Guided ultrasonic waves are increasingly used in all those structural health monitoring applications that benefit from built-in transduction, moderately large inspection ranges, and high sensitivity to small flaws. This article describes a system based on the generation detection of guided an array sparse transducers. In round-robin manner, generated measured possible different pairs excitation sensing The signals then processed using continuous wavelet transform empirical mode decomposition...

The principal purpose of this article is to present a novel methodology based on wavelet packet transform techniques and stochastic neural networks generate more artificial earthquake accelerograms from available data, which are compatible with specified response spectra or the design spectra. proposed method uses decomposing capabilities accelerograms, learning abilities network expand knowledge inverse mapping spectrum coefficients accelerogram. This results in ensemble and, they used...

Incomplete sensed data in structures have made exact structural damage detection a serious challenge. In this paper, an effective method is presented for and estimation based on incomplete modal of damaged structure via pattern search algorithm. An objective function the condensed mass stiffness matrices formulated. The proposed determines to elements using optimization by performance has been verified through two numerical examples, namely, two-span continuous beam three-story plane frame...

In this paper, a novel and effective damage diagnosis algorithm is proposed to localize quantify structural using incomplete modal data, considering the existence of some limitations in number attached sensors on structures. The detection problem formulated as an optimization by computing static displacements reduced model structure subjected unique load. responses are computed through flexibility matrix damaged obtained based data structure. algorithm, iterated improved reduction system...

This paper is aimed at presenting two methods on the basis of pattern search and genetic algorithms to detect estimate damage in plates using modal data a damaged plate. The proposed determine damages plate structures optimization an objective function by algorithms. These have been applied numerical examples, namely four-fixed supported cantilever with without noise containing one or several damages. obtained results clearly reveal that can be viewed as powerful reliable method for...

An effective method for detection linear flaws in plate structures via two-dimensional discrete wavelet transform is proposed this study. The was applied to a four-fixed supported rectangular containing damage with arbitrary length, depth and location. Numerical results identifying the location are compared actual demonstrate effectiveness of method. Also, wavelet-based presented de-noising mode shape plate. Finally, performance identification verified using experimental data. Comparison...

Slender columns subjected to compressive stress are common in many civil structures. The rapid situ measurement of this may prevent structural buckling. In study, the authors applied an artificial neural network (ANN) process numerical data that describe coupling mechanism between highly nonlinear solitary waves (HNSWs) propagating along a granular system and beam contact with medium. aim is evaluate ability HNSWs measure thermally loaded structures estimate neutral temperature, i.e.,...

In this paper, two effective damage detection methods for localizing and quantifying structural in shear frames are presented. Both of them based on the diagonalization stiffness matrix frames. The first method is devoted to estimating by modification modal residual force while second computation static displacements under a unique using only few modes. most important feature presented their simplicity damage. proposed algorithms have been numerically applied show that they can successfully...

This paper presents a new algorithm to determine the occurrence, location, and severity of damage in structures subjected earthquakes. The is based on analysis time series associated with displacement or acceleration, provided by limited number sensors. formulated terms an optimization problem. An objective function defined moment generating for segment histories evolutionary strategy, competitive algorithm, employed detect damage. efficiency proposed method numerically validated studying...

This paper presents a method for detection and estimation of structural damage on the basis modal parameters damaged structure using imperialist competitive algorithm. The algorithm was developed over last few years in an attempt to overcome inherent limitations traditional optimize method. In this research, has been employed due its favorable performance damages. proposed verified through benchmark problem provided by IASC-ASCE Task Group Structural Health Monitoring number numerical...

We present an experimental study where guided ultrasonic waves were used for the noncontact nondestructive evaluation of aluminum plate immersed in water. Broadband leaky Lamb generated using a pulsed laser and detected with array immersion transducers arranged semicircle. The signals processed to extract some features from time, frequency, joint time-frequency domains. These then fed unsupervised learning algorithm based on outlier analysis detect presence damage, supervised artificial...

This paper presents a method for detection and estimation of structural damage on the basis modal parameters damaged structure using imperialist competitive algorithm. The algorithm was developed over last few years in an attempt to overcome inherent limitations traditional optimize method. In this research, has been employed due its favorable performance damages. proposed verified through benchmark problem provided by IASC-ASCE Task Group Structural Health Monitoring number numerical...

Highly nonlinear solitary waves (HNSWs) are compact nondispersive that propagate in medium such as straight chains of spherical particles. In the last two decades, these have found many applications physics and engineering including lensing nondestructive testing. study presented this paper, we exploit propagation HNSWs along a metamaterial formed by granular to harvest energy from an oscillating structure. Specifically, oscillator taps creates train each chain. At interface between solid...

The in-situ measurement of axial stress in beams may prevent structural anomalies, such as unexpected buckling. We describe the coupling mechanism between highly nonlinear solitary waves (HNSWs) propagating along a granular system and beam contact with medium to assess ability HNSWs measure stress. One two straight chains particles were considered effect particles' diameter material was evaluated find those designs that maximize sensitivity variation In future, our findings be used develop...

This paper suggests the use of wavelet multiresolution analysis (WMRA) and neural network for generation artificial earthquake accelerograms from target spectrum. procedure uses learning capabilities radial basis function (RBF) to expand knowledge inverse mapping response spectrum accelerogram. In first step, WMRA is used decompose several levels that each level covers a special range frequencies, then every RBF trained learn relate coefficients. Finally generated accelerogram using discrete...

Considering the vast usage of time-history dynamic analyses to calculate structural responses and lack sufficient suitable earthquake records, generation artificial accelerograms is very necessary. The main target this paper present a novel method based on nonstationary Kanai-Tajimi model wavelet transform generate more which are compatible with spectrum. In regard, generalized include evaluation amplitude dominant frequency ground motion properties used acceleration time history....