Computational Methods for Debonding in Composites

Chapter 3
Practical Challenges in Formulating Virtual
Tests for Structural Composites
Brian N. Cox, S. Mark Spearing, and Daniel R. Mumm
Abstract Taking advantage of major recent advances in computational methods and
the conceptual representation of failure mechanisms, the modeling community is
building increasingly realistic models of damage evolution in structural composites.
The goal of virtual tests appears to be reachable, in which most (but not all) real
experimental tests can be replaced by high fidelity computer simulations. The payoff
in reduced cycle time and costs for designing and certifying composite structures is
very attractive; and the possibility also arises of considering material configurations
that are too complex to certify by purely empirical methods. However, major challenges
remain, the foremost being the formal linking of the many disciplines that
must be involved in creating a functioning virtual test. Far more than being merely
a computational simulation, a virtual test must be a system of hierarchical models,
engineering tests, and specialized laboratory experiments, organized to address the
assurance of fidelity by applications of information science, model-based statistical
analysis, and decision theory. The virtual test must be structured so that it can
function usefully at current levels of knowledge, while continually evolving as new
theories and experimental methods enable more refined depictions of damage.
To achieve the first generation of a virtual test system, we must pay special attention
to unresolved questions relating to the linking of theory and experiment: how
can we assure that damage models address all important mechanisms, how can we
calibrate the material properties embedded in the models, and what constitutes sufficient
validation of model predictions? The virtual test definition must include real
tests that are designed in such a way as to be rich in the information needed to
B.N. Cox
Teledyne Scientific Co., LLC, 1049 Camino Dos Rios, Thousand Oaks, CA 91360, United States
of America, e-mail: bcox@teledyne.com
S.M. Spearing
School of Engineering Sciences, University of Southampton, Southampton, SO17 1BJ, United
Kingdom, e-mail: spearing@soton.ac.uk
D.R. Mumm
University of California, Irvine, CA, United States of America, e-mail: mumm@uci.edu
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