摘要：This paper presents a modified method of discontinuous deformation analysis （DDA）. In the presentedmethod, open-close iteration may not be needed, small penetration is permitted among blocks, andsprings are added between contacting block pairs only when a penetration takes place. The three contactpatterns （i.e. sliding, locking and opening） in original DDA method are not involved, and the recognitionof these contact patterns and treatment of transformation among patterns are not required either,significantly saving the computing time. In a convex to concave contact, there are two candidate entranceedges which may cause uncertainty. In this case, we propose the angle bisector criterion to determine theentrance edge. The spring stiffness is much larger than Young＇s modulus in the original DDA, however wefind that the correct results can still be obtained when it is much smaller than Young＇s modulus. Finally,the penetrations by using penalty method and augmented Lagrangian method are compared. Penetrationof the latter is 1/4 of the former. The range of spring stiffness for the latter is wider than the former,being 0.01e1 of the former. Both methods can lead to correct contact forces. 2015 Institute of Rock and Soil Mechanics, Chinese Academy of Sciences. Production and hosting byElsevier B.V. All rights reserved.

关键词：discontinuous deformation analysis iteration contact 

单位：School of Mechanics and Engineering Southwest Jiaotong University Chengdu Sichuan 610031 China Yangtze River Scientific Research Institute Wuhan Hubei 430010 China