عنوان مقاله [English]
نویسندگان [English]چکیده [English]
Composite applications are very wide in most industrial fields. Today, polymer matrix composites are used in the automotive industry, aerospace, oil, gas and petrochemical Industries and etc. Glass / epoxy composite is one of the most useful composites that has special properties such as high strength-to-weight ratio, high hardness, high corrosion resistance, low thermal expansion, resistance to nuclear radiation and absorption of energy. Composite beams may be used as flexural elements. In flexural loading, the crack initiation and failure can occur in a variety of modes that each ones has special frequencies. In this research, acoustic emission method was used to evaluate and check the different failure mechanisms of glass epoxy composite beam under three point bending loading. In order to determine different failure mechanisms, wavelet transform analysis was used for acoustic signal processing by using only one sensor. Three types of dominant failure mechanisms (matrix fracture, debonding and fiber breakage) in composite beam under bending were identified and the frequency ranges corresponding to these failure mechanisms were determined. Wavelet transform results showed that these three types of dominant failure mechanisms (matrix fracture, debonding and fiber breakage) have frequency ranges of 0-125 KHz, 125-250 KHz and 375-500 KHz respectively. Finally, the observations of scanning electron microscope from fracture surface of specimen validated the obtained results. This research showed the possibility of acoustic emission technique as a monitoring tool of glass/epoxy composite beam in flexural failure.
 Khamedi, R., M. Nikmehr. "Identification of effects of Nylon nanofibers in carbon- epoxy composite properties by Acoustic Emission." Modares Mechanical Engineering, 2015, Vol. 15, No. 4, pp. 355-360, (In Persian).
 Fotouhi, M., F. Pashmforoush, V. Shokri, M. Ahmadi. "Investigation of damage mechanisms during delamination in composites by use of Wavelet Transform." 3rd International Conference on Manufacturing Engineering, 2011, Tehran, Iran, (In Persian).
 Hajikhani, M., B. Soltannia, A. R. Oskouei, M. Ahmadi, M. "Monitoring of delamination in composites by use of Acoustic Emission." 3rd Condition Monitoring & Fault Diagnosis Conference, 2009, Tehran, Iran, (In Persian).
 Amenabar, I., A. Mendikute, A. López-Arraiza, M. Lizaranzu, J. Aurrekoetxea. "Comparison and analysis of non-destructive testing techniques suitable for delamination inspection in wind turbine blades." Composites Part B: Engineering, 2011, Vol. 42, No. 5, pp. 1298-1305.
 Saeedifar, M., M. Fotouhi, R. Mohammadi, M. Ahmadi Najafabadi, H. Hosseini Toudeshky. "Investigation of delamination and interlaminar fracture toughness assessment of Glass/Epoxy composite by acoustic emission." Modares Mechanical Engineering, 2014, Vol. 14, No. 4, pp. 1-11, (In Persian).
 Shahri, M. N., J. Yousefi, M. Hajikhani, M. Ahmadi. "Investigation of delamination in composite materials using acoustic emission." 19rd National Conference on Manufacturing Engineering, 2010, Tabriz, Iran, (In Persian).
 Uenoya, T. "Acoustic emission analysis on interfacial fracture of laminated fabric polymer matrix composites." Journal of acoustic emission, 1995, Vol. 13, No. 3-4, pp. 95-102.
 Barre, S., M. Benzeggagh. “On the use of acoustic emission to investigate damage mechanisms in glass-fiber-reinforced polypropylene.” Composites Science and Technology, 1994, Vol. 52, No. 3, pp. 369-376.
 Guerjouma, R. E, J. C. Baboux, D. Ducret, N. Godin, P. Guy, S. Huguet, Y. Jayet, T. Monnier. "Non-destructive evaluation of damage and failure of fiber reinforced polymer composites using ultrasonic waves and acoustic emission." Advanced engineering materials, 2001, Vol. 3, No. 8.
 Yoon, D. J., W. J. Weiss, S. P. Shah. "Assessing damage in corroded reinforced concrete using acoustic emission." Journal of engineering mechanics, 2000, Vol. 126, No. 3, pp. 273-283.
