Damage Detection Of Historic Timber Structure Under Random Excitation Based On Cross Correlation Function Amplitude Vectors

Most of ancient architectural structures are wooden structures in China. It is thehistorical precipitation of Chinese excellent cultural, and becomes an important part ofChinese civilization. Ancient buildings suffered varying degrees of damage anddestruction in hundreds of years or even thousands of years due to surroundingenvironment, natural and human factors. Random vibration caused by environmentalincentive like modern traffic would lead sustained damage to the ancient buildings,which inevitably cause damage accumulation and resistance decay and then lead tostructure destruction. Therefore, it has great significant to do research on damagedetection of ancient architectures based on stochastic excitation to protect ancientarchitecture buildings.Through the analysis of ancient wooden structure in this paper, relevantparameters of ancient wooden beam are selected, which is the typical ancientarchitectural structure, finite element model of wooden beam is established usinggeneral finite element software ANSYS. Cross-correlation Function Amplitude Vectormethod is employed to do the damage detection and position analysis under randomexcitation of wooden structures, along with reducing the damage of element stiffnessanalogue. Main research contents are as following:Firstly, the characteristic of stationary shape is proved through Calculating theCross-correlation Function Amplitude Vector of two intact structures which under two randomexcitations having stability spectrum, and take the damage factor of two intact structures as a standard which provide a reference value for damage detection.Secondly, distinguishing the damage of structure according to the change ofdamage factor between damaged and intact structures.Finally, damage locating of structure is realized according to the relative changeof each corresponding element, in which the adjacent maximum corresponding to twonodes of damage elements. According to the relation between surface strains anddeflection of beam, the feasibility of this method was verified by taking the relativechanges of the displacement response’s Cross-correlation Function Amplitude Vector aftersecond order difference and strain response’s are compared.