This paper investigates the characteristics of unstable behaviour and critical buckling load by joint rigidity of framed large spatial structures which are sensitive to initial conditions. To distinguish the stable from the unstable, a singular point on equilibrium path and a critical buckling level are computed by the eigenvalues and determinants of the tangential stiffness matrix. For the case study, a two-free node example and a folded plate typed long span example with 325 nodes are adopted, and these adopted examples' nonlinear analysis and unstable characteristics are analyzed. The numerical results in the case of the two-free node example indicate that as the influence of snap-through is bigger; that of bifurcation buckling is lower than that of the joint rigidity as the influence of snap-through is lower. Besides, when the rigidity decreases, the critical buckling load ratio increases. These results are similar to those of the folded-typed long span example. When the buckling load ratio is 0.6 or less, the rigidity greatly increases.

 Abstract  1. 서 론  2. 비선형평형경로와 불안정점  3. 절점강성에 따른 불안정 현상  4. 수치해석 예제   4.1 완전형상 모델   4.2 초기형상불완전 모델   4.3 절점강성을 고려한 해석 결과  5. 결 론  감사의 글  References

• 손수덕(한국기술교육대학교 건축공학부 연구교수, 공학박사) | Shon, Su-Deok
• 이승재( 한국기술교육대학교 건축공학부 교수, 공학박사) | 이승재
• 이동우( ㈜아이스트 대표이사, 공학박사) | 이동우
• 김승덕( 세명대학교 건축공학과 정교수, 공학박사) | 김승덕