非连续变形分析的若干问题

SOME ISSUES IN DISCONTINUOUS DEFORMATION ANALYSIS

  • 摘要: 基于加法分解及其线性化后的位移增量表达式在更新块体构型时,常导致常规非连续变形分析块体应变计算精度低、块体体积虚假膨胀。根据原始DDA位移模式,分析了该位移模式中因对转?增量1阶近似导致的块体体积自由膨胀;应变分量增量直接叠加导致的块体应变场畸变;以及采用加法分解线性化后的位移增量公式推导块体加速度表达式导致的忽略块体转动时的离心力与科氏力。数值算例表明,原始DDA的位移模式直接导致块体体积自由膨胀、块体内应变场畸变以及忽略了块体转动时离心力与科氏力产生的应变。

     

    Abstract: Updating block configuration based on additive decomposition and its linearized expression of displacement increment lead to the low calculation accuracy of the original discontinuous deformation analysis (DDA) and the false volume expansion. Based on the displacement formulation of the original DDA, the false volume expansion caused by the first order approximation of rotation angle, the strain distortion caused by the direct addition of the incremental strain components, and the neglect of centrifugal force and Coriolis force caused by the derivation of acceleration expression of the block by using the incremental displacement formula after linearization were investigated. The numerical examples show that the displacement formulation of the original DDA directly results in the false volume expansion, the strain distortion and the neglect of the strains produced by the centrifugal force and Coriolis force when the block rotates.

     

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