A damage combination identification method for cable-arch structures based on modal parameters

Abstract

The invention discloses a cable arch structure damage combination identification method based on modal parameters. The method comprises the steps of firstly, collecting accelerating signals set on a cable arch structure, then obtaining inherent frequencies before and after the damage and modal flexibility matrixes of an arch structure part before and after the damage of the structure separately, then solving first-five-order regularized frequency change rate indexes for the inherent frequencies before and after the damage of a cable support part to draw a frequency-and-position curve, buildinga frequency fingerprint base, then calculating frequency fingerprint parameters in the actual damage situation, locating corresponding frequency fingerprint curves, finding out damage positions corresponding to all-order frequency fingerprints and conducting sifting, then solving first-three-order modal flexibility difference curvature indexes for the modal flexibility matrixes before and after damage of a cable arch part respectively, finally, according to the modal flexibility difference curvature indexes, drawing a first-three-order modal flexibility difference curvature-and-position curve, and finding out the curve mutation position, namely the damage position, wherein the larger the mutation is, the larger the damage degree is. By means of the cable arch structure damage combinationidentification method based on the modal parameters, the cable arch structure can be effectively subjected to damage locating under single-damage and multi-damage working conditions, and the damage degree can also be precisely identified.

Description

Technical field: [0001] The invention relates to the technical field of damage identification and diagnosis of long-span steel structures, in particular to a damage combination identification method for cable-arch structures based on modal parameters. Background technique: [0002] Long-span steel structure is one of the important symbols to measure the level of a country's construction technology. Due to its beautiful shape, reasonable economy and strong spanning ability, long-span steel structures have developed rapidly in my country. Among them, the string beam structure is a space hybrid structure formed by combining the upper rigid arch truss and the lower flexible cable through the struts. It is used in Harbin Sports Convention and Exhibition Center, Guangzhou International Convention and Exhibition Center, Shenzhen Convention and Exhibition Center, Shanghai World Expo Theme Pavilion, National It has been successfully applied in many major projects such as gymnasiums,...

AI Technical Summary

Problems solved by technology

[0013] The large-span steel structure has a large scale and various members, especially in the prestressed string beam structure, there are different types of members such as cables, struts and trusses, and the force mechanism is more complicated. The damage identification is different from that of conventional bridge structures or multi-story structures Significant differences exist in the building structure

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