scholarly journals Non-Model Approach Based Damage Detection in RC Frame with Masonry Infill

Proceedings ◽  
2018 ◽  
Vol 4 (1) ◽  
pp. 56
Author(s):  
Himakshi Bhatia ◽  
Ajay Chourasia ◽  
Shilpa Pal
Keyword(s):  
Damage Detection ◽  
Damage Identification ◽  
Response Spectra ◽  
Mode Shapes ◽  
Rc Frame ◽  
Scaled Model ◽  
Masonry Infill ◽  
Building Research Institute ◽  
Time Histories ◽  
Modal Curvature

The paper focuses on real-time damage detection based on vibration studies carried out by the Central Building Research Institute (CBRI) structural health monitoring team. The experiment was performed on a 1:3 scaled model of a six- story reinforced concrete (RC) frame with masonry infill in the building dynamics laboratory of CBRI. The forward problem is attended by inducing step-by-step damage in infill to investigate the changes in dynamic response as a result of changes in the physical properties of the structure. Recorded time histories are processed for frequency response spectra (FRS) with fast fourier transform (FFT) and mode shapes are obtained. Changes in natural frequency and modal curvature for each of the five damage cases are analysed for damage detection and location in the structure. An algorithm for damage identification viz. curvature damage factor (CDF) approach is presented.

A Study on Vibration-Based Damage Detection and Location in an Aircraft Wing Scaled Model

2006 ◽  
Vol 3-4 ◽  
pp. 309-314 ◽  
Author(s):  
Irina Trendafilova
Keyword(s):  
Damage Detection ◽  
Natural Frequencies ◽  
Element Model ◽  
Vibration Response ◽  
Mode Shapes ◽  
Aircraft Wing ◽  
Scaled Model ◽  
Damage Location ◽  
Wing Model ◽  
Simplified Finite Element Model

This study investigates the possibilities for damage detection and location using the vibration response of an aircraft wing. A simplified finite element model of an aircraft wing is used to model its vibration response. The model is subjected to modal analysis- its natural frequencies are estimated and the mode shapes are determined. Two types of damage are considered - localised and distributed. The wing model is divided into a number of volumes. The goal of the study is to investigate the possibility to use the vibration response of an aircraft wing and especially its modal characteristics for the purposes of damage detection. So we’ll be trying to find suitable features, which can be used to detect damage and restrict it to one of the introduced volumes. The sensitivity of the modal frequencies of the model to damage in different locations is studied. Some general trends in the behaviour of these frequencies with change of the damage location are investigated. The utilization of the modal frequencies for detecting damage in a certain part of the wing is discussed

Application of Extreme Learning Machine to Damage Detection of Plate-Like Structures

2017 ◽  
Vol 17 (07) ◽  
pp. 1750068 ◽  
Author(s):  
S. S. Kourehli
Keyword(s):  
Damage Detection ◽  
Extreme Learning Machine ◽  
Damage Identification ◽  
Mode Shapes ◽  
Effective Technique ◽  
Plate Structures ◽  
Modal Data ◽  
Plate Elements ◽  
Damage States ◽  
Learning Machine

An effective method for damage detection of plate structures using the extreme learning machine (ELM) is proposed in this study. With the ELM, the mode shapes and natural frequencies of a damaged plate are treated as the input and the damage states in the plate elements as the output. The proposed method was applied to two numerical examples, namely, a cantilever and a plate with four-fixed supports containing one or several damages with and without noise in the modal data. The results obtained reveal that the methodology can be used as an effective technique for the damage identification of plate structures using the modal data and ELM.

