sliding soil mass is defined by Mohr-Coulomb criterion. The factor of safety is defines as the ratio of the resisting force induced by slurry pressure to the horizontal force required to maintain the stability of the trench wall. Results of the proposed method have been compared with those of two existing analytical methods for a typical trench stability problem. Key words: stability analysis, slurry trench wall, cohesionless soil.

scholarly journals Cyclic overlay model of p-y curves for laterally loaded monopiles in cohesionless soil

2021 ◽  
Author(s):  
Junnan Song ◽  
Martin Achmus
Keyword(s):  
Cyclic Loading ◽  
Large Diameter ◽  
Three Dimensional ◽  
Element Model ◽  
Offshore Wind ◽  
Cohesionless Soil ◽  
Triaxial Tests ◽  
Cyclic Loads ◽  
Ongoing Research ◽  
Overlay Model

Abstract. The bearing behaviour of large-diameter monopile foundations for offshore wind turbines under lateral cyclic loads in cohesionless soil is an issue of ongoing research. In practice, mostly the p-y approach is applied in the design of monopiles. Recently, modifications of the original p-y approach for monotonic loading stated in the API regulations (API 2014) have been proposed to account for the special bearing behaviour of large-diameter piles with small length-to-diameter ratios (e.g. Thieken et al. 2015, Byrne et al. 2015). However, cyclic loading for horizontally loaded piles predominates the serviceability of the offshore wind converters, and the actual number of load cycles cannot be considered by the cyclic p-y approach of the API regulations. This research is therefore focusing on the effects of cyclic loading on the p-y curves along the pile shaft and aiming to develop a cyclic overlay model to determine the cyclic p-y curves valid for a lateral load with a given number of load cycles. The “Stiffness Degradation Method (SDM)” (Achmus et al. 2009) is applied in a three-dimensional finite element model to determine the effect of the cyclic loading by degrading the secant soil stiffness according to the magnitude of cyclic loading and number of load cycles based on the results of cyclic triaxial tests. Thereby, the numerical simulation results are used to develop a “cyclic overlay model”, i.e. an analytical approach to adapt the monotonic (or static) p-y curve to the number of load cycles. The new model is applied to a reference system and compared to the API approach for cyclic loads.

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