EXPERIMENTAL AND COMPUTATIONAL INVESTIGATION OF DEBONDING AT THE INTERFACE OF TWO L-SHAPED POLYCARBONATE PLATES

Date

2012-11-15

Author

Yavas, Denizhan
Uyar, Imren
Gozluklu, Burak
Çöker, Demirkan

Metadata

Show full item record

This work is licensed under a Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License.

Item Usage Stats

37
views

0
downloads

L-shaped composite structures are increasingly replacing metal ribs and box structures especially in recent civil aerospace structures and wind turbine blades. De lamination of these L-shaped composite laminates occur by interlaminar opening stresses at the curved region under perpendicular loading to one arm. In this study, delamination at the curved region is studied experimentally and computationally by using a simplified model material consisting of two L-shaped polycarbonate plates bonded together. The effect of precrack size at the curved region on the initiation and propagation of delamination under loading perpendicular to one of the arms is studied. Experimental observations are carried out using photoelasticity to visualize the isochromatic stress patterns in the model: Finite element analysis (ABAQUS) is carried out using static (implicit) analysis during elastic loading followed by dynamic (explicit) analysis during crack growth in conjunction with a bilinear cohesive zone model. For precracks smaller than 40mm, a sudden drop in loaddisplacement plot is observed corresponding to dynamic crack growth at 80 m/s crack tip speed from the corner to the arms. Afterwards, a generally monotonic increase in load-displacement behavior is observed albeit with a lower stiffness corresponding to continued stable crack growth. For larger pre-cracks, loaddisplacement increases monotonically even after crack initiates with stable stick-slip type crack growth. These two regimes of crack growth are consistent with the observations of Wimmer et al (2009) on cross-ply composite L-beams.

Subject Keywords

Delamination, Composites, Growth

URI

https://hdl.handle.net/11511/53800

Collections

Department of Aerospace Engineering, Conference / Seminar

Suggestions

OpenMETU
Core

Experimental Observations of Dynamic Delamination in Curved [0] and [0/90] Composite Laminates Uyar, I.; Arca, M.A.; Gozluklu, B.; Çöker, Demirkan (2015-01-01) Curved composite parts are increasingly replacing metal ribs and box structures in recent civil aerospace structures and wind turbine blades. Delamination of L-shaped composite laminates occurs by interlaminar opening stresses in addition to the interlaminar shear stresses at the curved region. An experimental setup is designed to investigate dynamic delamination in L-shaped composite brackets under quasi static shear loading. The materials are unidirectional [0]17and cross-ply [0/90]17 epoxy/graphite compo...
Experimental Observations of Dynamic Delamination in Curved [0] and [0/90] Composite Laminates Imren, Uyar; Miray, Arca; Burak, Gozluklu; Çöker, Demirkan (null, Springer, 2015-01-01) Curved composite parts are increasingly replacing metal ribs and box structures in recent civil aerospace structures and wind turbine blades. Delamination of L-shaped composite laminates occurs by interlaminar opening stresses in addition to the interlaminar shear stresses at the curved region. An experimental setup is designed to investigate dynamic delamination in L-shaped composite brackets under quasi static shear loading. The materials are unidirectional [0]17and cross-ply [0/90]17 epoxy/graphite compo...
Experimental investigation of failure mechanism in cross-ply and fabric curved composite laminates Çevik, Ahmet; Çöker, Demirkan; Department of Aerospace Engineering (2021-8) Laminated curved-shape composite parts which are used in the spar and ribs in aircraft and wind turbine blades are subjected to high interlaminar tensile and shear stresses. These stresses cause delamination and subsequent reduction in load-carrying capacity. In this study, failure mechanism of cross-ply and fabric curved composite laminates under pure transverse loading are examined experimentally using an in-house designed test fixture. Stress field over the curved beam is obtained with finite element ana...
Experimental and numerical investigation of damage induced by transverse impact in composite beams and plates Bozkurt, Miraç Onur; Çöker, Demirkan; Department of Aerospace Engineering (2019) Engineering parts made of composite material are susceptible to impacts such as tool drop, hail strike, and bird strike. Since impact induced damage leads to considerable losses in the residual strength, damage mechanisms should be understood well and modelled accurately. For this purpose, damage process in composite laminates under low-velocity impact is investigated experimentally and numerically for two geometries: (i) beams and (ii) plates. In the first part of the thesis, experimental and numerical stu...
Delamination-Debond Behaviour of Composite T-Joints in Wind Turbine Blades Gulasik, H.; Çöker, Demirkan (2014-06-20) Wind turbine industry utilizes composite materials in turbine blade structural designs because of their high strength/stiffness to weight ratio. T-joint is one of the design configurations of composite wind turbine blades. T-joints consist of a skin panel and a stiffener co-bonded or co-cured together with a filler material between them. T-joints are prone to delaminations between skin/stiffener plies and debonds between skin-stiffener-filler interfaces. In this study, delamination/debond behavior of a co-b...

Citation Formats

D. Yavas, I. Uyar, B. Gozluklu, and D. Çöker, “EXPERIMENTAL AND COMPUTATIONAL INVESTIGATION OF DEBONDING AT THE INTERFACE OF TWO L-SHAPED POLYCARBONATE PLATES,” 2012, Accessed: 00, 2020. [Online]. Available: https://hdl.handle.net/11511/53800.