BUCKLING ANALYSIS OF ORTHOTROPIC STEEL STRIPS BY THE SPLINE FINITE ELEMENT METHOD

Steel strips exhibit orthotropy due to the orientational preference of the crystalline structure in the rolling processes. The influence of the orthotropy on the buckling behavior of steel strips is investigated in this study. On the basis of the small deflection theory and the principle of stationary potential energy for orthotropic thin plates, the computational model of common flatness for pre-buckling deformation is established by the spline finite element method under plastic strain (initial strain). The relationships among the degree of anisotropy, the critical plastic strain and the critical wavelength are formulated. According to the large deflection theory and the virtual work principle, the path of post-buckling of steel strips is obtained by using the spline finite element method. The buckling behavior of center wave, edge wave, composite wave and quarter wave is analyzed under different degrees of orthotropy. The effect of othotropy on pre-buckling critical conditions and post-buckling deformation processes are also evaluated.