Calculation of in-plane stability coefficient for lightweight portal rigid frames

Portal rigid frame;  stability;  variable section members;  Calculate the length;  Critical load

According to the limitations of the current norms or regulations on the stability coefficient value in the design of lightweight portal rigid frame, the overall analysis of the elastic stability in the plane of the portal rigid frame is carried out by the finite element method, and the calculated length coefficient of the obtained variable-section column in the rigid frame plane is not limited by the structural form and load conditions of the rigid frame in the traditional design. Using the concept of equivalent rotational stiffness, the conversion length coefficient of wedge beam in the plane of the rigid frame is discussed, and the change relationship between the conversion length coefficient and the geometric dimensions and internal forces of variable section members is pointed out on the basis of a large number of example analysis, for the reference of structural designers.