Research Based on Modal Curvature and Wavelet Transform for Identifying Damage of Reticulated Shell Structures

2014 ◽  
Vol 501-504 ◽  
pp. 905-910
Author(s):  
Meng Hong Wang ◽  
Chen Meng Ji ◽  
Shan Shan Luo
Keyword(s):  
Wavelet Transform ◽  
Damage Identification ◽  
Shell Structures ◽  
Scaled Model ◽  
Transform Method ◽  
Stiffness Reduction ◽  
Modal Curvature ◽  
Transform Coefficients ◽  
The Difference ◽  
Reticulated Shell Structure

In this paper, a research is carried on to identify damage of reticulated shell structures based on the combination of modal curvature method and wavelets transform method. Take a scaled model of the reticulated shell structure as an example to analyze, the cross section of one member supposed to have a slight damage of stiffness reduction. In order to locate the damage, modal curvatures of the structure are taken as damage indexes to perform continuous wavelet transform. Results of the numerical analysis indicate that the difference of wavelet transform coefficients of modal curvature can be used to locate damage roughly, while the wavelet transform coefficients of modal curvature difference can be used to locate damage more precisely with easier and more reliable data processing. So it is clear that the damage identification based on modal curvature and wavelet transform is quite effective.

scholarly journals DAMAGE IDENTIFICATION IN A PLATE-LIKE STRUCTURE USING MODAL DATA

Aviation ◽  
2013 ◽  
Vol 17 (2) ◽  
pp. 45-51 ◽  
Author(s):  
Sandris Ručevskis ◽  
Andris Chate
Keyword(s):  
Damage Detection ◽  
Mode Shape ◽  
Damage Identification ◽  
Research Effort ◽  
Random Noise ◽  
Simulated Data ◽  
Mode Shapes ◽  
Shape Information ◽  
Detection Algorithms ◽  
Simulated Test

In this paper, an on-going research effort aimed at detecting and localising damage in plate-like structures by using mode shape curvature–based damage detection algorithms is described. Two alternative damage indexes are examined. The first one uses exclusively mode shape curvature data from the damaged structure. This method was originally developed for beam-like structures. In this paper, the method is generalised to plate-like structures that are characterised by two-dimensional mode shape curvature. To examine limitations of the method, several sets of simulated data are applied and damage detection results are compared to the damage identification method that requires mode shape information from both the undamaged and the damaged states of the structure. The modal frequencies and the corresponding mode shapes for the first 15 modes of a plate are obtained via finite element models. Simulated test cases include damage of various levels of severity. In order to ascertain the sensitivity of the proposed method to noisy experimental data, numerical mode shapes are corrupted with different levels of random noise.

scholarly journals Dynamic Identification Techniques to Numerically Detect the Structural Damage

2013 ◽  
Vol 7 (1) ◽  
pp. 43-50 ◽  
Author(s):  
Dora Foti
Keyword(s):  
Finite Element ◽  
Damage Detection ◽  
Structural Damage ◽  
Model Updating ◽  
Element Model ◽  
Mode Shapes ◽  
Dynamic Identification ◽  
Engineering Structures ◽  
Bridge Model ◽  
Modal Curvature

Damage detection in civil engineering structures using changes in measured modal parameters is an area of research that has received notable attention in literature in recent years. In this paper two different experimental techniques for predicting damage location and severity have been considered: the Change in Mode Shapes Method and the Mode Shapes Curvature Method. The techniques have been applied to a simply supported finite element bridge model in which damage is simulated by reducing opportunely the flexural stiffness EI. The results show that a change in modal curvature is a significant damage indicator, while indexes like MAC and COMAC – extensively and correctly used for finite element model updating - lose their usefulness in order to damage detection.

Damage identification in composite laminates using a hybrid method with wavelet transform and finite element model updating

2017 ◽  
Vol 232 (5) ◽  
pp. 815-827 ◽  
Author(s):  
Mohammad-Reza Ashory ◽  
Ahmad Ghasemi-Ghalebahman ◽  
Mohammad-Javad Kokabi
Keyword(s):  
Genetic Algorithm ◽  
Wavelet Transform ◽  
Damage Detection ◽  
Composite Laminates ◽  
Strain Energy ◽  
Damage Identification ◽  
Model Updating ◽  
Error Function ◽  
Composite Plates ◽  
Mode Shapes

