An Improved Discontinuous Deformation Analysis to Solve Numerical Creep Problem in Shear Direction

Discontinuous deformation analysis (DDA) has been widely accepted recently for both static and dynamic problems. When studying block sliding cases, an unphysical phenomenon “numerical creep” (an additional small and finite sliding displacement in each step) yet may be observed. The accumulated creep displacement brings error to the stability and runout distance analysis. Therefore, a modification for DDA is proposed to overcome this numerical creep. The contact evolving in a sliding block case is first investigated and the cause to the numerical creep is deliberately illustrated. Then a modified open-close iteration (OCI) process is proposed to avoid such unphysical phenomenon, in which a new shear force evaluation method is introduced for the locked contacts that transformed from sliding state. Subsequently, the improved DDA with the modified OCI is checked by several block sliding examples under gravity and time-dependent dynamic forces. The comparing results suggest that the simulating accuracy of DDA is significantly improved. Highlights Illustrated reason of the so-called “numerical creep” in Discontinuous Deformation Analysis (DDA). Improved DDA with modified open-close iteration (OCI) that avoids the numerical creep. Verified improved DDA through cases about block stability and sliding.