Application of the Higher Modes to Crack Identification in a Cantilever Beam

2007 ◽  
Vol 347 ◽  
pp. 595-600 ◽  
Author(s):  
Yu Xiang Liu ◽  
Wei Wei Zhang ◽  
Hong Wei Ma
Keyword(s):  
Wavelet Transform ◽  
Adverse Effects ◽  
Damage Detection ◽  
Crack Detection ◽  
Vibration Mode ◽  
Crack Identification ◽  
Vibration Modes ◽  
Fundamental Vibration ◽  
Higher Modes

Damage detection by the wavelet transform of the fundamental vibration mode receives much attention recently. However, the higher vibration modes were hardly discussed in past literatures. As we know they are more sensitive to the crack comparing with the fundamental mode, which bring abundant damage information. The objective of this study is to show that the first four modes are available using wavelet transform for crack parameter identification. Specially, using the higher mode could result in an excellent quality of crack identification when the mode data was contaminated by noise. But too higher modes have possibly adverse effects on the quality of crack detection.

Comparative Studies on Damage Detection Based on Dynamic Response of a Beam Subjecting to Moving Load

2013 ◽  
Vol 330 ◽  
pp. 925-930
Author(s):  
Wei Wei Zhang ◽  
Hong Wei Ma
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Wavelet Transform ◽  
Damage Detection ◽  
Comparative Studies ◽  
Moving Load ◽  
Dynamic Responses ◽  
Simply Supported ◽  
Velocity Response

In this paper, the feasibility and sensitivity of damage detection based on dynamic responses of a simply supported beam were examined theoretically and numerically, which were the displacement, velocity and acceleration histories at mid-span on a beam under the moving load. First, the theoretic background of a damage beam vibration subjecting to moving load was briefly described. And then a finite element method was used to calculate the responses of the beam. Using wavelet transform of the dynamic responses, the damage could be identified. Case studies showed that the velocity response was sensitive to the damage and the simulations illustrated the better quality of damage detection by velocity than the ones by displacement and acceleration.

Numerical Studies on Wavelet-Based Crack Detection Based on Velocity Response of a Beam Subjecting to Moving Load

2013 ◽  
Vol 569-570 ◽  
pp. 854-859 ◽  
Author(s):  
Wei Wei Zhang ◽  
Jia Geng ◽  
Zi Long Zhao ◽  
Zhi Hua Wang
Keyword(s):  
Wavelet Transform ◽  
Damage Detection ◽  
Crack Detection ◽  
Moving Load ◽  
Noise Tolerance ◽  
Simply Supported Beam ◽  
Simply Supported ◽  
Damage Location ◽  
Numerical Studies ◽  
Velocity Response

In this paper, the possibility and validity of damage detection based on velocity response of a simply supported beam under the moving load are examined theoretically and numerically. It includes the following parts: First, the theoretic background of the beam vibration subjecting to moving load is briefly described. And then, the velocity responses of a simple supported beam are calculated by software Ansys. Using wavelet transform, the damage location can be identified successfully. At last, the effects of noise and load speed are discussed in detail. Numerical studies show the validity of the proposed method and a good noise tolerance using the velocity response.

Status of nondestructive control of transport function metal products at JSC EVRAZ NTMK

2020 ◽  
Vol 76 (6) ◽  
pp. 586-590
Author(s):  
S. P. Bersenev ◽  
E. M. Slobtsova
Keyword(s):  
Crack Detection ◽  
Middle Part ◽  
Control Line ◽  
Magnetic Powder ◽  
Nondestructive Control ◽  
Automated Control ◽  
Ultrasonic Control ◽  
Acoustic Contact ◽  
In Series

Achievements in the area of automated ultrasonic control of quality of rails, solid-rolled wheels and tyres, wheels magnetic powder crack detection, carried out at JSC EVRAZ NTMK. The 100% nondestructive control is accomplished by automated control in series at two ultrasonic facilities RWI-01 and four facilities УМКК-1 of magnetic powder control, installed into the exit control line in the wheel-tyre shop. Diagram of location, converters displacement and control operations in the process of control at the facility RWI-01 presented, as well as the structural diagram of the facility УМКК-1. The automated ultrasonic control of rough tyres is made in the tyres control line of the wheel-tyre shop at the facility УКБ-1Д. The facility enables to control internal defects of tyres in radial, axis and circular directions of radiation. Possibilities of the facility УКБ-1Д software were shown. Nondestructive control of railway rails is made at two facilities, comprising the automated control line of the rail and structural shop. The УКР-64Э facility of automated ultrasonic rails control is intended to reveal defects in the area of head, web and middle part of rail foot by pulse echo-method with a immersion acoustic contact. The diagram of rail P65 at the facility УКР-64Э control presented. To reveal defects of the macrostructure in the area of rail head and web by mirror-shadow method, an ultrasonic noncontact electromagnetic-acoustic facility is used. It was noted, that implementation of the 100% nondestructive control into the technology of rolled stuff production enabled to increase the quality of products supplied to customers and to increase their competiveness.

Cytoprotective Agents to Avoid Chemotherapy Induced Sideeffects on Normal Cells: A Review

2019 ◽  
Vol 19 (10) ◽  
pp. 765-781
Author(s):  
Seema Rohilla ◽  
Harish Dureja ◽  
Vinay Chawla
Keyword(s):  
Adverse Effects ◽  
Anticancer Agents ◽  
Therapeutic Index ◽  
Chemotherapeutic Agents ◽  
Vital Role ◽  
Normal Cells ◽  
Normal Tissues ◽  
Organ Specific ◽  
Delay In Treatment

Anticancer agents play a vital role in the cure of patients suffering from malignancy. Though, the chemotherapeutic agents are associated with various adverse effects which produce significant toxic symptoms in the patients. But this therapy affects both the malignant and normal cells and leads to constricted therapeutic index of antimalignant drugs which adversely impacts the quality of patients’ life. Due to these adversities, sufficient dose of drug is not delivered to patients leading to delay in treatment or improper treatment. Chemoprotective agents have been developed either to minimize or to mitigate the toxicity allied with chemotherapeutic agents. Without any concession in the therapeutic efficacy of anticancer drugs, they provide organ specific guard to normal tissues.

