Abstract:Rigid body-spring model was one of discrete analysis models, which could reflect the realistic cracking pattern of continuum material during the discontinuous process from cracking to failure. This paper introduced and programmed the rigid body-spring model for studying the cracking and failure behavior of concrete member, especially realistic crack pattern of concrete member from cracking to failure, based on the summary of existing research result. The division of rigid body element, characteristics of spring element (the constitutive law of concrete applied to spring element), assembly of rigid body and spring element, the constitutive law of rebar, and the interaction between rebar and concrete were determined firstly. After that, the programming on cracking and failure behavior of concrete member using rigid body-spring model was implemented and verified by a shear-failed RC member. The result demonstrated that the programming could exactly reflect the realistic crack pattern of the member from cracking to failure.