Effect of lay-up orientation on fracture toughness of CFRP laminates

Date

2018-12-01

Author

Yavuz, Burak Ogun
Çöker, Demirkan
Parnas, Kemal Levend

Metadata

Show full item record

Item Usage Stats

149
views

0
downloads

Delamination in advanced composites, which causes reduction in the laminate strength, has been a continuing problem. Since it is relatively easier to manufacture, the general practice for the fracture toughness is to conduct tests with 0//0 interface and use these experimental values in the analyses. However, the fracture toughness values are known to vary for different angle interfaces. This happens to be a significant issue in the case of impact. When interlaminar properties of only 0//0 interface is used in all interfaces of the cohesive zone analyses, results generally do not match with experiment ones. In order to improve these analyses, a meaningful array of interface properties for experimental fracture toughness values must be known. For example, a delamination in a 0//0 interface can propagate in any direction. Moreover, delaminations are not in 0//0 interface. In general; it can be in any interface including 0//90, 0//45 etc. There is program created for determining the interlaminar properties for delamination of different interfaces by utilizing double cantilever beam (DCB), end-notched flexure (ENF) and curved beam strength (CBS) experiments. In this part of the program, Mode I fracture toughness values of 0//0, 45//45 interfaces are considered in the experimental program. Mode I experiment is conducted according to ASTM D5528 (Ref. 2). The program will continue with Mode I and Mode II fracture toughness values, and interlaminar strength values of 0//0, 25//25, 45//45, 65//65, 90//90, 25//-25, 45//-45, 65//-65 interfaces. These results provide a practical material tool covering various range of interfaces of fracture toughness for certain CFRP and GFRP unidirectional laminates. It will hopefully decrease the problems in computational studies which generally use only 0//0 interface properties for all interfaces.

Subject Keywords

Delamination, Crack bridging, Composite laminates

URI

https://hdl.handle.net/11511/74406
https://www.scopus.com/record/display.uri?eid=2-s2.0-85084016932&origin=resultslist&sort=plf-f&src=s&st1=&st2=&sid=4f68e9f0eb9c69f71ff48cdbc82719ef&sot=b&sdt=b&sl=84&s=TITLE-ABS-KEY+%28Effect+of+lay-up+orientation+on+fracture+toughness+of+CFRP+laminates%29&relpos=0&citeCnt=0&searchTerm=

Conference Name

7th Asian/Australian Rotorcraft Forum (30 October - 1 November 2018)

Collections

Department of Aerospace Engineering, Conference / Seminar

Suggestions

OpenMETU
Core

Effect of thickness and pre-crack length on delamination of unidirectional l-shaped laminated composites Gozluklu, Burak; Yavas, Denizhan; Çöker, Demirkan (null; 2012-12-01) It is widely assumed that delamination initiates at the curved region of the Lshaped laminate leading to loss of loading carrying capacity. However, as shown in this paper, under certain conditions a second failure mode in thick L-shaped laminates is observed in which a secondary crack initiates at the arm region. Delamination in L-shaped laminates is modeled using dynamic (explicit) finite element analysis in conjunction with cohesive zone methods. The 2-D model consists of 24 plies of unidirectional CFRP ...
Role of Laminate Thickness on Sequential Dynamic Delamination of Curved [90/0] CFRP Composite Laminates Uyar, Imren; Tasdemir, B.; Yavas, D.; Çöker, Demirkan (2016-06-09) In aerospace industry, high demand for the lightweight structures are fostering the use of carbon fiber reinforced polymer composites in a wide variety of shapes, as primary load carrying elements. However, once a composite laminate takes a highly curved shape, such as an L-shape, interlaminar stresses augmented in the curved region cause highly dynamic delamination nucleation and propagation. This paper provides experimental observations of dynamic delamination failure in cross-plied L-shaped composite lam...
Effect of resin and fiber on the abrasion, impact and pressure resistance of cylindrical composite structures Kaya, Derya; Yılmazer, Ülkü; Department of Chemical Engineering (2011) The aim of this study was to investigate the effects of resin and fiber on the abrasion, impact and internal pressure resistances of fiber reinforced plastic composite pipes produced by continuous filament winding method. For this study, pipe samples were produced with different combinations of resin type, fiber type, fiber amount and fiber length. All the samples were tested in accordance with the related ISO (International Organization for Standardization), DIN (German Standardization Institution) and BSI...
Effect of hydrogen on fatigue behavior of a cadmium coated high strength steel Güleken, Ümran Başak.; Gürbüz, Rıza; Department of Metallurgical and Materials Engineering (2019) C Despite the associated health and safety concerns of Cadmium, this material remains the most commonly used fastener plating material in aerospace applications. The plating operation is done by a well understood and common electrodeposition process. If a cadmium plated part has high strength (1000 MPa and above) then in order to prevent hydrogen embrittlement it must be baked at 191°C for 23 hours, within 2 hours after plating. Yet it has been seen that parts fail due to hydrogen embrittlement during servi...
Effect of microstructure on fracture toughness of coarse grain heat aff ected zone in as welded X70M steel Cagırıcı, Mehmet; Tosun, Uygar; Gür, Cemil Hakan (null; 2016-10-01) Fracture toughness behavior of coarse-grain heat affected zone (CGHAZ) of the welds in API5LX70M pipes has been investigated by Charpy impact and crack tip opening displacement (CTOD) tests at -10°C. The present work also includes comprehensive pre- and post-test metallography and analyses. A correlation between local brittle and soft spots in intercritically reheated coarse-grain heat affected zone (ICCGHAZ) and toughness of the as-welded material has been observed. The degree of dilution and the microstru...

Citation Formats

B. O. Yavuz, D. Çöker, and K. L. Parnas, “Effect of lay-up orientation on fracture toughness of CFRP laminates,” Jeju Island, South Korea, 2018, vol. 1-2, p. 1069, Accessed: 00, 2021. [Online]. Available: https://hdl.handle.net/11511/74406.