scholarly journals The Effects of Starter Film Thickness, Residual Stresses and Layup on GIc of a 0°/0° Interface

1996 ◽  
Vol 5 (6) ◽  
pp. 096369359600500 ◽  
Author(s):  
P. Robinson ◽  
S Foster ◽  
JM Hodgkinson
Keyword(s):  
Fracture Toughness ◽  
Residual Stresses ◽  
Film Thickness ◽  
Mode I ◽  
Epoxy System ◽  
Natural Interface ◽  
Delamination Fracture ◽  
Mode I Delamination

This paper reports on an investigation of the mode I delamination fracture toughness of 0°/0° interfaces in a carbon-epoxy system (T800-924). It has been found that thicker starter films give a lower GIc. The toughness of a natural interface (ie unaffected by the presence of a starter film) has been found to be closest to the toughness measured using the thinnest starter films. Tests on 0°/0° interfaces in multidirectional laminates have shown that residual stresses have a significant effect on GIc. Finally, it has been shown that bend-twist coupling in the arms of the Mode I specimen can lead to considerable changes in the apparent toughness.

A Study on the Fracture Characteristics of Plasma-Treated Graphite/Epoxy Laminated Composites

2006 ◽  
Vol 321-323 ◽  
pp. 869-872 ◽  
Author(s):  
M.H. Kim ◽  
Kyong Yop Rhee ◽  
Young Nam Paik ◽  
S.H. Ryu
Keyword(s):  
Contact Angle ◽  
Double Cantilever Beam ◽  
Treatment Time ◽  
Laminated Composites ◽  
Mode I ◽  
Fracture Characteristics ◽  
Delamination Fracture ◽  
Delamination Resistance ◽  
Fracture Tests ◽  
Mode I Delamination

For a present study, the surfaces of graphite/epoxy prepregs were modified using plasma treatment to improve the delamination resistance behavior of graphite/epoxy laminated composites. The optimal treatment time was determined by measuring the change of contact angle with treatment time. Unidirectional DCB (double cantilever beam) specimens were used in the mode I delamination fracture tests. The delamination resistance curve of regular (untreated) specimen was compared with that of plasma-treated specimen in order to determine the effect of prepreg treatment on the resistance behavior. It was found that contact angle was changed from ~64° to ~47° depending on the treatment time. The contact angle was a minimum for a 30 min treatment time. It was also found that delamination resistance behavior of graphite/epoxy composites was improved about 20%.

Influence of through-thickness reinforcement aspect ratio on mode I delamination fracture resistance

2015 ◽  
Vol 125 ◽  
pp. 13-22 ◽  
Author(s):  
Sergii G. Kravchenko ◽  
Oleksandr G. Kravchenko ◽  
Leif A. Carlsson ◽  
R. Byron Pipes
Keyword(s):  
Aspect Ratio ◽  
Fracture Resistance ◽  
Mode I ◽  
Delamination Fracture ◽  
Mode I Delamination

The Influence of Thermoplastic Film Interleaving on the Interlaminar Shear Strength and Mode I Fracture of Laminated Composites

1996 ◽  
Vol 118 (3) ◽  
pp. 302-309 ◽  
Author(s):  
L. Li ◽  
P. Lee-Sullivan ◽  
K. M. Liew
Keyword(s):  
Fracture Toughness ◽  
Shear Strength ◽  
Film Thickness ◽  
Beam Theory ◽  
Interlaminar Shear Strength ◽  
Mode I ◽  
Mode I Fracture ◽  
Mode I Fracture Toughness ◽  
Fibre Bridging ◽  
Interlaminar Shear

Results are presented on the interlaminar shear strength (ILSS) and Mode I fracture toughness (GIC) of glass/epoxy laminates interleaved with thermoplastic polyester films using four-point bending and double cantilever beam tests, respectively. The ILSS equation from classical beam theory was modified to account for the increased film thickness. It was found that the ultimate failure load and ILSS could be doubled if a thermoplastic film of high ductility but low glass transition temperature is used. Good film/composite ply adhesion is necessary. Mode I fracture toughness is influenced by film thickness and interleaving with a 0.2 mm thick film increased the GIC by 40 percent. Interleaving with a thinner film (0.1 mm), however, resulted in adhesive failure and reduced fibre bridging.

R-Curve Modelling of Mode I Delamination in Multidirectional Carbon/Epoxy Composite Laminates

2014 ◽  
Vol 606 ◽  
pp. 159-163 ◽  
Author(s):  
K.J. Wong ◽  
Xiao Jing Gong ◽  
Shahram Aivazzadeh ◽  
Mohd Nasir Tamin
Keyword(s):  
Fracture Toughness ◽  
Finite Element ◽  
Composite Laminates ◽  
Composite Laminate ◽  
Epoxy Composite ◽  
Mode I ◽  
Fibre Bridging ◽  
Element Simulation ◽  
Force Displacement ◽  
Mode I Delamination

In the present work, the mode I delamination behaviour of a quasi-isotropic quasi-homogeneous carbon/epoxy composite laminate with adjacent plies of 0o//45o is studied numerically. To describe the R-curve behaviour observed during crack propagation, a linear-exponential traction-separation law is proposed, where the fracture toughness and the increment in the fracture energy could be considered separately in the model. This model is then implemented in the finite element simulation of the delamination process in the composite laminate. Numerical results indicate that with the incorporation of the fibre bridging effect leads to a well-predicted force-displacement response of the composite laminates.

Mode I type delamination fracture toughness of YBCO coated conductor with additional Cu layer

2011 ◽  
Vol 471 (21-22) ◽  
pp. 1071-1074 ◽  
Author(s):  
T. Miyazato ◽  
M. Hojo ◽  
M. Sugano ◽  
T. Adachi ◽  
Y. Inoue ◽  
...  
Keyword(s):  
Fracture Toughness ◽  
Mode I ◽  
Coated Conductor ◽  
Ybco Coated Conductor ◽  
Delamination Fracture
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