Piezoelectric wafer active sensors may be applied on aging aircraft structures to monitor the onset and progress of structural damage such as fatigue cracks and corrosion. The state of the art in piezoelectric-wafer active sensors structural health monitoring and damage detection is reviewed. Methods based on (a) elastic wave propagation and (b) the Electro–Mechanical (E/M) impedance technique ...

The aim of the experimental study described in this paper was Lamb wave method evaluation for damage/ defects detection of epoxi/glass composites. Can be used piezoelectric transducers actuator/sensor glued on the surface of investigated composite, using transmission mode. The chosen control parameter was the sensor signal attenuation because of defects that exists in examinated samples. The pr...

When an extreme earthquake occurs, it is essential to detect the severe structural damage that affect the structural safety immediately. This paper proposes a method for quick earthquake damage detection/evaluation of reinforced concrete bridge columns. An intelligent sensor unit is developed that captures changes in the natural period of a bridge column by FFT of response acceleration recorded...

A Particle Swarm Optimization (PSO) algorithm is examined to solve the inverse problem in structural health monitoring. The damage detection problem is formulated as a PSO problem to find a damaged stiffness matrix that satisfies the structure’s eigenequation and satisfying the necessary symmetry, sparsity, positive definiteness, and damage localization constraints. Finally, the PSO technique i...

Temperature variations have significant effects on propagation of Lamb wave and therefore can severely limit the damage detection for Lamb wave. In order to mitigate the temperature effect, a temperature compensation method based on baseline signal reconstruction is developed for Lamb wave-based damage detection. The method is a reconstruction of a baseline signal at the temperature of current ...

the paper presents a mathematical base modeling combined to modified-winding -function-approach (mwfa) for eccentricity fault detection of a round-rotor synchronous machine. for this aim, a 6-pole machine is considered, and the machine inductances are computed by mwfa in healthy and also under eccentricity fault. a numerical discrete-time method has been proposed to machine modeling in voltage-...

based on symbolic manipulation program maple and using riccati equation mapping method several explicit exact solutions including kink, soliton-like, periodic and rational solutions are obtained for (2+1)-dimensional variable coefficient broer--kaup system in quite a straightforward manner. the known solutions of riccati equation are used to construct new solutions for variable coefficient broe...

Pediatric abusive head trauma – once commonly known as the shaken baby syndrome – is a form of child abuse that results in traumatic brain injury. The peak incidence of pediatric abusive head trauma appears to be in children between the ages of 2 to 4 months; the exact incidence of this injury is not known. Pediatric abusive head trauma often results in severe and permanent neurological damage,...

Accurately detection of retinal landmarks, like optic disc, is an important step in the computer aided diagnosis frameworks. This paper presents an efficient method for automatic detection of the optic disc’s center and estimating its boundary. The center and initial diameter of optic disc are estimated by employing an ANN classifier. The ANN classifier employs visual features of vessels and th...

Road damage detection and assessment from high-resolution remote sensing image is critical for natural disaster investigation and disaster relief. In a disaster context, the pairing of pre-disaster and post-disaster road data for change detection and assessment is difficult to achieve due to the mismatch of different data sources, especially for rural areas where the pre-disaster data (i.e., re...