Proposed solution for the ground reaction of non-circular tunnels in an elastic-perfectly plastic rock mass

2020 ◽  
Vol 119 ◽  
pp. 103354 ◽  
Author(s):  
Eugie Kabwe ◽  
Murat Karakus ◽  
Emmanuel K. Chanda
Keyword(s):  
Rock Mass ◽  
Perfectly Plastic ◽  
Plastic Rock ◽  
Elastic Perfectly Plastic

scholarly journals Strain-Softening Analyses of a Circular Bore under the Influence of Axial Stress

2021 ◽  
Vol 11 (17) ◽  
pp. 7937
Author(s):  
Xuechao Dong ◽  
Mingwei Guo ◽  
Shuilin Wang
Keyword(s):  
Rock Mass ◽  
Plane Stress ◽  
Strain Softening ◽  
Hydrostatic Stress ◽  
Axial Stress ◽  
Perfectly Plastic ◽  
Out Of Plane ◽  
Softening Process ◽  
Elastic Perfectly Plastic ◽  
Proper Consideration

Strain-softening analyses were performed around a circular bore in a Mohr–Coulomb rock mass subjected to a hydrostatic stress field in cross section and out-of-plane stress along the axis of the bore. Numerical procedures that simplify the strain-softening process in a step manner were employed, and on the basis of the theoretical solutions of the elastic–brittle–plastic(EBP) medium, the strain-softening results of the displacements, stresses and the plastic zones around the circular bore were obtained. The numerical solution was validated based on the fact that the strain-softening process became EBP when the softening slope was very steep and elastic-perfectly plastic(EP) when the softening slope was near zero. The results illustrated that the stresses and displacements in the rock mass surrounding the bore was affected by axial stress and that a proper consideration of out-of-plane stress is necessary. Moreover, the presented results can be used for the verification of numerical codes.

scholarly journals Non linear elasto-plastic analysis of cylindrical cavity in rock mass using a Hoek-Brown criterion

2015 ◽  
Vol 68 (2) ◽  
pp. 145-152
Author(s):  
Jefferson Tales Simão ◽  
Christianne de Lyra Nogueira
Keyword(s):  
Rock Mass ◽  
Constitutive Model ◽  
Cylindrical Cavity ◽  
Local Level ◽  
Consistency Condition ◽  
Linear Analysis ◽  
Perfectly Plastic ◽  
Computational Implementation ◽  
Non Linear ◽  
Elastic Perfectly Plastic

AbstractThis paper aims to present an elastic, perfectly plastic, constitutive model based on the Hoek-Brown failure criterion and with non-associative plasticity. The objective is to apply the model to the non-linear analysis of geotechnical problems like excavations in rock mass. The computational implementation was carried out with a computational program called ANLOG (Non-Linear Analysis of Geotechnical Problem) system based on a displacement formulation of the finite element method. Due to the non-linear nature of the constitutive model, the study adopts an incremental iterative Newton-Raphson procedure with automatic load increments to guarantee the global level equilibrium. In addition, to guarantee the consistency condition at the local level, the study adopts, for the stress integration, an explicit algorithm with automatic sub-increments of strain. To validate the computational implementation and applicability of the numerical model, the study uses theoretical results to compare with ones obtained with the numerical simulation of cylindrical cavity in rock mass.

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.

Crushing of an Elastic-Perfectly Plastic Ring or Tube Between Two Planes

1987 ◽  
Vol 54 (1) ◽  
pp. 159-164 ◽  
Author(s):  
C. Y. Wang
Keyword(s):  
Plastic Deformation ◽  
Numerical Integration ◽  
Mathematical Problem ◽  
Plastic Ring ◽  
Perfectly Plastic ◽  
Analytical Approximations ◽  
Original Shape ◽  
Thin Ring ◽  
Elastic Perfectly Plastic

A thin ring is crushed between two rigid planes. Due to plastic deformation the ring does not recover its original shape when the compression is removed. For an elastic-perfectly plastic flexural material, the ring undergoes two to five different stages. The mathematical problem is formulated and solved by exact numerical integration and accurate analytical approximations.

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