The 3-day class will familiarize students with the design and operation of the AFGROW crack growth life analysis program. This will include a review of Linear Elastic Fracture Mechanics (LEFM) concepts, example problems, and new capabilities/features in the current release (Version 5.3), including: the ability to use different crack growth rate data for different crack growth directions and as a function of the applied loading spectrum, and our new spectrum management tool.
The class will also provide an introduction to the use of advanced features unique to AFGROW (COM automation, Advanced Multiple Crack Solutions, and Plug-In K-Solutions).
More Information
Section 3.2.3.1. Durability Analysis
A probabilistic approach to characterizing structural
durability has been extensively explored by Manning and Yang [1987, 1989]. For the durability analysis, the growth of a
distribution of equivalent initial flaw sizes for a population of structural
elements is calculated as a function of flight hours in the expected usage
environment. Durability is then
characterized in terms of either the expected number of cracks that will exceed
a fixed size as a function of flight hours or in
terms of the distribution of flights to reach a crack of given size. These concepts are illustrated in Figure 3.2.10, from Manning & Yang [1989], in
which:
– EIFSD
represents the equivalent initial flaw size distribution of initial quality;
– p(i,t) represents the distribution of number
of cracks of a size larger than x;
– FT(x) (t) represents the
distribution of service time to reach a crack of size x.
The EIFSD must be projected
forward based on a crack growth methodology that is compatible with that used to produce the EIFSD. Manning and Yang
recommend a combined deterministic crack growth analysis (DCGA) and stochastic
crack growth analysis (SCGA) for projecting the EIFSD.

Figure 3.2.10. Schematic Using the Equivalent Initial Crack
Size Distribution (EIFSD) for Durability Analysis