Continuum modeling of interface failure
Loading...
Authors
Griffiths, Robert P.
Subjects
Advisors
Kwon, Young W.
Date of Issue
2007-12
Date
Publisher
Monterey, California. Naval Postgraduate School
Language
Abstract
Two-dimensional continuum modeling and simulations were conducted to predict how the size, quantity, and stiffness of reinforcing particles such as carbon nanotubes (CNTs) affect failure mechanisms at the interface of composite structures. First, the strength model used the finite element method (FEM) on a slender composite beam with step-joint containing reinforcing particles to predict its critical stress-strain behavior at the joint interface under compressive axial load. Next, the fracture mechanics model used the virtual crack extension method on the same composite beam containing an internal crack to predict how the energy release rate was affected by reinforcing particles at the interface under the same compressive axial load. Comparing the two results to experimental data showed that the fracture mechanics model predicted the interface failure behavior better than the strength model. Finally, the fracture mechanics model was used for a composite plate containing an edge crack to study how the energy release rate was affected by several parameters of reinforcing particles near the crack tip under transverse shear load. In each case, homogeneous models served as baselines for comparative analyses. Outcome of this work not only represents reliable and efficient modeling of composite interfaces in order to improve failure strength through the addition of nanoscale reinforcing particles such as CNTs but also serves to focus future research in structural application of CNTs, especially within testing and evaluation of CNTs in composite scarf-joint interfaces.
Type
Thesis
Description
Series/Report No
Department
Organization
Naval Postgraduate School (U.S.)
Identifiers
NPS Report Number
Sponsors
Funder
Format
xii, 41 p. ;
Citation
Distribution Statement
Approved for public release; distribution is unlimited.