Brace Damage Detection of a Transmission Tower Utilizing Vibration Data
作者单位：Department of Civil and Architectural EngineeringCity University of Hong Kong
会议名称：《The 16th Annual Conference of Hong Kong Society of Theoretical and Applied Mechanics 2012、The 1st Mainland-Hong Kong Youth Forum on Mechanics 2012、The 8th Shanghai-Hong Kong Forum on Mechanics and Its Application 2012》
会议日期：2012年
学科分类：080802[工学-电力系统及其自动化] 0808[工学-电气工程] 08[工学]
基 金：supported by a grant from City University of Hong Kong(7002589)
关 键 词：Brace Damage Detection of a Transmission Tower Utilizing Vibration Data
摘 要：Transmission towers play a very significant role in the distribution of electrical *** structural health monitoring of transmission towers is an important research *** is impractical and impossible to develop a general method that can detect all kinds of damage for all types of structures. For transmission towers,brace buckling due to strong wind load during typhoon is not uncommon (Yin et al.2009;Lam and Yin 2011).To address this problem,this paper reports a feasibility study on the use of vibration data of transmission tower in the detection of damaged braces by following a model-based *** of the important contributions of this paper is the vibration test of a scaled transmission tower(see Figure 1) under laboratory conditions. Modal identification was carried out by MODE-ID(Beck 1979) and the natural frequencies and mode shapes of the transmission tower were obtained from impact hammer tests.A self-developed MATLAB program is then employed to establish the model-predicted modal parameters of the *** updating was conducted by minimizing the discrepancy between model-predicted and measured modal parameters to identify an optimal model to represent the healthy transmission *** the experimental verification,different damage patterns were considered by removing different brace *** each damage pattern,the modal parameters of the damaged tower were measured by impact hammer *** the model updating of the damaged structure,a dimensionless scaling factor is applied on the Young s modulus of each possibly damaged brace *** scaling factor takes a value of 1 to 0.A value of 1 means undamaged and the stiffness of the brace is 100%retrained;A value of 0 means completely damage and 100%loss of stiffness. Those factors will be included in the model updating of the damaged *** other words,the updated scaling factors can tell the locations and extents of damage.