Rigid body rotation and block internal discretization in DDA analysis

In the original formulation of DDA by Shi, a linear displacement function term is used. This has the limitations of uncontrolled block and stress distortion due to rigid body rotation. In the present paper, the authors propose a new iterative method which can avoid the distortion due to the rotation even when the rotation or number of time-step is large. Furthermore, the authors propose a simple internal discretization scheme which is applicable for both concave and convex polygon which is particularly important for a large block. The stress and strain distribution with a large block can be obtained with ease under this scheme. The numerical examples as shown have demonstrated the advantages of the present proposal in DDA analysis.