: Discontinuous Deformation Analysis (DDA) is a technique suitable for investigating fractured rock-mass behavior and geotechnical and structural problems. In the initial implementation of DDA, the 1st order polynomial displacement function was used to approximate the movement of any point in a two-dimensional (2D) domain. As a result, the stress and strain within a block in the model were constant. This study presents the results of an effort to develop a more general approach in which the DDA is implemented with higher order polynomial displacement functions. The higher order displacement functions make accurate modeling of complicated stress and strain fields in blocks possible.
Discontinuous Deformation Analysis (DDA) is suited to investigating fractured rock-mass behavior important to many geotechnical and structural problems. DDA method is the block system version of the finite element method (FEM). It involves a finite element type of mesh where all elements are real isolated blocks, bounded by pre-existing discontinuities (or joints). Although DDA method seems to resemble the distinct element method in that it accounts for joint contact behavior, mathematically it parallels FEM in the following aspects (Shi, 1996)