Safety evaluation method for ocean platform based on integration of vibration identification frequencies and vibration mode

Abstract

The invention discloses a safety evaluation method for an ocean platform based on integration of vibration identification frequencies and a vibration mode. The method comprises: step one, establishing a finite element model with an undamaged structure to serve as a reference finite element model; performing vibration tests to the undamaged structure, and identifying modal frequencies omega di (i=1,..., m) of front m stages and a vibration mode of the undamaged structure to serve as actual measured modal parameters; and evaluating a whole safety state of a service damaged platform structure. According to the method, safety evaluation of a platform structure can be performed directly on the basis of diagnosis vibration test data identification structure parameter definition and safety evaluation parameters, the problem that structural damage diagnosis and safety evaluation of actual engineering structures are difficult in a structural damage diagnosis method based on vibration detection combination is solved; defects that environmental excitation, noise effects and complete measurement effects are large of conventional methods in actual engineering application are overcome; and the method has the advantages that the computational efficiency is high, the applicability is high, the physical significance is explicit, and the like.

Description

technical field [0001] The invention relates to a method for evaluating the safety of an offshore platform structure, in particular to a method for evaluating the safety of an offshore platform based on vibration identification frequency and mode shape synthesis. It belongs to the field of offshore oil engineering. Background technique [0002] The offshore platform structure is a major infrastructure for the development of offshore oil resources, and at the same time, it is also a base for offshore production operations and living. The offshore platform structure has served in the harsh marine environment for a long time, and is subjected to fatigue loads such as wind, waves and currents for a long time, and the resistance attenuation is very obvious. Once an accident occurs, it will not only cause major economic losses and casualties, but also may cause serious environmental pollution and social and political impact. Therefore, it is very necessary to monitor, detect and...

AI Technical Summary

Problems solved by technology

[0007] The main purpose of the present invention is to overcome the above-mentioned shortcomings existing in the prior art, and provide a method for safety assessment of offshore platforms based on vibration identification frequency and mode shape synthesis, which can directly identify structural parameter definitions and safety assessment based on diagnostic vibration detection data The safety assessment of the platform structure based on parameters solves the problems of structural damage diagnosis and safety assessment of actual engineering structures that are difficult to carry out in the method based on vibration detection combined with structural damage diagnosis; overcomes the problem of the conventional safety assessment method based on vibration detection damage diagnosis in practical engineering applications Insufficiently affected by environmental incentives, noise, and complete measurement; at the same time, it has broad application prospects and practical value for the current situation that a large number of offshore platforms in my country need to be inspected and maintained.

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