This study investigated characteristics of buckling load and effective buckling length by member rigidity of dome-typed space frame which was sensitive to initial conditions. A critical point and a buckling load were computed by analyzing the eigenvalues and determinants of the tangential stiffness matrix. The hexagonal pyramid model and star dome were selected for the case study in order to examine the nodal buckling and member buckling in accordance with member rigidity. From the numerical results, an effective buckling length factor of adopted models was bigger than that of Euler buckling for the case of fixed boundary. These numerical models indicated that the influence of nodal buckling was greater than that of member buckling as member rigidity was higher. Besides, there was a tendency that the bifurcation appeared on the equilibrium path before limit point in the member buckling model.

탄성 및 비탄성좌굴 고유치해석법을 이용하여 강절프레임의 보-기둥부재의 유효좌굴길이를 산정하는 개선된 방법을 제시한다. 이를 위하여 먼저 설계기준에 제시된 압축재의 내하력 곡선식으로부터 접선계수이론(tangent modulus theory)에 근거하여 세장비-접선계수(tangent modulus), 응력-변형률 곡선식을 유도한다. 이때 안정함수를 이용하여 보-기둥요소의 접선강성행렬을 얻고, 비탄성 좌굴 고유치해석법을 제시하며 이를 이용하여 유효좌굴길이를 산정하는 방법을 제시한다. 해석예제를 통하여 강절프레임에 탄성 및 비탄성좌굴해석법에 의한 유효좌굴길이 비교결과를 제시하고, 매개변수 연구 결과를 제시한다.

This study investigated characteristics of buckling load and effective buckling length by member rigidity of dome-typed space frame which was sensitive to initial conditions. A critical point and a buckling load were computed by analyzing the eigenvalues and determinants of the tangential stiffness matrix. The hexagonal pyramid model and star dome were selected for the case study in order to examine the nodal buckling and member buckling in accordance with member rigidity.