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S.R. Soni², E.D. Swenson³, R.T. Underwood⁴
Structural Longevity, Vol.2, No.2, pp. 63-79, 2009, DOI:10.3970/sl.2009.002.063
Abstract Detecting through-thickness fatigue cracks in a geometrically constrained structure is a challenging structural health monitoring (SHM) problem due to potentially degraded sensor performance. Fatigue cracks are typically found in aircraft structures during visual inspections and non-destructive testing (NDT); however, there exists a real need to detect damage between NDT intervals. Over the last decade, a significant amount of research effort has been focused on developing “hot spot” approaches to monitor areas of structures known to have damage using Lamb waves generated from surface-mounted lead zirconate titanate (PZT) transducers. This research is focused on evaluating an SHM approach for detecting fatigue… More >

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Yasser Sharifi¹, Jeom Kee Paik^1,2
Structural Longevity, Vol.2, No.2, pp. 81-101, 2009, DOI:10.3970/sl.2009.002.081
Abstract This study develops an assessment procedure for the ultimate strength reliability of steel box girder bridges that takes into account the plate member degradation that results from uniform corrosion in different environmental conditions. This paper is a sequel to the authors’ previous paper (Sharifi and Paik 2010), which deals with the effects of pit and general corrosion on the load-carrying capacity and reliability of these bridges. In contrast to that paper, the effects of different environmental conditions on such capacity and reliability are considered herein. Probabilistic corrosion rate parameters based on the available data are provided, and an analytical formula… More >

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Ming-Te Liang^1,2, Jiang-Jhy Chang³, Han-Tung Chang³, Chi-Jang Yeh⁴
Structural Longevity, Vol.2, No.2, pp. 103-128, 2009, DOI:10.3970/sl.2009.002.103
Abstract Engineering experience has clearly shown that existing reinforced concrete (RC) bridges are reliable to damage from environmental attack such as freeze-thaw, alkali-silica reaction, and corrosion. To establish feasible and rational method, reliable prediction of the service life of deteriorating RC bridge is needed. To obtain an exact insight into this problem, time-dependent reliability methods have to be used. In this paper, the reliability of RC girder bridges under corrosion condition is studied using a time-dependent reliability analysis in which both load and resistance are time-dependent. The corrosion process has three stages, the initiation (diffusion or carbonation) time (t_i = t_c),… More >

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JF Liu¹, C Chen², YB Shao³, WF Yuan⁴
Structural Longevity, Vol.2, No.2, pp. 129-137, 2009, DOI:10.3970/sl.2009.002.129
Abstract Yield line theory is commonly used for predicting the load carrying capacity of a tubular joint. Theoretical method and numerical investigation have both been carried out to determine the profile of yield lines on the chord surface for a circular tubular T-joint under axial compression. Two yield lines in a form of closed space curve are assumed to initiate when the axial compressive load reaches a critical value. The first yield line is located along the weld toe, and the second yield line is determined by minimum energy principle. Through finite element simulation and verification, the theoretical method is evaluated… More >

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