Truss structure damage evaluation method based on pulsation test

Abstract

The invention discloses a truss structure damage evaluation method based on a pulsation test, and relates to the field of structure health monitoring. The method comprises the steps: firstly, numbering all rod pieces of a truss structure and degrees of freedom of all end nodes of the rod pieces, and establishing a finite element model of the truss structure to obtain a rigidity matrix and a mass matrix; secondly, mounting wireless acceleration sensors on all nodes of the truss structure, and recording characteristic values of all orders of structural pulsation and corresponding vibration modes; carrying out normalization operation on each order of vibration mode; calculating a virtual displacement matrix, a damage index vector and a damage degree factor of the truss structure; and finally,evaluating the position of the damaged rod pieces according to the damage index vector, and evaluating the damage degree according to the damage degree factor. When the method is used for evaluatingthe damage of the truss structure, no special manual excitation external load needs to be applied, and the time and cost required by damage evaluation can be saved.

Description

technical field [0001] The invention relates to the field of structural health monitoring, in particular to a pulsation test-based damage assessment method for truss structures. Background technique [0002] Truss structures are widely used in civil, mechanical, aviation and marine engineering fields, such as steel truss roofs, steel truss bridges, tower cranes, crane arms, offshore platforms, etc. Due to factors such as environmental corrosion, material fatigue, and loose connectors, structural damage will inevitably occur. Only by timely and accurately identifying the damage in the structure can a corresponding reinforcement and maintenance plan be adopted to avoid major safety accidents. In recent years, several damage assessment methods for truss structures have been proposed. [0003] Patent CN102495134B discloses a damage location method for truss structures based on additional mass, which uses the comparison of the peak position of the frequency response of the bar a...

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Problems solved by technology

[0003] Patent CN102495134B discloses a truss structure damage location method based on additional mass, using the comparison of the frequency response peak position of the bar after adding the mass to judge the position of the bar damage. Although the cost is low and the operation is simple, it often requires special external loads It is unrealistic and uneconomical for large-scale truss structures, so there is an urgent need for a damage assessment method that can use structural pulsation test data without additional artificial excitation loads, which can Save time and money spent on damage assessments

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