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砂土等散粒体在剪切过程中的能量存储及耗散是其宏观力学响应的深层原因,但因量测难度较大而研究较少。将考虑抗转动的接触模型引入离散元软件PFC2D,基于热力学第一定律建立各种能量量测方法,并在平面应变双轴压缩试验中采用该方法统计密实散粒体在剪切过程中的能量演化规律。采取了4种耗散类型,即滑动-滚动(S-R)、滑动-非滚动(S-NR)、非滑动-滚动(NS-R)和非滑动-非滚动(NS-NR)。结果表明:密实散粒体加载时能量耗散以滑动摩擦为主;且小应变加载阶段,外力功主要转化为弹性应变能,但同时也存在均布于试样的耗散能;随着应变的增加,外力功的转化形式逐渐过渡为以耗散能为主,且集中分布在带状区域内;各个加载阶段的摩擦耗散均存在各向异性。
The energy storage and dissipation of sand and other granular materials in the process of shearing are the deep reasons for the macroscopic mechanical response. However, there are few studies on the difficulty due to the difficulty of measurement. The anti-rotation contact model is introduced into the discrete element software PFC2D. Based on the first law of thermodynamics, various energy measurement methods are established. In the plane strain biaxial compression test, this method is used to calculate the energy of dense granular particles in the shearing process Evolutionary law. Four dissipative types were adopted: S-R, S-NR, NS-R and NS-NR. The results show that the energy dissipation is mainly sliding friction when the compact granular material is loaded. In the small strain loading stage, the external force is mainly transformed into the elastic strain energy, but there is also dissipative energy uniformly distributed in the specimen. , The transformation form of external force gradually transitioned to dissipate energy mainly in the banded region, and the frictional dissipation in each loading stage is anisotropic.