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 9.3.3.0. Crack Growth Analysis
The simplest manner for differentiating a curve is by using the
secant method, i.e.

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(9.3.5)
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where (a1, F1)
and (a2, F2) represent two different
points on the crack growth life, crack length (a) versus flights (F)
curve. The derivative is considered to
be the slope of the curve at the mean crack length of the two points, ie.

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(9.3.6)
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The mean crack length provides the
ability to calculate the stress-intensity factor coefficient (K/s)
for the geometry associated with the crack growth life curve. To describe the crack growth rate as a
function of stress-intensity factor, it is necessary to have either a formula
or graph that relates stress-intensity factor to crack length for a known
external loading condition. For
example, if the stress-intensity factor is related to gross stress conditions (sgross) by the formula

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(9.3.7)
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Then
the stress-intensity factor coefficient is

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(9.3.8)
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and Equation 9.3.8 is evaluated for a = amean
(Equation 9.3.6). Note that b is typically a function of crack length.