PSI - Issue 18

Available online at www.sciencedirect.com Structural Integrity Procedia 00 (2019) 000–000 Available online at www.sciencedirect.com ScienceDirect Structural Integrity Procedia 00 (2019) 000–000 Available online at www.sciencedirect.com ScienceDirect

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Procedia Structural Integrity 18 (2019) 843–848

25th International Conference on Fracture and Structural Integrity Application the acoustic emission technique to investigation of damage initiation in composites Ekaterina M. Zubova a *, Tatyana V. Tretyakova a , Valery E. Wildemann a a Centre of Experimental Mechanics, Perm National Research Polytechni с University, 29 Komsomolsky AVE, Perm 614000, Russia Abstract In many areas of industry, the replacement from metals to composites is carried out in order to reduce the weight of structures and increase their performance. The widespread use of composite materials in critical structures necessitates a more detailed study of the deformation processes, damage accumulation and failure in order to timely detect defects do not indicate necessarily a critical condition of a structure or loss of its structural integrity, but necessarily a decrease in its bearing capacity. The aim of work is devoted to experimental study of damage accumulation in carbon fiber reinforced polymer composites at the initial stage of loading by using the acoustic emission technique. Using this method, it is possible to detect growing and, therefore, the most dangerous defects and obtaining additional valuable information about the behavior of materials under load. 25th International Conference on Fracture and Structural Integrity Application the acoustic emission technique to investigation of damage initiation in composites Ekaterina M. Zubova a *, Tatyana V. Tretyakova a , Valery E. Wildemann a a Centre of Experimental Mechanics, Perm National Research Polytechni с University, 29 Komsomolsky AVE, Perm 614000, Russia Abstract I many ar as of industry, the replac ment from metals to composites is carried out in order to reduce the weight of structures and increase their performance. The widespread use of composite materials in critical structures necessitates a more det iled study of the ef rmation processes, damage accumulation and failure in order to timely d tect defects do ot indi ate nec ssarily a critical condition of a structure or loss of its structural integrity, but necessarily a decrease in its bearing capacity. The aim of work is devoted to experimental study of damage accumulation in carbon fiber reinforce polymer composites at the initial stage of loading by using the acoustic emission technique. Using this method, it is possible to detect growing and, therefore, the most dangerous defects and obtaining additional valuable information about the behavior of materials under load.

© 2019 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the Gruppo Italiano Frattura (IGF) ExCo. © 2019 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the Gruppo Italiano Frattura (IGF) ExCo. © 2019 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the Gruppo Italiano Frattura (IGF) ExCo.

Keywords: Carbon fiber reinforced polymer composites, damage initiation, acoustic emission, mechanical test, uniaxial tension. Keywords: Carbon fiber reinforced polymer composites, damage initiation, acoustic emission, mechanical test, uniaxial tension.

1. Introduction The destruction of fibrous composites is a complex multi-step process starting long before the final failure. In the early loading step, the composite material consisting of a matrix and reinforcing fibers, accumulates scattered damages associated with the growth of defects at the molecular level and then at the level of structural elements. At some time, the damage density reaches a critical level, the nature of the process changes and large cracks appear. As a result of the merger of such large cracks, the structure integrity is lost and the composite is failure. 1. Introduction The destruction of fibrous composites is a complex multi-step process starting long before the final failure. In the early loading step, the composite material consisting of a matrix and reinforcing fibers, accumulates scattered damages associated with the growth of defects at the molecular level and then at the level of structural elements. t some time, the damage density reaches a critical level, the nature of the process changes and large cracks appear. As a result of the merger of such large cracks, the structure integrity is lost and the composite is failure.

2452-3216 © 2019 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the Gruppo Italiano Frattura (IGF) ExCo. 2452-3216 © 2019 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the Gruppo Italiano Frattura (IGF) ExCo. * Correspon ing author. Tel.: +7-909-72-95-995; fax: +7-342-219-8732. E-mail address: cem.zubova@mail.ru * Corresponding author. Tel.: +7-909-72-95-995; fax: +7-342-219-8732. E-mail address: cem.zubova@mail.ru

2452-3216  2019 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the Gruppo Italiano Frattura (IGF) ExCo. 10.1016/j.prostr.2019.08.234