Analytical model of interaction between hexagonal wire mesh and silty sand backfill

2001 ◽  
Vol 38 (4) ◽  
pp. 782-795 ◽  
Author(s):  
D T Bergado ◽  
P Voottipruex ◽  
A Srikongsri ◽  
C Teerawattanasuk
Keyword(s):  
Analytical Model ◽  
Relative Displacement ◽  
Wire Mesh ◽  
Silty Sand ◽  
Hyperbolic Function ◽  
Friction Resistance ◽  
Pullout Resistance ◽  
Mesh Reinforcement ◽  
Perfectly Plastic ◽  
Elastic Perfectly Plastic

The interaction behavior between hexagonal wire mesh and silty sand backfill can be evaluated from pullout tests. The pullout resistance of the hexagonal wire mesh reinforcement consists of two components, namely friction resistance and passive bearing resistance. The friction resistance – relative displacement relationship of a hexagonal wire mesh can be simulated by a linear elastic – perfectly plastic model. The passive bearing resistance of an individual bearing member can be modelled by a hyperbolic function. The friction resistances for galvanized and PVC-coated hexagonal wire mesh were 25 and 21%, respectively, of the total pullout resistance. A new analytical model for predicting the pullout resistance of hexagonal wire mesh reinforcement has been proposed. The proposed solution can estimate the maximum pullout force at different reinforcement levels from observed horizontal movement of a hexagonal wire mesh reinforcement.Key words: hexagonal wire mesh, necking phenomena, bearing resistance, analytical model, pullout box, bearing resistance.

Junction Growth and Energy Dissipation at the Very Early Stage of Elastic-Plastic Spherical Contact Fretting

2009 ◽  
Vol 131 (3) ◽  
Author(s):  
A. Ovcharenko ◽  
I. Etsion
Keyword(s):  
Energy Dissipation ◽  
Friction Force ◽  
Contact Area ◽  
Early Stage ◽  
Static Friction ◽  
Relative Displacement ◽  
Elastic Plastic ◽  
Perfectly Plastic ◽  
Direct Measurements ◽  
Elastic Perfectly Plastic

The contact area, friction force, and relative displacement evolution at the very early stage of fretting are investigated experimentally. Copper and steel spheres of various diameters are loaded against a hard sapphire flat by a range of normal loads deep into the elastic-plastic regime of deformation. A reciprocating tangential loading is then applied with a maximum loading below the static friction to avoid gross slip. Real-time and in situ direct measurements of the contact area, along with accurate measurements of the friction force and relative displacement, reveal substantial junction growth and energy dissipation mainly in the first loading cycle. The so-called “slip amplitude” is found to be attributed to residual tangential plastic deformation rather than to interfacial slip. Elastic shake-down is observed for the 2.5% hardening steel spheres while plastic shake-down is observed in the case of the elastic perfectly-plastic copper spheres.

Interaction Between Hexagonal Wire Mesh Reinforcement and Silty Sand Backfill

2001 ◽  
Vol 24 (1) ◽  
pp. 23 ◽  
Author(s):  
RC Chaney ◽  
KR Demars ◽  
DT Bergado ◽  
C Teerawattanasuk ◽  
T Wongsawanon ◽  
...  
Keyword(s):  
Wire Mesh ◽  
Silty Sand ◽  
Mesh Reinforcement

Very Early Stage of Elastic-Plastic Spherical Contact Fretting

2009 ◽  
Author(s):  
Andrey Ovcharenko ◽  
Izhak Etsion
Keyword(s):  
Friction Force ◽  
Contact Area ◽  
Early Stage ◽  
Static Friction ◽  
Relative Displacement ◽  
Elastic Plastic ◽  
Perfectly Plastic ◽  
Direct Measurements ◽  
Elastic Perfectly Plastic

The contact area, friction force and relative displacement evolution at the very early stage of fretting are investigated experimentally. Copper and steel spheres of various diameters are loaded against a hard sapphire flat by a range of normal loads deep into the elastic-plastic regime of deformation. A reciprocating tangential loading is then applied with a maximum loading below the static friction to avoid gross slip. Real-time and in situ direct measurements of the contact area, along with accurate measurements of the friction force and relative displacement, reveal substantial junction growth and energy dissipation mainly in the first loading cycle. The so called “slip amplitude” is found to be attributed to residual tangential plastic deformation rather than to interfacial slip. Elastic shake-down is observed for the 2.5% hardening steel spheres while plastic shake-down is observed in the case of the elastic perfectly plastic copper spheres.

