Study of Mechanical Property of Rock under Uniaxial Cyclic Loading and Unloading

Abstract

Through studying the mechanics, energy, and deformation features of rock under uniaxial cyclic loading and unloading, the findings are as follows: (1) under cyclic loading and unloading, the curve of stress and strain for loading and unloading in every cycle was not superposition reciprocally but formed an acutifoliate hysteresis loop. The distribution of the hysteresis loop became denser with the cycles and moved toward the direction of strain increasing. (2) The area of the hysteresis loop indicated the inner damage degree of rock. And the hysteresis energy accumulated was stronger; the damage of rock was more serious. Furthermore, the hysteresis energy grew linearly along with load, and the hysteresis energy accumulated had a trend exponential growth with cycle continuing. (3) The elasticity modulus grew in the form of logarithm as a whole. In each cycle, elasticity modulus for unloading was greater than that for loading. When it exceeded a certain value, elasticity modulus for reloading was less than elasticity modulus for unloading. (4) The cyclic loading and unloading had a strength impact that was gradually stronger and stronger as the cycle went on the sample of rock.

Elastic-Plastic Threshold and Rational Unloading Level of Rocks

“…Rock mechanics studies have been extensively conducted in China and abroad, which cover a broad range, from uniaxial to triaxial compression, simple to multiple conditions, and single to complex paths [1][2][3][4][5][6]. In triaxial tests, the initial stress level mainly includes the initial confining pressure and the initial axial pressure.…”

Investigating the Damaging Effects of the Cyclic Discharge in the Uni-Axial Compression of <i>Raphia vinifera</i> L. Arecacea

“…In the literature, several research studies ( [8] and [15]) agree that when the ratio is close to 1, this indicates the stability within the material. Conversely, as soon as this coefficient departs from 1, this implies degradation within material until it is completely broken (Figure 10).…”

The Influence of Fracture Strain Energy on the Burst Tendency of Coal Seams and Field Application

“…As a special engineering rock mass, coal bodies typically have poor integrity, low strength, a high degree of fracture development, and random distribution of internal grains and fractures [1]. Coal and rock have been extensively studied within the fields of mechanics and energy [2][3][4][5][6][7][8]. Coal production conditions are affected by several factors including the natural environment, production, and technology, all of which can lead to complex mining conditions.…”