SOME ISSUES IN DISCONTINUOUS DEFORMATION ANALYSIS

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.