scholarly journals Entropy-Based Structural Health Monitoring System for Damage Detection in Multi-Bay Three-Dimensional Structures

Entropy ◽  
2018 ◽  
Vol 20 (1) ◽  
pp. 49 ◽  
Author(s):  
◽  
Keyword(s):  
Structural Health Monitoring ◽  
Damage Detection ◽  
Monitoring System ◽  
Health Monitoring ◽  
Three Dimensional ◽  
Health Monitoring System ◽  
Structural Health ◽  
Structural Health Monitoring System

Computation of Wave Propagation in Damped Specimen for Damage Detection

2014 ◽  
Vol 783-786 ◽  
pp. 2296-2301 ◽  
Author(s):  
Veena Jawali ◽  
Prakash Parasivamurthy ◽  
Ashwini Nagesh
Keyword(s):  
Structural Health Monitoring ◽  
Damage Detection ◽  
Monitoring System ◽  
Health Monitoring ◽  
Time Of Flight ◽  
Source Location ◽  
Wave Source ◽  
Health Monitoring System ◽  
Structural Health ◽  
Structural Health Monitoring System

Aim of a structural health monitoring system must be to collect sufficient information about the damage for appropriate remedial measures to be taken to ensure safety. The preliminary step in the process of damage assessment is locating the damage .One of the challenges faced by the structural health monitoring system is monitoring in-flight damages. Localization of in-flight damages or sudden impacts can be achieved by monitoring the acoustic emissions in real time mode. In this paper, an approach based on the employment of Piezo-electric transducer rosettes to locate the acoustic emission source in an aluminum plate is presented. Using the strain gage rosette concepts adapted for piezoelectric transducers, the wave strain principal angles are determined. When two rosettes are used, the intersection of the principal wave strain directions detected by the rosettes gives the wave source location. The method does not require the knowledge of wave velocity in the medium in contrast to the time of flight based location. Hence, this technique can be used in anisotropic or complex structures where the source localization using the conventional time of flight method is difficult. The principal strain angle using the voltage response of the transducers and the rosette principles are obtained and the co-ordinates of the wave source location are calculated using the co-ordinates of the centroids of the rosettes in MATLAB.According to the tests, the rosette piezo-transducer outperforms the single piezo elements to a degree justifying its complexity. The rosette piezo transducer provides more damage related information compared to single elements and hence the performance of the damage detection system can be significantly improved if rosettes are used.

scholarly journals Validation of a procedure for the evaluation of the performance of an installed structural health monitoring system

2018 ◽  
Vol 18 (5-6) ◽  
pp. 1557-1568 ◽  
Author(s):  
Sebastian Heinlein ◽  
Peter Cawley ◽  
Thomas Vogt
Keyword(s):  
Finite Element ◽  
Structural Health Monitoring ◽  
Damage Detection ◽  
Monitoring System ◽  
Health Monitoring ◽  
Complex Structure ◽  
Detection Ability ◽  
Health Monitoring System ◽  
Structural Health ◽  
Structural Health Monitoring System

Validation of the performance of guided wave structural health monitoring systems is vital if they are to be widely deployed; testing the damage detection ability of a system by introducing different types of damage at varying locations is very costly and cannot be performed on a system in operation. Estimating the damage detection ability of a system solely by numerical simulations is not possible as complex environmental effects cannot be accounted for. In this study, a methodology was tested and verified that uses finite element simulations to superimpose defect signals onto measurements collected from a defect-free structure. These signals are acquired from the structure of interest under varying environmental and operational conditions for an initial monitoring period. Measurements collected in a previous blind trial of an L-shaped pipe section, onto which a number of corrosion-like defects were introduced, were utilised during this investigation. The growth of three of these defects was replicated using finite element analysis and the simulated reflections were superimposed onto signals collected on the defect-free test pipe. The signal changes and limits of reliable detection predicted from the synthetic defect reflections superimposed on the measurements from the undamaged complex structure agreed well with the changes due to real damage measured on the same structure. This methodology is of great value for any structural health monitoring system as it allows for the minimum detectable defect size to be estimated for specific geometries and damage locations in a quick and efficient manner without the need for multiple test structures while accounting for environmental variations.

An Automated Structural Health Monitoring System

2011 ◽  
Author(s):  
Zeaid Hasan ◽  
Fares Hasweh ◽  
Omar Abu Al-Nadi ◽  
Ghassan Atmeh
Keyword(s):  
Structural Health Monitoring ◽  
Damage Detection ◽  
Monitoring System ◽  
Health Monitoring ◽  
Fiber Composites ◽  
Current Time ◽  
Health Monitoring System ◽  
Structural Health ◽  
Structural Health Monitoring System ◽  
Piezoelectric Fiber

Structural health monitoring (SHM) is the process of implementing a damage identification strategy which can be utilized in several applications including aerospace, civil and mechanical engineering infrastructure. Damage is defined as changes to the material and/or geometric properties of these systems. These changes adversely affect the current or future performance of the system. In order to identify damage in a suitable and meaningful manner, the damaged state is compared with other usually undamaged states. This study focuses on a structural health monitoring (SHM) system based on detecting shifts in natural frequencies of the structure. This structural health monitoring system incorporates a low power wireless transmitter that sends a warning signal when damage is detected in a structure. The damage detection technique is implemented on composite structures which are widely used in many applications including aeronautical and aerospace. An automated damage detection system capable of providing information of damage locations based on the finite element analysis and able to compare damage events to other historical data is also proposed in this paper and initially implemented using a microcontroller chip. Moreover, a control methodology using piezoelectric fiber composites, such as active fiber composites (AFCs) and microfiber composites (MFCs), is included as part of the system for vibration suppression purposes. The advantages of using piezoelectric fiber composite actuators are their high performance, flexibility, and durability when compared with the traditional piezoceramic (PZT) actuators. The proposed system may be implemented in many structural components such as aircraft frames and bridges. This SHM technology may help replace the current time-based maintenance scheme with a condition-based one. The condition-based maintenance scheme relies on the ability to monitor the condition of the system and supply information of damage detection to allow a corrective action to be taken.

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