scholarly journals Mechanical Behavior of Interface between Composite Geomembrane and Permeable Cushion Material

2014 ◽  
Vol 2014 ◽  
pp. 1-9 ◽  
Author(s):  
Haimin Wu ◽  
Yiming Shu ◽  
Linjun Dai ◽  
Zhaoming Teng
Keyword(s):  
Three Dimensions ◽  
Deformation Analysis ◽  
Surface Barrier ◽  
Elastic Model ◽  
Lagrangian Analysis ◽  
Direct Shear Tests ◽  
Perfectly Plastic ◽  
Calculation Results ◽  
Elastic Perfectly Plastic ◽  
Nonlinear Elastic

An accurate description of composite geomembrane-cushion interface behavior is of great importance for stress-deformation analysis and stability assessment of geomembrane surface barrier of rock-fill dam. A series of direct shear tests were conducted to investigate the friction behaviors of interfaces between composite geomembrane and two different permeable cushion materials (crushed stones and polyurethane mixed crushed stones). The shear stress-displacement relationships of the two interfaces show different characteristics and were described by the nonlinear-elastic model and nonlinear-elastic perfectly plastic model, respectively. Then the two models were implemented into the Fast Lagrangian Analysis of Continua in Three Dimensions (FLAC3D) procedure correctly. By verification of a numerical example, numerical calculation results showed a good agreement with the theoretical solutions and test results.

The Method of Design by Analysis for Cylindrical Pressure Vessels with Spherically Dished Head

2019 ◽  
Vol 795 ◽  
pp. 262-267
Author(s):  
Zhen Yu Wang ◽  
Jian Wu ◽  
Ming De Xue ◽  
Shi Yu Li
Keyword(s):  
Internal Pressure ◽  
Shell Theory ◽  
Pressure Vessels ◽  
Design Criteria ◽  
Analysis Method ◽  
Perfectly Plastic ◽  
Elastic Perfectly Plastic ◽  
Nonlinear Elastic ◽  
Theoretical Stress ◽  
Thin Shell Theory

Standards GB 150.3-2011 and JB4732-1995 (Confirmed in 2005) provide design methods for the cylindrical pressure vessels with spherically dished head under internal pressure. It is available for the ratio of the internal pressure p to the allowable stress Sm, p/Sm≥0.002. Engineers desire the design curves for p/Sm<0.002. This paper presents a stress analysis method based on elastic thin shell theory for a spherically dished head jointed to the end or the middle of the cylindrical shell. The design criteria in the current standards are modified. Based on the theoretical stress solution and design criteria, the suitable range of the design curves is extended to p/Sm≥0.001. Nonlinear elastic perfectly-plastic finite element method ensures the reliability of the design curves.

scholarly journals Stress and Deformation Property of Geomembrane Surface Barrier for High Rock-fill Dam

2019 ◽  
Vol 275 ◽  
pp. 03003
Author(s):  
Haimin Wu ◽  
Zhen Zhang ◽  
Yiming Shu
Keyword(s):  
Peripheral Zone ◽  
Three Dimensions ◽  
Surface Barrier ◽  
Test Results ◽  
Rock Fill ◽  
Perfectly Plastic ◽  
Stress And Deformation ◽  
Elastic Perfectly Plastic ◽  
Material Nonlinear ◽  
Nonlinear Elastic

Based on the direct shear test results of interface between a composite geomembrane and cushion material, nonlinear elastic, perfectly plastic model was used to describe the interface behaviors. The interface model was incorporated into the Geogrid element of a fast Lagrange analysis of continua in three dimensions (FLAC3D) procedure through a user-defined program in the FISH. Then a geomembrane surfaced rock-fill dam on thick pervious foundation was numerically analyzed using the incorporated model. The numerical results showed that only small tension deformation can be found in the most area of geomembrane on the dam surface. However, large tension deformation of geomembrane appeared close to the anchorage in the peripheral zone of the barrier. The anchorage structure of geomembrane in this area should be carefully designed to avoid tension failure of geomembrane.

scholarly journals Numerical simulation of hillside mine waste dump construction

2012 ◽  
Vol 65 (4) ◽  
pp. 553-559 ◽  
Author(s):  
Marcílio Baltazar Teixeira ◽  
Christianne de Lyra Nogueira ◽  
Waldyr Lopes de Oliveira Filho
Keyword(s):  
Numerical Simulation ◽  
Mine Waste ◽  
Waste Dump ◽  
The Finite Element Method ◽  
Linear Elastic ◽  
Perfectly Plastic ◽  
Geometric Configurations ◽  
Mine Waste Dump ◽  
Elastic Perfectly Plastic ◽  
Nonlinear Elastic

In activities involving disposal of mine waste in a dump, it is necessary to carry out a preliminary study of the mechanical behavior of both dump and the foundation materials. Due to the complexity of this problem, numerical techniques are essential for providing an approximate answer to the problem. Thus, the finite element method (FEM) was used to evaluate the stress-strain-strength behavior of a hillside waste dump built on a deformable foundation by the ascending method; the results of which are herein presented. The dump material is considered to be Morh-Coulomb nonlinear elastic perfectly plastic while the foundation material is considered to be linear elastic. The numerical simulation of mine waste dump construction is carried out by the "gravity turn on" technique and the dynamic mesh procedure. Different geometric configurations are analyzed and it is concluded that some requirements established by law should be reviewed and refined.

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.

Analytical Solutions of Crack Tip Plasticity Zone Shape for a Semi-Infinite Crack

2003 ◽  
Author(s):  
Peihua Jing ◽  
Tariq Khraishi ◽  
Larissa Gorbatikh
Keyword(s):  
Plane Strain ◽  
Plane Stress ◽  
Analytical Solutions ◽  
Yield Criterion ◽  
Plasticity Zone ◽  
Linear Elastic ◽  
Perfectly Plastic ◽  
Classical Plasticity ◽  
Elastic Perfectly Plastic ◽  
Von Mises

In this work, closed-form analytical solutions for the plasticity zone shape at the lip of a semi-infinite crack are developed. The material is assumed isotropic with a linear elastic-perfectly plastic constitution. The solutions have been developed for the cases of plane stress and plane strain. The three crack modes, mode I, II and III have been considered. Finally, prediction of the plasticity zone extent has been performed for both the Von Mises and Tresca yield criterion. Significant differences have been found between the plane stress and plane strain conditions, as well as between the three crack modes’ solutions. Also, significant differences have been found when compared to classical plasticity zone calculations using the Irwin approach.

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