Light steel structure;  Portal rigid frame;  stability;  Calculate the length

In view of the shortcomings of the current regulations in the stability design of lightweight portal rigid frame steel structure, the overall stability study in the plane was carried out by the finite element method. The calculation length coefficient of the overall stability of the non-side-shifting rigid frame is proposed, the overall stability of the lightweight portal rigid frame structure under asymmetry is discussed, the influence of the main bending moment on the lightweight portal rigid frame is studied, and the calculation formula of the overall stability in the plane of the lightweight portal rigid frame is given. The research results can be used as a reference for the stable design of lightweight portal rigid frame steel structure.