Improvement of vertex-to-vertex contact processing in two-dimensional DDA

This paper proposes a new critical concept for contact processing in the original two-dimensional discontinuous deformation analysis (DDA). A new critical concept that is inside or outside the reference line is proposed to enhance contact processing in the original DDA. When the vertex P is inside of one reference line, the reference line is shifted to the other edge so that P is now outside. The original rules are applicable only when both vertices are outside or inside of both the possible edges. The new critical concept is a stricter algorithm that remedies the indeterminacy of detecting the candidate reference line for vertex-to-vertex contact in the original DDA. The accuracy and effectiveness of the contact-improved DDA were studied using various numerical examples. The simulation results showed that the proposed method is more accurate and useful compared to original method after contact improvement and can be better applied to models with arbitrary vertex-to-vertex contact states.