DDA is typically formulated as a work-energy method, and can be derived using the principle of minimum potential energy or by using Hamilton's principle. Once the equations of motion are discretized, a step-wise linear time marching scheme in the Newmark family is used for the solution of the equations of motion. The relation between adjacent blocks is governed by equations of contact interpenetration and accounts for friction.
DDA (a method used to solve dynamic problems) relies on work-energy principles or Hamilton's principle, and uses a step-wise linear time marching scheme from the Newmark family to solve the discretized equations of motion. The interaction between adjacent blocks is governed by equations that account for contact interpenetration and friction.