Accurate predictive analyses such as those associated with structural reliability and life-cycle costing are needed for the development of Bridge Management Systems. The present paper presents models for reliability and life-cycle cost analyses of reinforced concrete bridges damaged by corrosion. A stochastic deterioration process for corrosion initiation and propagation and then crack initiation and propagation are used to examine the effect of cracking, spalling, and loss of reinforcement area on structural strength and reliability. This will enable expected costs of failure for serviceability and ultimate strength limit states to be calculated and compared for different repair strategies and inspection intervals. It was found that, for a typical reinforced concrete slab bridge, the reduction of structural capacity at the time of severe cracking or spalling is relatively modest and causes probabilities of collapse conditional on spalling to increase by about an order of magnitude. Hence, expected costs of failure for serviceability were significantly higher than the expected costs of failure for ultimate strength limit states.
Dielectric elastomer (DE) generators may be used in harvesting energy from ambient vibrations. Based on existing research on the mechanical properties of a circular DE membrane, a DE-based dynamic vibro-impact system is proposed in this paper to convert vibrational energy into electrical one. The dimensional, electrical and dynamic parameters of the DE membrane are analysed and then used to numerically estimate the output voltage of the proposed system. The system output performances under harmonic excitation are further discussed. At last, the comparison study has been conducted with an electromagnetic energy harvesting system, served as a 'shaking' flashlight.
Reinforced concrete (RC) bridges deteriorate with time. This results in reduction of their resistance, and, consequently, of their reliability. Corrosion of embedded reinforcing steel is one of the main causes of deterioration. The paper presents a method for reliability assessment of RC slab bridges with corroded reinforcement. The method includes a traffic load model, a corrosion model, and a nonlinear finite element structural model. Two types of corrosion—general corrosion, including spalling and debond between concrete and the corroded reinforcement, and localized corrosion—are considered. Reliability is estimated in terms of the reliability index using the first-order reliability method. Uncertainties associated with material properties, geometry, loads, and corrosion parameters are taken into account. A sensitivity analysis of a simple span bridge is carried out to examine the influence of these uncertainties on the bridge reliability. Reliability assessment of a deteriorated three-span continuous bridge illustrates the application of the method.
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