V. Mallardo^1,2, M.H. Aliabadi³

Structural Durability & Health Monitoring, Vol.9, No.4, pp. 287-323, 2013, DOI:10.32604/sdhm.2013.009.287

Abstract The optimum location of the sensors is a critical issue of any successful Structural Health Monitoring System. Sensor optimization problems encompass mainly three areas of interest: system identification, damage identification and impact identification. The current paper is intended as a review of the state of the art at the year 2012 and going back to 1990. The above topics have been dealt with in separate contexts so far but they contain interesting common elements to be exploited. More >

Mehdi Mohammadpour Lima^1,2, Dane Miller¹, Jeung-Hwan Doh¹

Structural Durability & Health Monitoring, Vol.9, No.4, pp. 269-285, 2013, DOI:10.32604/sdhm.2013.009.269

Abstract Iran is located in a seismic prone region with several earthquakes occurring annually causing extensive damage to structures and infrastructure. Guilan province is located in the northern part of the country, exhibiting a large population, moderate climate and extensive river system. This region experiences high humidity, several active faults and high seismic hazard potential. This highlights the importance of an active and extensive maintenance and rehabilitation program for the bridges in this region. Structural Health Monitoring (SHM) is an engineering tool used to control changing conditions of infrastructure providing useful information for management, decision making and in certain circumstances code… More >

Dongyue Gao¹, Yishou Wang¹, Zhanjun Wu¹, Rahim Gorgin¹

Structural Durability & Health Monitoring, Vol.9, No.3, pp. 233-252, 2013, DOI:10.32604/sdhm.2013.009.233

Abstract In this study, a Lamb wave-based damage extension diagnosis method to monitor the damage on typical structures of composite aircraft is proposed. First, an overview of the damage extension diagnosis method is given. In the method, probability-based damage diagnostic imaging was combined with empirical threshold value to distinguish damage location and estimate damage size in damage extension process. To validate the effectiveness of method, extension diagnosis of simulate delamination damage in typical structure on aircraft were processed. To illustrate the capability of the damage extension diagnostic method, a delamination growth monitoring experiment was performed in a typical reinforce component (Tjoint… More >

G. Savaidis¹, M. Malikoutsakis¹, A. Jagenbrein², A. Savaidis³, M. Soare⁴, M.V. Predoi⁴, A. Soare⁴, I.C. Diba⁴

Structural Durability & Health Monitoring, Vol.9, No.2, pp. 129-154, 2013, DOI:10.32604/sdhm.2013.009.129

Abstract Development of corrosion or/and fatigue crack propagation are the most common causes of structural degradation in road and railway tank vessels. An acoustic emission based monitoring procedure in conjunction with follow-up nondestructive testing is here proposed as a promising alternative to the conventional inspection processes enabling continuous health monitoring of the tank structures. Thereby, finite element analysis taking the respective ADR and RID tank design loads into account is proposed as a capable tool to be applied in early stages of development to reveal the hot spot areas, where acoustic emission sensors have to be positioned. The developed health monitoring… More >

A. Rama Mohan Rao¹, S. Krishna Kumar¹, K. Lakshmi¹

Structural Durability & Health Monitoring, Vol.8, No.3, pp. 271-294, 2012, DOI:10.32604/sdhm.2012.008.271

Abstract Current advancements in structural health monitoring, sensor and sensor network technologies have encouraged using large number of sensor networks in monitoring spatially large civil structures like bridges. Large amount of spatial information obtained from these sensor networks will enhance the reliability in truly assessing the state of the health of the structure. However, if sensors go faulty during operation, the feature extraction techniques embedded into SHM scheme may lead to an erroneous conclusion and often end up with false alarms. Hence it is highly desirable to robustly detect the faulty sensors, isolate and correct the data, if the data at… More >

I. Benedetti¹, A. Milazzo¹, M.H. Aliabadi²

Structural Durability & Health Monitoring, Vol.5, No.3, pp. 251-274, 2009, DOI:10.3970/sdhm.2009.005.251

Abstract In this work a three-dimensional BEM model is used for the analysis of structures with cracks and surface bonded piezoelectric PZT patches used as strain sensors. The cracked structure is modelled by the dual boundary element method, which allows for accurate and reliable crack analysis, while the piezoelectric patch is analyzed by a finite element state-space approach, that embodies both the full electro-mechanical coupling and the suitable sensor's boundary conditions. The model is used to investigate the strain-transfer mechanism from an host elastic structure to the piezoelectric layer, taking into account the effect of the adhesive layer, as well as… More >

S.Mohanty¹, A. Chattopadhyay², J. Wei³, P. Peralta⁴

Structural Durability & Health Monitoring, Vol.5, No.3, pp. 227-250, 2009, DOI:10.3970/sdhm.2009.005.227

Abstract This paper proposes unsupervised system identification based methods to estimate time-series fatigue damage states in real-time. Ultrasound broadband input is used for active damage interrogation. Novel damage index estimation techniques based on dual sensor signals are proposed. The dual sensor configuration is used to remove electrical noise, as well as to improve spatial resolution in damage state estimation. The scalar damage index at any particular damage condition is evaluated using nonparametric system identification techniques, which includes an empirical transfer function estimation approach and a correlation analysis approach. In addition, the effectiveness of two sensor configurations (configuration 1: sensors placed near… More >

S.Mohanty¹, A. Chattopadhyay², J. Wei³, P. Peralta⁴

Structural Durability & Health Monitoring, Vol.5, No.1, pp. 33-56, 2009, DOI:10.3970/sdhm.2009.005.033

Abstract The current state of the art in the area of real time structural health monitoring techniques offers adaptive damage state prediction and residual useful life assessment. The present paper discusses the use of an integrated prognosis model, which combines an on-line state estimation model with an off-line predictive model to adaptively estimate the residual useful life of an Al-6061 cruciform specimen under biaxial loading. The overall fatigue process is assumed to be a slow time scale process compared to the time scale at which, the sensor signals were acquired for on-line state estimation. The on-line state estimation model was based… More >

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 >