Analytical Modeling of Hydraulically Expanded Tube-To-Tubesheet Joints

2008 ◽  
Vol 131 (1) ◽  
Author(s):  
Nor Eddine Laghzale ◽  
Abdel-Hakim Bouzid
Keyword(s):  
Contact Pressure ◽  
Analytical Model ◽  
Plastic Material ◽  
Material Behavior ◽  
Initial Contact ◽  
Expansion Process ◽  
Element Analysis ◽  
Elastoplastic Behavior ◽  
Perfectly Plastic ◽  
Elastic Perfectly Plastic

The loss of the initial tightness during service is one of the major causes of failure of tube-to-tubesheet joints. The initial residual contact pressure and its variation during the lifetime of the joint are among the parameters to blame. A reliable assessment of the initial contact pressure value requires accurate and rigorous modeling of the elastoplastic behavior of the tube and the tubesheet during the expansion process. This paper deals with the development of a new analytical model used to accurately predict the residual contact pressure resulting from a hydraulic expansion process. The analytical model is based on the elastic perfectly plastic material behavior of the tube and the tubesheet and the interaction between these two elements of the expanded joint. The model results have been compared and validated with those of the more accurate finite element analysis models. Additional comparisons have been made with existing methods.

Analytical and numerical modeling of pullout capacity and interaction between hexagonal wire mesh and silty sand backfill under an in-soil pullout test

2003 ◽  
Vol 40 (5) ◽  
pp. 886-899 ◽  
Author(s):  
Chairat Teerawattanasuk ◽  
Dennes T Bergado ◽  
Warat Kongkitkul
Keyword(s):  
Numerical Modeling ◽  
Analytical Modeling ◽  
Pullout Test ◽  
Wire Mesh ◽  
Silty Sand ◽  
Lagrangian Analysis ◽  
Interaction Coefficients ◽  
Pullout Resistance ◽  
Pullout Tests ◽  
Clamping System

During the pullout test, the pullout clamping system was modified and installed inside the pullout box with confinement from the fill material, hereinafter called the in-soil pullout test, which significantly reduced the necking phenomenon and the displacements mobilized during the pullout test. Subsequently, an analytical model was developed to predict the in-soil pullout resistance. In addition, a numerical modeling analysis, under the three-dimensional stress field conditions using the FLAC3D (fast Lagrangian analysis continua) program, was carried out to simulate the behavior of in-soil pullout tests. The laboratory in-soil pullout test results were then compared with the corresponding data obtained from the analytical and numerical modeling methods. The in-soil pullout resistance was greater than the corresponding result from previous pullout tests wherein the clamping system was conventionally installed outside the pullout box. The predicted pullout resistance results from FLAC3D agreed reasonably with the results from laboratory tests and with the results from the analytical modeling. The interaction coefficients, R, applied in the finite difference modeling of in-soil pullout tests were 0.90 and 0.65 for zinc-coated and polyvinyl chloride (PVC) coated hexagonal wire meshes, respectively. The predicted and measured pullout resistance of zinc-coated hexagonal wire mesh is approximately 20% greater than that of PVC-coated hexagonal wire mesh at the same applied normal pressure, because of the higher stiffness, EA, and higher shear stiffness, ks, of the zinc-coated mesh.Key words: hexagonal wire mesh, in-soil pullout test, pullout resistance, analytical modeling, numerical modeling.

scholarly journals A FEM analysis of the settlement of a tall building situated on loess subsoil

2020 ◽  
Vol 10 (1) ◽  
pp. 519-526
Author(s):  
Krzysztof Nepelski
Keyword(s):  
Fem Analysis ◽  
Actual Process ◽  
Linear Elastic ◽  
Perfectly Plastic ◽  
Modified Cam Clay ◽  
Linear Behaviour ◽  
Subsequent Calculation ◽  
Elastic Perfectly Plastic ◽  
Subsoil Model ◽  
Storey Building

