Damage Identification Of Rigid Tied-bar Arch Bridge Suspender Based On Transient Dynamics Analysis

Rigid tie-bar arch bridge is an important form of the cable-system bridge, which span is generally between 50 to 150 meters, and quantity is multitudinous. The rigid tie-bar arch bridge suspension bar form quite is diverse, the partial bridges used the coat steel pipe steel wire which the cement mortar fills to tie. It's very difficultly carries on the examination through the conventional method, but says as the suspension bar, it is pulled the probability to high, its damage recognition methods research is extremely important. The method of damage identification of the suspender is very important.This paper studies the theory, which is damage identification of rigid tie-bar arch bridge suspender base on transient dynamics analysis. Use the frequency band relative energy accumulation rate of change target to analysis the acceleration signal. Then use of statistical methods to determine the damage position of rigid tie-bar arch bridge suspender. This article main research results of the paper are as follows:①Start from the wavelet packet energy spectrum. Define that the relative energy Frequency band is the acceleration signal by wavelet packet decomposition of each band signal on the signal energy and the ratio of the total energy. Frequency band relative energy rate of change is the ratio of the absolute value for the before and after damage of the relative energy frequency band difference with the relative energy frequency band of before damage. Ultimately define the frequency band relative energy accumulation rate of wavelet packet is the sum of all frequency band relative energy rate of change. And achieve the confidence level limit of all measuring points'the frequency band relative energy accumulation rate as the distinction basis. Once when some measuring point target surpasses the confidence limit, we can judge that this point correspondence position existence damage.②Proposed the frequency band relative energy accumulation rate of wavelet packet as the distinction target, take the impulsive load as moves the load excitation the transient state dynamic method. Confirmed this method through the value simulation to have the feasibility in the recognition which the rigid tie-bar arch bridge suspender damaged.③Analysis the rigid tie-bar arch bridge power computation model and actual bridge structure different influence, namely computation model rough influence. after the analysis we can require, when uses which this paper to propose the method carries on the rigid tie-bar arch bridge suspender damage recognition, the calculation model of roughness effects too small to affect the results of damage identification. The analysis of roughness to theoretical models for the finite element analysis results before the actual bridge replacement damage test signals provide a feasible basis.④Through simulated two aspects from the theory and the value to prove that has the load have the same form but the load peak-to-peak value differently to examine the result not to affect, and proposed attacked the load to take the drive load the experimental load method, the characteristic which simple also easy to control using the impact load method, solved the actual bridge to move many times well measured the experiment moved the load to be unable the consistent question.⑤Has carried on around the plexiglass model damage transient state dynamics loading test in the laboratory, through to power acceleration signal gathering and the analysis, has confirmed the rigid tie bar arched bridge suspension bar damage recognition examination method feasibility which this paper studies.