In this study, we propose a new scheme of nonlinear analysis for Incheon International Airport Terminal-2 which was opened on January of 2018 for the Olympic Winter Games of PyeongChang in South Korea. The terminal was built by a single layered irregular space frame. It has hard problems for nonlinear analysis geometrically, because of a limitation of personal computer's ability by the number of rigid joints in the roof. Therefore we attempt easier approach to be chosen a center part of the roof instead of the whole structure, and to substitute the other boundary parts as springs. The scheme shows some merits for saving memory and calculation time and so on.