Electronic speckle pattern interferometry has been used to study the deflection shapes of a piano soundboard. A design for an interferometer that can image such an unstable object is introduced, and interferograms of a piano soundboard obtained using this interferometer are presented. Deflection shapes are analyzed and compared to a finite-element model, and it is shown that the force the strin...

This paper presents a two-step method for damage localization in beams by combining natural frequencies and mode shapes. The general locations of the are first identified from an indicator developed using relative frequency change (RNFC) curves values RNFCs. A curvature-mode-shape-based is then utilized to determine specific location second step. proposed verified detecting simulated simply-sup...

Initially, the first aim of the present study is to model 3-axle rigid truck by developing a code in Matlab. Secondly, each equation should be drived by acquisition of Lagrange approach. After deriving equations successfully, validation is performed by some result which was mentioned in Bohao Li's master thesis. Although the present approach is totally different from the approach that Boahao Li...

Initially, the first aim of the present study is to model 3-axle rigid truck by developing a code in Matlab. Secondly, each equation should be drived by acquisition of Lagrange approach. After deriving equations successfully, validation is performed by some result which was mentioned in Bohao Li's master thesis. Although the present approach is totally different from the approach that Boahao Li...

A tool is needed to track several mode shape estimates from iterative or repeated (variability) testing. Modal Assurance Criterion (MAC) is a well known modal vector comparison tool, however it can compare only two modal vectors at a time. A method to compare multiple samples of modal vector is presented The approach begins with mode shape correlation and correspondence. Pseudo orthogonality is...

An extensive program of full-scale ambient vibration testing has been conducted to measure the dynamic response of a 240 meter cable-stayed bridge–Gi-Lu Bridge in Nan-Tou County, Taiwan. A MEMS-based wireless sensor system and a traditional microcomputer-based system were used to collect and analyze ambient vibration data. A total of four bridge modal frequencies and associated mode shapes were...

Dynamic properties such as natural frequencies and mode shapes are directly affected by damage in structures. In this paper, changes in natural frequencies and mode shapes were used as the input to various objective functions for damage detection. Objective functions related to natural frequencies, mode shapes, modal flexibility and modal strain energy have been used, and their performances hav...

This paper addresses the fault detection of a cracked cantilever beam using a hybrid artificial intelligence technique. The hybrid technique used here uses a fuzzy-neuro controller. The fuzzy-neuro controller has two parts. The first part is comprised of the fuzzy controller, and the second part is comprised of the neural controller. The input parameters of the fuzzy controller are relative dev...

Buildings with either complex geometric shapes or structural systems with noncoincident centers of mass and resistance, or both, may undergo three-dimensional ~3D! coupled motions when exposed to spatiotemporally varying dynamic wind loads. To capture the dynamic load effects, this paper presents a framework for the analysis of 3D coupled dynamic response of buildings and modeling of the equiva...

Rotating machinery, such as steam turbo, compressor, and aeroengine etc., are widely used in many industrial fields. Among the important rotor faults, the fatigue crack fault, which can lead to catastrophic failure and cause injuries and severe damage to machinery if undetected in its early stages, is most difficult to detect efficiently with traditional methods. In the paper, based on the trut...