STUDY ON THE CONCRETE DAMAGE EVOLVEMENT AND DAMAGE DETECTION IN R.C BEAMS BY WAVELET ANALYSIS

摘要

Based on the analysis of the present concrete damage model, new concretes damage evolution equation and the concrete tension constitutive equation are proposed, which is in simple style. In order to detect damage of simple-supported reinforced concrete(R.C) beams, experiment set-up for R.C beams dynamic test was designed, in this test, beam was subjected to an increasing static load in the middle to introduce cracks, and the last load step corresponded to failure. After each load step and unloading, beam crack width was investigated and an experimental dynamic monitoring was performed. Multiple degree freedom dynamic equation of the test beams was wavelet transformed, and structural dynamic response expression on multi-scale was acquired. It's shown that multi-scale decomposition of signal comprises more structural damage information. By means of DASP signal processing system, binary wavelet transformation was applied to dynamic signal of reinforced concrete beams on different damage state. Through analyzing wave-figure of all frequency scales, the damage of reinforced concrete beams was determined.