Damage Detection in Post-Tensioned Slab Using 2D Wavelet Transforms

Abstract

Earthquake force, loading more than structural capacity, cracking, material fatigue, and other unpredicted events are undeniable in the structure life cycle in order that environmental conditions of the structure would be changed and treats health. Damage of structures such as crack, corrosion of the post-tension cables from inappropriate grouting of the post-tension structures, etc., can lead to the collapse of the structure. Accordingly, damage detection precedes the damage is essential. In this article, damage detection in the post-tensioned slab through 2D wavelet transform investigated. Hence, the structure has been modeled with finite element method. Damaged cables have been modeled by a reduction of the post-tension force. The vertical displacement has been derived through static analysis of the intact and damaged structure. Damage location will be detected with wavelet transform on the difference of the vertical displacements. To demonstrate the ability of 2D wavelet transform single and multiple scenarios of the post-tension cables, are tested. The influence of noise in the vertical displacement data for these scenarios is also considered. Using 2D wavelet transform and damage index W, an empirical equation has been proposed to calculate damage severity of the post-tensioned slab cables.

Keywords

• damage detection
• signal processing
• 2d wavelet transform
• post-tensioned slab