Effect of Friction and Strength Properties of the Medium on Shear Band Formation in Thrust Structures

Stefanov, Yu. P.; Tataurova, A. A.

doi:10.1134/s1029959919060031

Cited by 10 publications

(1 citation statement)

References 25 publications

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“…We applied the non-associated plastic flow law with the Mises–Schleicher yield criterion (Nikolaevsky’s model) [ 62 , 63 , 80 ] to describe stress relaxation and accumulation of inelastic strains in the cement stone. This model is widely used for natural and artificial brittle materials [ 81 , 82 ]. The effect of pore pressure in the volume of a discrete element that simulates a cement stone on its inelastic mechanical behavior is taken into account using a modified formulation of the Mises–Schleicher yield criterion (Equation (10)):

where α is the internal friction coefficient, Y is cohesion (yield stress under simple shear loading), and

is the equivalent (Mises) stress.…”

Section: Methodsmentioning

confidence: 99%

Nonlinear Mechanical Effect of Free Water on the Dynamic Compressive Strength and Fracture of High-Strength Concrete

Shilko

Konovalenko

2021

Materials

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It is well-known that the effect of interstitial fluid on the fracture pattern and strength of saturated high-strength concrete is determined by qualitatively different mechanisms at quasi-static and high strain rate loading. This paper shows that the intermediate range of strain rates (10−4 s−1 < ε˙ < 100 s−1) is also characterized by the presence of a peculiar mechanism of interstitial water effect on the concrete fracture and compressive strength. Using computer simulations, we have shown that such a mechanism is the competition of two oppositely directed processes: deformation of the pore space, which leads to an increase in pore pressure; and pore fluid flow. The balance of these processes can be effectively characterized by the Darcy number, which generalizes the notion of strain rate to fluid-saturated material. We have found that the dependence of the compressive strength of high-strength concrete on the Darcy number is a decreasing sigmoid function. The parameters of this function are determined by both low-scale (capillary) and large-scale (microscopic) pore subsystems in a concrete matrix. The capillary pore network determines the phenomenon of strain-rate sensitivity of fluid-saturated concrete and logistic form of the dependence of compressive strength on strain rate. Microporosity controls the actual boundary of the quasi-static loading regime for fluid-saturated samples and determines localized fracture patterns. The results of the study are relevant to the design of special-purpose concretes, as well as the assessment of the limits of safe impacts on concrete structural elements.

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