ABSTRACT
The considered case refers to the theoretical example of idealized column with critical slenderness λ= λ0, i.e. critical stress σcr is equal to the yield stress σY. The problem was investigated analytically in Kwasniewski & Ziolkowski (2013) but without consideration of subsequent post-buckling loading and unloading stages. For this case a strut with rectangular cross-section made of elastic-perfectly plastic material has been adopted with the bilinear characteristics of σ−ε and with material data: yield stress σY = 189 MPa,Young modulus E = 63300 MPa, Poisson ratio v = 0.45. The cross-section is rectangular with the following dimensions taken for numerical calculations: width b = 19.98 mm, height h = 5.88 mm, total length l = 195.18 mm.The applied boundary conditions result in column effective slenderness λ= λ0 = 57.49 (σcr = σY). It is assumed that the post-buckling bending results in linear distribution of strains in the column cross-sections, i.e. satisfies classical assumption on planar sections.