 Woo, S. C., N. S. Choi. "Analysis of fracture process in single-edge-notched laminated composites based on the high amplitude acoustic emission events." Composites science and technology, 2007, Vol. 67, No. 7, pp. 1451-1458.
 Godin, N., S. Huguet, R. Gaertner, L. Salmon. "Clustering of acoustic emission signals collected during tensile tests on unidirectional glass/polyester composite using supervised and unsupervised classifiers." NDT&E International, 2007, Vol. 37, pp. 253–264.
 Godin, N., S. Huguet, R. Gaertner. "Integration of the Kohonen’s self organising map and k-means algorithm for the segmentation of the AE data collected during tensile tests on cross-ply composites." NDT&E International, 2005, Vol. 38, pp. 299–309.
 Ni, Q. Q., E. Jinen. "Fracture behavior and acoustic emission in bending tests on single-fiber composites." Engineering fracture mechanics, 1997, Vol. 56, No. 6, pp. 779-796.
 Yousefi, J., M. Ahmadi, M. N. Shahri, A. R. Oskouei, F. J. Moghadas. "Damage Categorization of Glass/Epoxy Composite Material under Mode II Delamination Using Acoustic Emission Data: A Clustering Approach to Elucidate Wavelet Transformation Analysis." Arabian Journal for Science and Engineering, 2013, pp. 1-11.
 Arumugam, V., C. S. Kumar, C. Santulli, F. Sarasini, A. J. Stanley, "Identification of Failure Modes in Composites from Clustered Acoustic Emission Data Using Pattern Recognition and Wavelet Transformation." Arabian Journal for Science and Engineering, 2012, Vol. 38, No. 5, pp. 1087-1102.
 Guo, Y. B., S. C. Ammula. "Real-time acoustic emission monitoring for surface damage in hard machining." International journal of Machine Tools & Manufacture, 2005, Vol. 45, pp. 1622-1627.
 Zarif Karimi, N., H. Heidary, M. Ahmadi, A. Rahimi, M. Farajpur. "Monitoring of residual tensile strength in drilled composite laminates by acoustic emission." Modares Mechanical Engineering, 2014, Vol. 13, No. 15, pp. 169-183, (In Persian).
 Marec, A., J. H. Thomas, R. EI. Guerjouma. “Damage characterization of polymer-based composite materials: Multivariable analysis and wavelet transform for clustering acoustic emission data.” Mechanical Systems and Signal Processing, 2008, Vol. 22, pp. 1441-1464.
 Ni, Q. Q., M. Iwamoto. "Wavelet transform of acoustic emission signals in failure of model composites." Engineering Fracture Mechanic, 2002, 69, pp. 717-728.
 Soman, K. P., K. I. Ramachandran. "Insight into Wavelets from Theory to Practice." 2nd Ed, Prentice-Hall of India Pvt. Limited, 2005.
 Fotouhi, M. "Investigation of delamination in composite materials during drilling using acoustic emission", MSc Thesis, Mechanical Engineering, Amirkabir University, Tehran, 2011, (In Persian).
 Saeedifar, M., M. Fotouhi, R. Mohammadi, M. Ahmadi Najafabadi, M. Hajikhani. "Classification of damage mechanisms during delamination growth in sandwich composites by acoustic emission." Modares Mechanical Engineering, 2014, Vol. 14, No. 6, pp. 144-152, (In Persian).
 Oskouei, A. R., M. Ahmadi. "Acoustic Emission Characteristics of Mode I Delamination in Glass/Polyester Composites." Journal of Composite Materials, 2010, Vol. 44, No. 7, pp. 793-807.
 M. Saeedifar, M. Fotouhi, R. Mohammadi, M. Ahmadinajafabadi, M. Hajikhani. “Classification of damage mechanisms during delamination growth in sandwich composites by acoustic emission.” Modares Mechanical Engineering, 2014, Vol. 14, No. 6, pp. 144-152, (In Persian)
 Fotouhi, M., H. Heidary, M. Ahmadi, F. Pashmforoush. “Characterization of composite materials damage under quasi-static three-point bending test using wavelet and fuzzy C-means clustering.” Journal of Composite Materials, Vol. 10, pp. 1-14, 2012.