Effect of Fiber/Matrix Interface on Strain Energy Release Rate of Delamination Crack Tip in FRP

2003 ◽  
Vol 2003.16 (0) ◽  
pp. 799-800
Author(s):  
Yoshikazu Nakai ◽  
Hiroshi Tanaka ◽  
Nobuyuki Hina
2018 ◽  
Vol 53 (4) ◽  
pp. 425-443 ◽  
Author(s):  
Weiling Zheng ◽  
Christos Kassapoglou

An energy method based on beam theory is proposed to determine the strain energy release rate of an existing crack in composite laminates. The developed analytical method was implemented in isotropic materials, and the obtained strain energy release rate of a crack was validated by reference results and finite element solutions. The general behavior of crack growth on the left or right crack tip was evaluated, and basic trends leading to crack propagation to one side of the crack were established. A correction factor was introduced to improve the accuracy of the strain energy release rate for small cracks. The singularity at the crack tip caused by dissimilar materials was investigated and was found that the inclusion of the singularity effect could increase the accuracy for small cracks. The calculated strain energy release rate of a crack in a composite beam has been verified by comparing with a finite element model.


2016 ◽  
Vol 08 (06) ◽  
pp. 1650077 ◽  
Author(s):  
M. Chabchoub ◽  
B. Vieille ◽  
M. Beyaoui ◽  
M. Taktak ◽  
M. Haddar ◽  
...  

The strain energy release rate [Formula: see text] is of prime importance in composite materials fracture mechanics. In order to experimentally and numerically evaluate this parameter in the case of quasi-isotropic and angle-ply (AP) woven-ply thermoplastic (TP) laminates, single edge notched (SEN) specimens have been subjected to monotonic tensile loading at [Formula: see text] when the toughness and the viscous behavior of the (TP) matrix are exacerbated. From the simulation standpoint, a particular attention was paid to the type of meshing as well as its refinement in the vicinity of the crack tip where the triaxiality rate leads to significant stress concentrations. For this purpose, a linear spectral viscoelastic and a generalized Norton-type viscoplastic models have been used. A comparison between two types of meshing (radiant and concentric) has been conducted. Both types of meshing allow us to define crowns in order to represent the surface of the integration ring around the crack tip. These crowns are necessary to evaluate the strain energy release rate [Formula: see text] in opening mode using [Formula: see text]-integral computation. Both overstress and overstrain profiles near the crack tip were investigated and validated using theoretical stress fields derived from the linear elastic fracture mechanics (LEFM) framework and overstrain fields obtained from digital image correlation (DIC) to verify the model’s ability to provide accurate mechanical fields at singularity zones.


1964 ◽  
Vol 86 (4) ◽  
pp. 693-697 ◽  
Author(s):  
R. G. Forman ◽  
A. S. Kobayashi

This paper presents theoretical studies on the axial rigidities in strips with circular and elliptical perforations and subjected to uniaxial tension. Greenspan’s original derivations on these axial rigidities [2] were improved by using the elasticity solutions by Howland [6] and Ishida [7] for infinite strips with circular and elliptical perforations, respectively. Finally, the correction factors for centrally notched strips subjected to uniaxial tension were rederived from the above results following the energy approach by Irwin and Kies [3].


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