Power transmission tower structure initial geometric defect simulation method based on linear buckling analysis

Abstract

The invention discloses a power transmission tower structure initial geometric defect simulation method based on linear buckling analysis, and belongs to the technical field of power transmission tower structure design. The characteristic modal assembly method mainly comprises the following steps: establishing an ideal power transmission tower numerical model which does not contain initial geometric defects according to a design drawing, and applying an external load to carry out linear buckling analysis on the ideal power transmission tower numerical model; and extracting buckling modes which appear at the same position and respectively only comprise one half wave, two half waves and three half waves from the buckling modes obtained by the linear buckling analysis, and linearly superposing the extracted buckling modes at respective corresponding positions according to the precedence order to form a power transmission tower model with the initial geometric defect. Geometric defects obtained through the characteristic modal assembly method are evenly distributed along the tower body, buckling modes with the high half-wave number are combined, the obtained geometric defects better conform to reality compared with defects of a single buckling mode form, meanwhile, the construction process of the geometric defects is simple, and high operability is achieved.

Description

technical field [0001] The invention belongs to the technical field of transmission tower structure design, and in particular relates to a method for simulating initial geometric defects of a transmission tower structure. Background technique [0002] The transmission tower structure is an important lifeline engineering structure, mainly used to support wires and lightning protection lines, and its safety will directly affect the safe operation of the power grid and the production and life of society. In the process of tower component transportation, tower assembly construction, wire erection construction and later operation and maintenance, various initial geometric defects will inevitably occur in the structure of the transmission tower, such as node deviation in the process of manufacturing and installation, and initial bending of components. And initial eccentricity, assembly stress caused by various reasons, etc., these defects and their second-order effects will greatl...

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Problems solved by technology

The consistent defect mode method uses the lowest order buckling mode of the structure to simulate geometric defects, but the lowest order buckling mode is not necessarily the most unfavorable defect distribution, and the higher order buckling mode may be more unfavorable. For details, see Zhang Ailin, Zhang Xiaofeng, Ge Jiaqi et al. 2008 Research on the Influence of Initial Defects in the Overall Stability Analysis of Tensioned Reticulated Shell Structure in Olympic Badminton Stadium [J]. Space Structure, 2006(04): 8-12; Studies have shown that this method cannot accurately predict power transmission when it is used in transmission tower structures For the failure modes of the tower structure, see FU X, WANG J, LIH N, et al. Full-scale test and its numerical simulation of a transmission tower under extreme wind loads [J]. Journal of Wind Engineering an

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