G. Giridhara¹, S. Gopalakrishnan²

Structural Durability & Health Monitoring, Vol.5, No.1, pp. 1-32, 2009, DOI:10.3970/sdhm.2009.005.001

Abstract In this paper, a new damage measure in the frequency domain (FDI), which uses the definition of strain energy in the frequency domain, is proposed. The proposed damage index is derived using the definition of frequency domain strain energy. The base line responses and the strain energies are computed using Wavelet Spectral Finite elements, while the strain energies for the damaged structure is computed using four high fidelity experimental responses. The sensitivity of the damage measure in locating cracks of different sizes and orientation is demonstrated on a square plate, the rectangular plate and on a compressor blade. More >

B.K.Raghuprasad¹, N.Lakshmanan², N.Gopalakrishnan², K.Muthumani²

Structural Durability & Health Monitoring, Vol.4, No.3, pp. 117-144, 2008, DOI:10.3970/sdhm.2008.004.117

Abstract The reduction in natural frequencies, however small, of a civil engineering structure, is the first and the easiest method of estimating its impending damage. As a first level screening for health-monitoring, information on the frequency reduction of a few fundamental modes can be used to estimate the positions and the magnitude of damage in a smeared fashion. The paper presents the Eigen value sensitivity equations, derived from first-order perturbation technique, for typical infra-structural systems like a simply supported bridge girder, modelled as a beam, an end-bearing pile, modelled as an axial rod and a simply supported plate as a continuum… More >

C.P. Providakis¹, M.E. Voutetaki

Structural Durability & Health Monitoring, Vol.3, No.4, pp. 211-228, 2007, DOI:10.3970/sdhm.2007.003.211

Abstract Piezoceramic transducers have emerged as new tools for the health monitoring of large-scale structures due to their advantages of active sensing, low cost, quick response, availability in different shapes, and simplicity for implementations. In the present paper, a statistical metamodeling utilization of electro-mechanical (E/M) admittance approach by applying piezoelectric materials to the damage identification is investigated. A response surface metamodel is constructed by empirically fitting a model to a set of design points chosen using a Box-Behnken design of experiment (simulation) technique. This empirical fit allows polynomial models to be produced for relating damage parameter such that stiffness reduction to… More >

S.P.L. Leme¹, M.H. Aliabadi², L.M. Bezerra¹, P.W. Partridge¹

Structural Durability & Health Monitoring, Vol.3, No.3, pp. 121-132, 2007, DOI:10.3970/sdhm.2007.003.121

Abstract The coupled electromechanical behaviour of a thin piezoceramic sensor bonded to a stiffened panel subjected to membrane mechanical loadings is examined. The sensor is characterised by an electrostatic line model bonded to a damaged panel modelled by the dual boundary element method. Numerical results obtained demonstrate that the proposed method is capable of modelling changes in the signal output due to presence of cracks. Also presented is a numerical model for detecting fatigue crack growth in a stiffened panel using piezoceramic sensors. More >

Hyung-Jo Jung, Jong-Jae Lee, Jeong-Su Park

The International Conference on Computational & Experimental Engineering and Sciences, Vol.19, No.4, pp. 125-126, 2011, DOI:10.3970/icces.2011.019.125

Abstract A vision-based displacement measurement method for structural health monitoring of large-scale infrastructures such as high-rise buildings and long-span bridges is presented. The method uses digital image processing techniques including a target recognition algorithm, projection of the captured image, and calculation of the actual displacement using target geometry and the number of pixels moved. To measure the displacement of a flexible structure from a distant location which can be regarded as a fixed reference point, a novel image processing method has been devised by means of successive estimation of relative displacement and rotational angle using a synchronized vision-based system. By measuring… More >

C.M. Lan¹, H. Li¹

The International Conference on Computational & Experimental Engineering and Sciences, Vol.12, No.3, pp. 75-82, 2009, DOI:10.3970/icces.2009.012.075

Abstract Stay cables are some of the most critical structural components of a bridge. However, stay cables readily suffer from corrosion damage and stress corrosion damage. Thus, health monitoring of stay cables is important for ensuring the integrity and safety of a bridge. Glass Fibre Reinforced Polymer Optical Fibre Bragg Grating (GFRP-OFBG) cable, a kind of fibre Bragg grating optical sensing technology-based smart stay cables, is proposed in this study. The fabrication procedure of the smart stay cable was developed and the self-sensing property of the smart stay cable was calibrated. The application of the smart stay cables on the Tianjin… More >

Chang Kook Oh¹, Hoon Sohn¹

The International Conference on Computational & Experimental Engineering and Sciences, Vol.8, No.3, pp. 91-100, 2008, DOI:10.3970/icces.2008.008.091

Abstract Structural Health Monitoring (SHM) is concerned with identifying damage based on measurements obtained from structures being monitored. For the civil structures exposed to time-varying environmental and operational conditions, it is inevitable that environmental and operational variability produces an adverse effect on the dynamic behaviors of the structures. Since the signals are measured under the influence of these varying conditions, normalizing the data to distinguish the effects of damage from those caused by the environmental and operational variations is important in order to achieve successful structural health monitoring goals. In this paper, kernel principal component analysis (kernel PCA) using unsupervised support… More >

C. A. Featherston¹, M. Eaton¹, R. Pullin¹, K. M. Holford¹

The International Conference on Computational & Experimental Engineering and Sciences, Vol.10, No.1, pp. 29-36, 2009, DOI:10.3970/icces.2009.010.029

Abstract This article has no abstract. More >

Guang Chen^1,*, Keqin Ding¹, Qibo Feng², Xinran Yin¹, Fangxiong Tang¹

Structural Durability & Health Monitoring, Vol.13, No.3, pp. 289-301, 2019, DOI:10.32604/sdhm.2019.05144

Abstract The grating ends bonding fiber Bragg grating (FBG) sensor has been widely used in sensor packages such as substrate type and clamp type for health monitoring of large structures. However, owing to the shear deformation of the adhesive layer of FBG, the strain measured by FBG is often different from the strain of actual matrix, which causes strain measurement errors. This investigation aims at improving the measurement accuracy of strain for the grating ends surface-bonded FBG. To fulfill this objective, a strain transfer equation of the grating ends bonding FBG is derived, and a theoretical model of the average strain… More >

Rui Lu¹, Zhanjun Wu¹, Qi Zhou¹, Hao Xu^1,*

Structural Durability & Health Monitoring, Vol.13, No.3, pp. 267-287, 2019, DOI:10.32604/sdhm.2019.06323

Abstract Structural health monitoring (SHM) is a research focus involving a large category of techniques performing in-situ identification of structural damage, stress, external loads, vibration signatures, etc. Among various SHM techniques, those able to monitoring structural deformed shapes are considered as an important category. A novel method of deformed shape reconstruction for thin-walled beam structures was recently proposed by Xu et al. [1], which is capable of decoupling complex beam deformations subject to the combination of different loading cases, including tension/compression, bending and warping torsion, and also able to reconstruct the full-field displacement distributions. However, this method was demonstrated only under… More >