Elastic coupled local buckling strength of I-shaped steel member in uniform bending

This research aims to theoretically derive a closed-form evaluation formula for the coupled local buckling strength of I-shaped steel members under uniform bending. Power trigonometric functions are used to devise a particular displacement function. Because the function is fast-converging compared to the Fourier function, it is possible for the buckling deflection to be described using only two terms of the trigonometric function. Subsequently, a closed-form evaluation equation is proposed based on the displacement function. An eigenvalue analysis based on the finite element method is then conducted to verify the reliability and effectiveness of the proposed equation.