A non-linear elastic/perfectly plastic analysis for plane strain undrained expansion tests

Géotechnique ◽  
1999 ◽  
Vol 49 (1) ◽  
pp. 133-141 ◽  
Author(s):  
M. D. Bolton ◽  
R. W. Whittle
Author(s):  
Peihua Jing ◽  
Tariq Khraishi ◽  
Larissa Gorbatikh

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.


2019 ◽  
Vol 92 ◽  
pp. 16014
Author(s):  
Franz Tschuchnigg ◽  
Gertraud Medicus ◽  
Barbara Schneider-Muntau

The results of slope stability analysis are not unique. Different factors of safety are obtained investigating the same slope. The differences result from different constitutive models including different failure surfaces. In this contribution, different strength reduction techniques for two different constitutive models (linear elastic - perfectly plastic model using a Mohr-Coulomb failure criterion and barodesy) have been investigated on slope stability calculations for two different slope inclinations. The parameters for Mohr – Coulomb are calibrated on peak states of element tests simulated with barodesy for different void ratios. For both slopes the predictions of the factors of safety are higher with barodesy than with Mohr-Coulomb. The difference is to some extend explained by the different shapes of failure surfaces and thus different values for peak strength under plane strain conditions. The plane strain predictions of Mohr-Coulomb are conservative compared to barodesy, where the failure surface coincides with Matsuoka-Nakai.


2020 ◽  
Vol 10 (1) ◽  
pp. 519-526
Author(s):  
Krzysztof Nepelski

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.


2020 ◽  
Vol 57 (3) ◽  
pp. 448-452 ◽  
Author(s):  
A.S. Lees ◽  
J. Clausen

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.


1958 ◽  
Vol 25 (2) ◽  
pp. 239-242
Author(s):  
D. R. Bland ◽  
P. M. Naghdi

Abstract This paper is concerned with a compressible elastic-plastic wedge of an included angle β < π/2 in the state of plane strain. The solution, deduced for an isotropic nonwork-hardening material, employs Tresca’s yield criterion and the associated flow rules. By means of a numerical example the solution is compared with that of an incompressible elastic-plastic wedge in one case (β = π/4) for various positions of the elastic-plastic boundary.


1957 ◽  
Vol 24 (1) ◽  
pp. 98-104
Author(s):  
P. M. Naghdi

Abstract An elastic, perfectly plastic wedge of an incompressible isotropic material in the state of plane strain is considered, where the stress-strain relations of Prandtl-Reuss are employed in the plastic domain. For a wedge (with an included angle β) subjected to a uniform normal pressure on one boundary, the complete solution is obtained which is valid in the range 0 < β < π/2; this latter limitation is due to the character of the initial yield which depends on the magnitude of β. Numerical results for stresses and displacements are given in one case (β = π/4) for various positions of the elastic-plastic boundary.


Author(s):  
Jun Shen ◽  
Heng Peng ◽  
Liping Wan ◽  
Yanfang Tang ◽  
Yinghua Liu

In the past, shakedown evaluation was usually based on the elastic method that the sum of the primary and secondary stress should be limited to 3Sm or the simplified elastic-plastic analysis method. The elastic method is just an approximate analysis, and the rigorous evaluation of shakedown normally requires an elastic-plastic analysis. In this paper, using an elastic perfectly plastic material model, the shakedown analysis was performed by a series of elastic-plastic analyses. Taking a shell with a nozzle subjected to parameterized temperature loads as an example, the impact of temperature change on the shakedown load was discussed and the shakedown loads of this structure at different temperature change rates were also obtained. This study can provide helpful references for engineering design.


2005 ◽  
Vol 40 (3) ◽  
pp. 237-244 ◽  
Author(s):  
G Härkegärd ◽  
A Wormsen

This is the first paper of two that deal with the non-linear analysis of shallow cracks. Simple formulae are given for estimating the J integral for a power-hardening elastic-plastic solid. The proposed equation for estimating J makes use of the linear elastic and the fully plastic solution to interpolate over the entire range from small- to large-scale yielding. The elastic geometry factor is obtained by means of the stress intensity factor. In the fully plastic formulation, the plastic geometry factors are obtained by considering a pure power-hardening solid, which reduces at one limit to an incompressible linear elastic solid, and at the other to a perfectly plastic solid. The solutions are given for three basic configurations: a double-edge-cracked plate under tension and bending; a notched plate under tension with a crack at the root of the notch; a single-edge-cracked plate under bending. Both force control and displacement control are considered. The accuracy of the formulae is assessed using the finite element calculations in Part 2.


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