Analysis of Mechanical Properties of Steel Tube Crossing Frame for Power Transmission Project

In this study, compared with traditional scaffolds, the arrangement and structural dimensions of steel tubular crossing frames used in transmission engineering are significantly different, making it difficult to efficiently and accurately evaluate their structural stability using existing specifications and conventional methods. Therefore, a finite element model of a steel tubular crossing frame considering the semi-rigid characteristics of joints was established, and the influence of frame parameters on structural stability and the effective length factor (μ) of the vertical members was analyzed. On this basis, the main factors affecting the effective length factor μ were identified using orthogonal testing and multiple linear regression, and a predictive formula was obtained through curve fitting. The results show that the step distance and number of steps of the horizontal members are the primary factors influencing the bearing capacity and μ value of the crossing frame, followed by the spacing of vertical members, the number of spans, and the number of rows. The height of the bottom sweeping member has a weak influence within the range of 0.1–0.6 m but becomes significantly more influential when it exceeds 0.7 m. The installation of peripheral cross bracing increases the bearing capacity of the crossing frame by at least 20%. The accuracy of the proposed formula was verified by comparing the stresses of the vertical members calculated using the formula, the specifications JGJ130-2019 and BS5975-2019, and the finite element analysis results. The findings provide a useful reference for the stability assessment and erection scheme design of steel tubular crossing frames in transmission engineering.