AbstractIn order to correctly model the behaviour of a building under load, it is necessary to take into account the displacement of the subsoil under the foundations. The subsoil is a material with typically non-linear behaviour. This paper presents an example of the modelling of a tall, 14-storey, building located in Lublin. The building was constructed on loess subsoil, with the use of a base slab. The subsoil lying directly beneath the foundations was described using the Modified Cam-Clay model, while the linear elastic perfectly plastic model with the Coulomb-Mohr failure criterion was used for the deeper subsoil. The parameters of the subsoil model were derived on the basis of the results of CPT soundings and laboratory oedometer tests. In numerical FEM analyses, the floors of the building were added in subsequent calculation steps, simulating the actual process of building construction. The results of the calculations involved the displacements taken in the subsequent calculation steps, which were compared with the displacements of 14 geodetic benchmarks placed in the slab.

Strength envelope of granular soil stabilized by multi-axial geogrid in large triaxial tests

2020 ◽  
Vol 57 (3) ◽  
pp. 448-452 ◽  
Author(s):  
A.S. Lees ◽  
J. Clausen
Keyword(s):  
Triaxial Compression ◽  
Triaxial Tests ◽  
Compression Tests ◽  
Failure Envelope ◽  
Element Analysis ◽  
Linear Elastic ◽  
Perfectly Plastic ◽  
Elastic Perfectly Plastic ◽  
Triaxial Compression Tests ◽  
Properties Of Soil

Conventional methods of characterizing the mechanical properties of soil and geogrid separately are not suited to multi-axial stabilizing geogrid that depends critically on the interaction between soil particles and geogrid. This has been overcome by testing the soil and geogrid product together as one composite material in large specimen triaxial compression tests and fitting a nonlinear failure envelope to the peak failure states. As such, the performance of stabilizing, multi-axial geogrid can be characterized in a measurable way. The failure envelope was adopted in a linear elastic – perfectly plastic constitutive model and implemented into finite element analysis, incorporating a linear variation of enhanced strength with distance from the geogrid plane. This was shown to produce reasonably accurate simulations of triaxial compression tests of both stabilized and nonstabilized specimens at all the confining stresses tested with one set of input parameters for the failure envelope and its variation with distance from the geogrid plane.

On the Conditions to Prevent Plastic Shakedown of Structures: Part I—Theory

1993 ◽  
Vol 60 (1) ◽  
pp. 15-19 ◽  
Author(s):  
Castrenze Polizzotto
Keyword(s):  
Mechanical Load ◽  
Plastic Material ◽  
Perfectly Plastic ◽  
Shakedown Theory ◽  
Elastic Perfectly Plastic ◽  
Plastic Shakedown ◽  
Steady Load

For a structure of elastic perfectly plastic material subjected to a given cyclic (mechanical and/or kinematical) load and to a steady (mechanical) load, the conditions are established in which plastic shakedown cannot occur whatever the steady load, and thus the structure is safe against the alternating plasticity collapse. Static and kinematic theorems, analogous to those of classical shakedown theory, are presented.

Elasto-Plastic Coupled Temperature-Displacement Finite Element Analysis of Two-Dimensional Rolling-Sliding Contact With a Translating Heat Source

1991 ◽  
Vol 113 (1) ◽  
pp. 93-101 ◽  
Author(s):  
S. M. Kulkarni ◽  
C. A. Rubin ◽  
G. T. Hahn
Keyword(s):  
Finite Element ◽  
Half Space ◽  
Plastic Material ◽  
Element Model ◽  
Rolling Contact ◽  
Two Dimensional ◽  
Element Analysis ◽  
Element Mesh ◽  
Perfectly Plastic ◽  
Elastic Perfectly Plastic

The present paper, describes a transient translating elasto-plastic thermo-mechanical finite element model to study 2-D frictional rolling contact. Frictional two-dimensional contact is simulated by repeatedly translating a non-uniform thermo-mechanical distribution across the surface of an elasto-plastic half space. The half space is represented by a two dimensional finite element mesh with appropriate boundaries. Calculations are for an elastic-perfectly plastic material and the selected thermo-physical properties are assumed to be temperature independent. The paper presents temperature variations, stress and plastic strain distributions and deformations. Residual tensile stresses are observed. The magnitude and depth of these stresses depends on 1) the temperature gradients and 2) the magnitudes of the normal and tangential tractions.

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