Delamination is a common defect in composite plates that may cause significant losses in commercial applications. In this study, a hybrid damage detection method was introduced, which raised both the damage identification sensitivity level and detected quantitative damage parameters. The primary damage location was pinpointed by the wavelet transform, and the damage parameters, including location, depth, and intensity, were then isolated by the model updating process. The wavelet transform was obtained according to the signal’s nature, which leads to improvement in the wavelet transform’s operation. Then, the lifting scheme algorithm process was performed to increase the wavelet efficiency in damage detection. In addition, a proper signal, based on strain energy, was used for damage detection by the wavelet transform. Finally, the genetic algorithm method was employed in the proposed model updating method to identify the damage parameters through employing a novel error function. The selected error function was based on strain energy, having the best operation among previously identified modal criteria. Consequently, the accuracy of identifying the damage parameters was improved upon utilizing the proposed method, particularly in the presence of noise. In addition, the solution performed faster than the previously available updating methods which utilized only the genetic algorithm-based on mode shapes and natural frequencies for detecting the damage.

Statistics-Based Noise Analysis for Vibration-Based Damage Identification

2006 ◽  
Author(s):  
L. Yu ◽  
T. Yin ◽  
H. P. Zhu
Keyword(s):  
Damage Detection ◽  
Structural Damage ◽  
Damage Identification ◽  
Perturbation Technique ◽  
Random Perturbation ◽  
Noise Analysis ◽  
Detection Methods ◽  
Mode Shapes ◽  
Composite Function ◽  
Analysis Technique

As the vibration-based structural damage detection methods are easily affected by the environmental noise, a novel noise analysis method is proposed based on the statistics in this paper together with the Monte Carlo technique for assessing the influence of experimental noise of modal data on sensitivity-based damage detection methods. Different from the commonly used random perturbation technique, the proposed technique is deduced directly by the Moore–Penrose generalized inverse of sensitivity matrix under the differential quotient rule of composite function. It can not only make the analysis process more effective but also analyze the noise influence on both frequencies and mode shapes in a similar way. Furthermore, an improved modal sensitivity based damage detection method is also proposed and compared with other two commonly used sensitivity-based methods in this paper. A one-story portal frame is adopted to evaluate the efficiency of both the proposed noise analysis technique and the improved modal sensitivity based method. The assessment results show that the proposed statistics-based noise analysis technique is effective and more suitable for the vibration-based damage identification. The improved modal sensitivity based method is more robust to noise than the other commonly used sensitivity-based methods.

A State-of-the-Art Review on FRF-Based Structural Damage Detection: Development in Last Two Decades and Way Forward

2021 ◽  
Author(s):  
Saranika Das ◽  
Koushik Roy
Keyword(s):  
Damage Detection ◽  
Structural Damage ◽  
Damage Identification ◽  
Excitation Frequency ◽  
Mode Shapes ◽  
Computational Time ◽  
Structural Damage Detection ◽  
Monitoring Methods ◽  
Detection Techniques ◽  
Noise Contamination

Vibration-based damage detection techniques receive wide attention of the research community in recent years to overcome the limitations of conventional structural health monitoring methods. The modal parameters, namely, natural frequencies, mode shapes, transmissibility, frequency response function (FRF), and other damage sensitive features are usually employed to identify damage in a structure. The main objective of this review is to generate a detailed understanding of FRF-based techniques and to study their performance in terms of advantage, accuracy, and limitations in structural damage detection. This paper also reviews various approaches to develop methodologies in terms of efficiency and computational time. The study observed that excitation frequency, location of application of excitation, type of sensor, number of measurement locations, noise contamination in FRF data, selection of frequency range for simulation, weighting and numerical techniques to solve the over-determined set of equations influence the effectiveness of damage identification procedure. Limitations and future prospects have also been addressed in this paper. The content of this paper aims to guide researchers in developing formulations, updating models, and improving results in the field of FRF-based damage identification.

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