Simply-supported piece damage identification method based on strain statistical moment

Abstract

The invention discloses a simply-supported piece damage identification method based on a strain statistical moment. The simply-supported piece damage identification method comprises the following steps: (1) uniformly distributing a plurality of strain gages on a simply-supported piece as measuring points and respectively obtaining strain statistical moment vectors of all the measuring points of the simply-supported piece under undamaged and damaged states, and determining a damaged part on the simply-supported piece by using a difference value between the strain statistical moment vectors; (2) establishing a finite element model and dividing a finite element unit; simulating a power process the same as the step (1) to obtain an analysis vector formed by the strain statistical moments of all nodes under a simulated state; and (3) carrying out model revising by using a least square method according to a damaged part positioned by the step (1) to obtain a damage degree of the potential damage finite element model. The advantages that the strain statistical moment is sensitive to partial damages and also has a good anti-noise capability are utilized so that the change of the simply-supported piece before and after damages can be directly used for positioning the structure damages; the good anti-noise capability of the strain statistical moment can be used for effectively improving the damage degree identification precision.

Description

Technical field [0001] The invention belongs to the technical field of civil engineering structural health monitoring and damage identification, and more specifically, relates to a simple-supported component damage identification method based on strain statistical moments. Background technique [0002] Civil engineering structures, including bridges, civil buildings, and industrial plants, are often directly related to the safety of public property. From the beginning of construction to service, the stiffness of the structure will continue to be damaged under the action of wind load, seismic load, man-made impact load, fatigue load and chemical corrosion, resulting in so-called structural damage. When these damages accumulate to a certain degree, they will The mechanical performance of the overall structure has a negative impact, and the severe cases may even cause the structure to eventually fail, causing serious casualties and property damage. In order to ensure the safe opera...

AI Technical Summary

Problems solved by technology

However, the biggest defect of the damage identification method based on modal index is that it is insensitive to local damage and very sensitive to measurement noise.

Images