A two-surface plasticity theory and its application to multiaxial loading

1987 ◽  
Vol 69 (1-4) ◽  
pp. 43-57 ◽  
Author(s):  
W. Y. Lu ◽  
Z. M. Mohamed
2016 ◽  
Vol 53 (4) ◽  
pp. 646-658 ◽  
Author(s):  
Qingsheng Chen ◽  
Buddhima Indraratna ◽  
John P. Carter ◽  
Sanjay Nimbalkar

In this paper, a simple but comprehensive cyclic stress–strain model that incorporates particle breakage for granular soils including ballast and rockfill has been proposed on the basis of bounding surface plasticity theory within a critical state framework. Particle breakage and its effects are captured by a critical state line that is translated in voids ratio–stress space according to the dissipated energy (plastic work), through a hyperbolic function. A comprehensive equation related to particle breakage is proposed for the stress–dilatancy relationship to capture the complex dilatancy of granular soils. By extending Masing’s rule to bounding surface plasticity theory and introducing a generalized homological centre, a combined isotropic–kinematic hardening rule and a mapping rule have been established to simulate more realistically the response of gravelly soils under cyclic loading. The applicability and accuracy of this model are demonstrated by comparing its predictions with experimental results for different types of granular soils, including rockfill, under both monotonic and cyclic loading conditions. This study shows that the model can capture the characteristic features of coarse granular soils under complex loading paths.


2017 ◽  
Vol 62 (4) ◽  
pp. 617-634 ◽  
Author(s):  
A. Esmaeili ◽  
P. Steinmann ◽  
A. Javili

1975 ◽  
Vol 42 (3) ◽  
pp. 641-646 ◽  
Author(s):  
R. D. Krieg

A plasticity theory is presented using the usual concept of a loading surface which moves and isotropically grows, but in addition uses a “limit surface” which grows and moves independently and encloses the loading surface. The plastic stiffness is a function of the distance between the surfaces at the loading point. Characteristics of the theory are a smoother transition between elastic and plastic regions on loading, an inherent Bauschinger effect, and more latitude on the description of hardening characteristics than the traditional methods used in structural codes. The full capability of the theory requires a memory of three vectors and three scalars, while some of the foregoing characteristics can be retained with only two vectors, the same as a traditional kinematic hardening model. The multiaxial theory is presented, particularized, specialized to uniaxial stress and the equations solved. The theory is compared to uniaxial stress experimental results.


1997 ◽  
Vol 119 (1) ◽  
pp. 20-25 ◽  
Author(s):  
Wei Jiang

This paper obtains a closed-form general solution to the two-surface plasticity theory for linear stress paths. The simple two-surface model is discussed first. It is shown that according to this model, the response of the material stabilizes immediately during the first loading cycle. That is, the memory surface reaches its maximum size with a radius equal to the maximum effective stress and then remains unchanged thereafter, while the yield center translates along a line parallel to the stress path, thus always leading to a constant plastic strain growth rate. As a result, the model predicts that under any cyclic linear loading conditions, the material response can always be ratchetting, with no possibility of shakedown of any kinds, which violates those aspects of material behavior that are generally deemed essential in constitutive modeling. The general two-surface theory is also discussed in this paper, and some comments are made.


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