Singular Values Decomposition and Lifting Wavelet Transform for Speech Signal Embedding into Digital Image

2019 ◽  
Vol 12 (2) ◽  
pp. 138-151
Author(s):  
Mourad Talbi ◽  
Med Salim Bouhlel
Keyword(s):  
Wavelet Transform ◽  
Speech Signal ◽  
Signal To Noise Ratio ◽  
Perceptual Quality ◽  
Lifting Wavelet Transform ◽  
Signal To Noise ◽  
Perceptual Evaluation ◽  
Lifting Wavelet ◽  
Noise Ratio

Background: In this paper, we propose a secure image watermarking technique which is applied to grayscale and color images. It consists in applying the SVD (Singular Value Decomposition) in the Lifting Wavelet Transform domain for embedding a speech image (the watermark) into the host image. Methods: It also uses signature in the embedding and extraction steps. Its performance is justified by the computation of PSNR (Pick Signal to Noise Ratio), SSIM (Structural Similarity), SNR (Signal to Noise Ratio), SegSNR (Segmental SNR) and PESQ (Perceptual Evaluation Speech Quality). Results: The PSNR and SSIM are used for evaluating the perceptual quality of the watermarked image compared to the original image. The SNR, SegSNR and PESQ are used for evaluating the perceptual quality of the reconstructed or extracted speech signal compared to the original speech signal. Conclusion: The Results obtained from computation of PSNR, SSIM, SNR, SegSNR and PESQ show the performance of the proposed technique.

scholarly journals Extended adverse effects of cyclophosphamide on mouse ovarian function

2021 ◽  
Vol 22 (1) ◽  
Author(s):  
Jihyun Kim ◽  
Sooseong You
Keyword(s):  
Adverse Effects ◽  
Cancer Survivors ◽  
Cancer Survival ◽  
Ovarian Function ◽  
Treatment Options ◽  
Bioinformatics Analyses ◽  
Hormonal Stimulation ◽  
Patients With Cancer ◽  
Multiple Exposures

Abstract Purpose Most patients with cancer undergo multiple administrations of anticancer drugs during treatment, resulting in chronic impairment of their reproductive health. As improved treatment options increase cancer survival, it has become increasingly important to address fertility issues in cancer survivors. In this study, we examined the pathophysiological effects of multiple exposures to cyclophosphamide (Cy) on the ovaries of mice and their underlying molecular mechanism. Methods Female C57BL/6 mice were intraperitoneally injected with 100 mg/kg Cy six times over 2 weeks; 4 weeks later, the mice were sacrificed and their ovaries, sera, and oocytes were collected for histological observation, measurement of anti-Müllerian hormone levels, and assessment of oocyte quantity and quality in response to hormonal stimulation. Gene expression changes in Cy-treated ovaries were examined by microarray and bioinformatics analyses. Results After repeated Cy exposure, the anti-Müllerian hormone level was decreased, and follicle loss and impairments in the quality of oocyte were irreversible. The expression levels of genes involved in folliculogenesis, oogenesis, and zona pellucida glycoprotein transcription displayed sustained alterations in Cy-exposed ovaries even after 4 weeks. Conclusion The adverse effects of Cy on ovarian function and oocytes remained even after chemotherapy was complete. Therefore, strategies to prevent ovarian damage or restore ovarian function after treatment are required to safeguard the fertility of young cancer survivors.

Identifying VIV Vibration Modes by Use of the Empirical Orthogonal Functions Technique

2002 ◽  
Author(s):  
Gudmund Kleiven
Keyword(s):  
Model Test ◽  
Vibration Mode ◽  
Multivariate Data ◽  
Empirical Orthogonal Functions ◽  
Mode Shapes ◽  
Data Sets ◽  
Vibration Modes ◽  
Ocean Engineering ◽  
Orthogonal Functions ◽  
Related Technique

The Empirical Orthogonal Functions (EOF) technique has widely being used by oceanographers and meteorologists, while the Singular Value Decomposition (SVD being a related technique is frequently used in the statistics community. Another related technique called Principal Component Analysis (PCA) is observed being used for instance in pattern recognition. The predominant applications of these techniques are data compression of multivariate data sets which also facilitates subsequent statistical analysis of such data sets. Within Ocean Engineering the EOF technique is not yet widely in use, although there are several areas where multivariate data sets occur and where the EOF technique could represent a supplementary analysis technique. Examples are oceanographic data, in particular current data. Furthermore data sets of model- or full-scale data of loads and responses of slender bodies, such as pipelines and risers are relevant examples. One attractive property of the EOF technique is that it does not require any a priori information on the physical system by which the data is generated. In the present paper a description of the EOF technique is given. Thereafter an example on use of the EOF technique is presented. The example is analysis of response data from a model test of a pipeline in a long free span exposed to current. The model test program was carried out in order to identify the occurrence of multi-mode vibrations and vibration mode amplitudes. In the present example the EOF technique demonstrates the capability of identifying predominant vibration modes of inline as well as cross-flow vibrations. Vibration mode shapes together with mode amplitudes and frequencies are also estimated. Although the present example is not sufficient for concluding on the applicability of the EOF technique on a general basis, the results of the present example demonstrate some of the potential of the technique.

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