Detection method of steel pipe concrete cavity defect extracted on basis of HHT characteristics

Abstract

The invention discloses a detection method of a steel pipe concrete cavity defect extracted on the basis of HHT characteristics. The method comprises the following steps: (1) applying mechanical impact on a detection point on the surface of steel pipe concrete to excite stress waves, using a sensor to receive the stress wave detection signals; (2) adopting an HHT algorithm to extract cavity characteristic signals from the stress wave detection signals to obtain a characteristic Hilbert marginal spectrum; (3) changing the detection point, repeating step (1) and (2); subjecting the characteristic Hilbert marginal spectrums corresponding to different detection points to an image wave train display; and judging the size of cavity of steel pipe concrete according to the characteristic Hilbert marginal spectrum. By accumulatively displaying the images of characteristic Hilbert marginal spectrums of multiple detection points, the situation of cavity defects in steel pipe concrete can be directly display and calculated, and the method has the advantages of strong reliability, and accurate detection result.

Description

technical field [0001] The invention relates to a detection method for hollow defects of steel pipe concrete, in particular to a detection method for hollow defects of steel pipe concrete based on HHT feature extraction. Background technique [0002] Concrete filled steel pipe is a composite building material widely used in high-rise buildings, industrial plants and bridge engineering. Since the core concrete is bound by the outer steel pipe, the steel pipe and concrete interact with each other when bearing the force, making its compressive strength, plasticity and toughness much higher than that of traditional building materials. The key to the composite structure of steel pipe concrete is to make the concrete and the steel pipe wall tightly combined, so as to realize the designed composite performance. During the construction of concrete filled steel pipe, it is easy to cause voids, looseness, construction joints and uneven structure inside the concrete material, resultin...

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Problems solved by technology

It is difficult to extract the main frequency value of the eigenmode by using the traditional direct fast Fourier transform, and the single-point main frequency value corresponding to the void situation of the concrete

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