Structural crack identification method based on dynamic distributed strain monitoring

2020 ◽  
Author(s):  
Wenjing Wu ◽  
Xin Feng ◽  
Farhad Ansari
Keyword(s):  
Crack Identification ◽  
Identification Method ◽  
Strain Monitoring ◽  
Distributed Strain

Effect of a breathing crack on the damping changes in nonlinear vibrations of a cracked beam: Experimental and theoretical investigations

2020 ◽  
pp. 107754632096031
Author(s):  
Masoud Kharazan ◽  
Saied Irani ◽  
Mohammad Ali Noorian ◽  
Mohammad Reza Salimi
Keyword(s):  
Nonlinear Vibrations ◽  
Crack Depth ◽  
Beam Theory ◽  
Experimental Tests ◽  
Damping Coefficient ◽  
Crack Identification ◽  
Breathing Crack ◽  
Cracked Beam ◽  
Identification Method ◽  
Nonlinear Crack

The attempts to identify damping changes in a cracked beam can improve the accuracy of the nonlinear crack identification method. For the purpose of this aim, a parametric nonlinear equation of motion is obtained using the Euler–Bernoulli beam theory and parametric nonlinear breathing crack assumptions. Several experiments were conducted to identify the effect of breathing cracks on changing the damping value in nonlinear vibrations of a cracked beam. Experimental tests have revealed that increasing the crack depth and the level of excitation enlarges the damping coefficient in a vibrating beam. For this reason, the effects of the excitation force and crack depth on the structural damping coefficient are investigated. The obtained results indicated that considering the nonlinear response of a cracked beam and measuring the value of the damping changes can significantly improve the accuracy of the nonlinear crack identification method.

Distributed strain monitoring of two-way slabs

2019 ◽  
Vol 189 ◽  
pp. 580-588
Author(s):  
Sara Nurmi ◽  
Neil A. Hoult ◽  
Simon D. Howell
Keyword(s):  
Strain Monitoring ◽  
Distributed Strain

scholarly journals A Crack Identification Method for Bridge Type Structures under Vehicular Load Using Wavelet Transform and Particle Swarm Optimization

2013 ◽  
Vol 2013 ◽  
pp. 1-10 ◽  
Author(s):  
Hakan Gökdağ
Keyword(s):  
Particle Swarm Optimization ◽  
Wavelet Transform ◽  
Particle Swarm ◽  
Dynamic Responses ◽  
Crack Identification ◽  
Discrete Wavelet ◽  
Swarm Optimization ◽  
Coupled Equations ◽  
Identification Method ◽  
Bridge Type

In this work a crack identification method is proposed for bridge type structures carrying moving vehicle. The bridge is modeled as an Euler-Bernoulli beam, and open cracks exist on several points of the beam. Half-car model is adopted for the vehicle. Coupled equations of the beam-vehicle system are solved using Newmark-Beta method, and the dynamic responses of the beam are obtained. Using these and the reference displacements, an objective function is derived. Crack locations and depths are determined by solving the optimization problem. To this end, a robust evolutionary algorithm, that is, the particle swarm optimization (PSO), is employed. To enhance the performance of the method, the measured displacements are denoised using multiresolution property of the discrete wavelet transform (DWT). It is observed that by the proposed method it is possible to determine small cracks with depth ratio 0.1 in spite of 5% noise interference.

Crack Position and Depth Identification in Rotating Shafts: Part 2 — Experimental Results

2005 ◽  
Author(s):  
Nicolo` Bachschmid ◽  
Paolo Pennacchi ◽  
Ezio Tanzi
Keyword(s):  
Dynamical Behavior ◽  
Industrial Applications ◽  
Experimental Results ◽  
Crack Identification ◽  
Identification Method ◽  
Different Types ◽  
Rotating Shafts ◽  
Short Time ◽  
Crack Position ◽  
Deep Crack

This paper presents the experimental validation of a model based transverse crack identification method suitable for industrial machines, described in part 1. The method is validated by experimental results obtained on two test rigs, which were expressly designed for investigating the dynamical behavior of cracked horizontal rotors. On the first test rig, only one crack type is considered, while on the second one three different types of crack have been analyzed: the first is a slot, therefore not actually a crack since it has not the typical breathing behavior, the second a small crack (14% of the diameter) and the third a deep crack (47% of the diameter). The excellent accuracy obtained in identifying position and depth of different cracks proves the effectiveness and reliability of the proposed method. Moreover, the implementation of identification method operates on a PC and takes short time to run, therefore is suitable for industrial applications.

Sign in / Sign up

Export Citation Format

Share Document