Delamination growth behavior of a woven E-glass/bismaleimide composite in seawater environment

2016 ◽  
Vol 106 ◽  
pp. 332-343 ◽  
Author(s):  
Yian Zhao ◽  
Wei Liu ◽  
Leong Keey Seah ◽  
Gin Boay Chai
Keyword(s):  
Growth Behavior ◽  
Delamination Growth ◽  
Seawater Environment

Influence of Ply Sequence and Thermoelastic Stress Field on Asymmetric Delamination Growth Behavior Emanating From Elliptical Holes in Laminated FRP Composites

2007 ◽  
Vol 130 (1) ◽  
Author(s):  
Brajabandhu Pradhan ◽  
Poosa Ramesh Babu
Keyword(s):  
Stress Field ◽  
Energy Release ◽  
Strain Energy ◽  
Thermoelastic Stress ◽  
Strain Energy Release ◽  
Growth Behavior ◽  
Delamination Growth ◽  
Elliptical Holes ◽  
Delamination Front ◽  
Thermoelastic Stress Field

The present study encompasses the influence of ply sequence and thermoelastic stress field on asymmetric delamination growth behavior emanating from elliptical holes in laminated fiber reinforced polymeric composites. Results, emphasizing the effect of thermal residual stresses on delamination growth behavior of the composite laminates subjected to two different loading conditions, i.e., in-plane tensile and compressive loadings, are presented. Two sets of full three-dimensional finite element analyses have been performed to calculate the displacements and interlaminar stresses along the delaminated interfaces responsible for the delamination onset and propagation. Modified crack closure integral methods based on the concepts of linear elastic fracture mechanics have been followed to evaluate the individual modes of strain energy release rates along the delamination front. In each case, the delamination is embedded at a different depth along the thickness direction of the laminates. It is observed that the fiber orientation of the plies bounding the delamination front significantly influences the distribution of the local strain energy release rate. Also, the residual thermal stresses have a detrimental effect on the laminates subjected to compressive loading and more so in the case of laminates with delaminations existing closer to the top and bottom surfaces of the laminate.

scholarly journals A novel interpretation of fatigue delamination growth behavior in CFRP multidirectional laminates

2016 ◽  
Vol 133 ◽  
pp. 79-88 ◽  
Author(s):  
Libin Zhao ◽  
Yu Gong ◽  
Jianyu Zhang ◽  
Yana Wang ◽  
Zizi Lu ◽  
...  
Keyword(s):  
Growth Behavior ◽  
Delamination Growth

Delamination Growth Behavior of a Fabric Reinforced Laminated Composite Under Mode I Fatigue

1999 ◽  
Vol 121 (3) ◽  
pp. 381-385 ◽  
Author(s):  
D. R. Atodaria ◽  
S. K. Putatunda ◽  
P. K. Mallick
Keyword(s):  
Growth Rate ◽  
Energy Release Rate ◽  
Energy Release ◽  
Release Rate ◽  
Strain Energy ◽  
Strain Energy Release Rate ◽  
Laminated Composite ◽  
Strain Energy Release ◽  
Growth Behavior ◽  
Delamination Growth

The purpose of this study is to investigate the delamination growth behavior of a glass fabric reinforced laminated composite under Mode I fatigue loading and to examine the applicability of a new fatigue crack growth rate model to this material. In this study, double contilever beam specimens were subjected to tension-tension cyclic loads with three different load ratios and the delamination growth rate was measured using the compliance method. The delamination growth rate was related to the strain energy release rate during fatigue cycling by a power law equation that takes into account not only the effect of the strain energy release rate range, but also the effect of delamination growth at various stages of loading using a weight average strain energy release rate. It was observed that this new model can represent the delamination growth rate of the fabric reinforced laminated composite at three different load ratios in a single unifying curve.

Experimental Investigation of Compressive Overloads on Delamination Growth Behavior in Fatigued Composites

1999 ◽  
Author(s):  
Assimina A. Pelegri ◽  
Charles Valentine
Keyword(s):  
Fatigue Testing ◽  
Compressive Loading ◽  
Fatigue Tests ◽  
Growth Behavior ◽  
Experimental Program ◽  
Laminate Composites ◽  
Variable Amplitude ◽  
Delamination Growth ◽  
Aerospace Applications ◽  
Compressive Loads

Abstract The behavior of laminated graphite/epoxy composites under variable amplitude compressive loading is studied. Laminate composites in aerospace applications undergo both compressive and tensile fatigue stresses as well as spectrum loading. These materials are particularly susceptible to compressive loads and overloads, which cause the growth of any small pre-existing delaminations. Such delamination growth, and the resulting sublaminate buckling, are major causes of fatigue failure. This experimental program investigates the effects of overloads on laminate composite specimens in which small delaminations are introduced during fabrication. The delamination growth is monitored in real time during fatigue tests. Different variable amplitude load spectra are applied, and the delamination position through the depth of the specimens is varied. Up to now, research has focused on constant amplitude fatigue testing or simple two block testing. Some variable amplitude studies have been done but attention has mostly been given to the reduction in residual strength or stiffness of the specimen. Much of the prior work is done in tension instead of compression. This investigation will provide data specifically on the growth behavior of pre-existing delaminations in composites under compressive overloads.

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