封闭应力方向对巴西圆盘试验影响的数值模拟

NUMERICAL SIMULATION OF INFLUENCE OF LOCKED-IN STRESS DIRECTION ON BRAZILIAN DISC TEST

  • 摘要: 为揭示封闭应力对巴西圆盘应力分布和破裂演化过程的影响,开展不同方向封闭应力对巴西圆盘破裂二维数值模拟研究。将封闭应力的区域等效成一个封闭的包裹体分布在岩体中,探究不同方向封闭应力对圆盘应力分布和裂纹扩展的影响。结果表明,施加封闭应力的部位出现局部应力变化明显高于未施加的区域,随着加载的进行,施加封闭应力区域的局部应力小于周围未施加封闭应力的区域;对比有无封闭应力存在时加载过程中最大米塞斯应力,得出当封闭应力与加载方向夹角为0°时最大,为20.78 MPa;当无封闭应力和封闭应力方向为0°时,圆盘中心起裂,封闭应力方向为30°,60°,90°时,圆盘的裂纹带发生倾斜并出现多条倾斜短裂纹,圆盘未中心起裂。

     

    Abstract: In order to reveal the influence of locked-in stress on the stress distribution and rupture evolution process of Brazilian disc, a two-dimensional numerical simulation of locked-in stress on the rupture process of Brazilian disc in different directions was carried out. The region of locked-in stress is equivalent to a closed inclusion distributed in the rock mass. The disk distribution of locked-in stress in different directions and the formation and propagation process of cracks were investigated. The results show that the change of local stress in the locked-in stress area is significantly higher than that in the non-residual stress area, and the local stress in this area gradually decreases to less than the surrounding stress with the loading process. By comparing the maximum Mise stress in loading process with or without locked-in stress, it is found that the maximum Mise value is 20.78 MPa when the angle between locked-in stress and loading direction is 0°. When there is unlocked in stress and the direction of locked-in stress is 0°, the center of the disk cracks; when the direction of locked in stress is 30°, 60° and 90°, the crack zone of the disk tilts and several short inclined cracks appear, and the disk does not crack at the center.

     

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