The effect of relative rotation at joints on the critical load of axisymmetric and non-sway bending frame made up of laminated members

In present study, the buckling analysis of non-swayand two-story axisymmetric bending frame made up oflaminated members with rectangular sections and throughthicknessvariation of mechanical properties is conducted byemploying stability functions. The ideal members without initialcurvature are subjected to axial compression withouteccentricity. The members of the frame are constructed by theperfect connections of two various metallic plates with the samewidths and different thickness and elasticity modulus,consequently the curvature of the plates at any arbitrary point issame as the curvature of the buckled laminated member at thatpoint. The connection of the members at joints has a relativerotation; therefore the frame has the semi-rigid connections.However results show that changes in thickness, length andmaterials of the layers in heterogeneous members do not affectthe carry over factor, stiffness and modified stiffnesscoefficients, but the critical loads of frames are dependent onmentioned parameters. The ratio of the critical load ofheterogeneous to critical load of homogeneous bending frames isequal to the ratio of equivalent bending rigidity to bendingrigidity of the homogeneous member.