Effect of Drilling-Induced Delamination on Buckling Behavior of Open Hole Composite Laminate Specimens Under Compressive Loading

Boron Nitride nanotubes (BNNTs) together with carbon nanotubes (CNTs) have attracted the wide attention of the scientific community and have been considered as promising materials due to their unique structural and physical properties. In this paper, the behavior of BNNTs of different diameters under compressive loading has been studied through molecular dynamic (MD) simulations. We have used a Lennard-Jones pair potential to characterize the interactions between non-bonded atoms and harmonic potentials for bond stretching and bond angle vibrations. Results of the MD simulations determine the critical buckling loads of the BNNTs of various diameters under uniaxial compression, and indicate that for the simulated BNNTs of length L = 6 nm, the critical buckling loads increase by increasing the nanotube diameters.

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Flexural Testing of Composite Laminates for Drilling Trial Assessment

Advanced Composites Letters ◽

10.1177/096369350000900403 ◽

2000 ◽

Vol 9 (4) ◽

pp. 096369350000900

Author(s):

I.R. Farrow ◽

J. Lee ◽

C.D. Kong

Keyword(s):

Composite Laminates ◽

Composite Laminate ◽

Static Tension ◽

Hole Quality ◽

Flexural Testing ◽

Open Hole ◽

Drilling Parameter ◽

Flexural Tests ◽

Notched Strength ◽

Composite Samples

This work presents a study of flexural testing as a convenient method for ranking drilling trials of composite materials. The work includes an experimental study of drilling parameter effects on composite laminate hole quality as measured by static tension, compression and flexural open hole tests. Flexural testing and results processed in terms of the outermost 0° layer provides a consistent ranking of holes drilled with different process parameters despite only subtle changes in static notched strength for the thick composite samples tested. Specific observations from flexural tests are consistent with current drilling practices in terms of best process parameter settings and the method shows sufficient sensitivity to distinguish between the effects of drill-entry and drill-exit damage and subtle changes in lay-up.

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Approximate Biaxial Stress Solution for Orthotropic Open-Hole Composite Laminates

Advanced Composites Letters ◽

10.1177/096369359600500402 ◽

1996 ◽

Vol 5 (4) ◽

pp. 096369359600500

Author(s):

C. Filiou ◽

C. Soutis

Keyword(s):

Approximate Solution ◽

Stress Distribution ◽

Circular Hole ◽

Composite Laminates ◽

Composite Laminate ◽

Biaxial Loading ◽

Biaxial Stress ◽

Orthotropic Composite ◽

Open Hole ◽

Simple Approximate Solution

A simple approximate solution has been derived for the stress distribution near a circular hole applicable to any orthotropic composite laminate subjected to biaxial loading. The degree of accuracy of this solution was found to be overall acceptable, but strongly dependent upon the laminate lay-up and biaxiality ratio.

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