extensive capabilities of NASFLA, the central life assessment code of NASGRO®,
distinguish it from many other fracture
mechanics codes. The NASFLA module can be used to perform many different types
of fracture mechanics assessments, such as:
Computing stress intensity factors
for a given crack geometry and loading and display them in tabular or
graphical form. More than 78 different geometries are available.
Calculating fatigue crack growth
rate using the geometry, initial crack size, and loading spectrum, and
ultimately determining the number of load blocks or cycles that cause the crack
to become unstable. The NASGRO® crack growth equation,
the walker equation and tabular data are used for this.
Computing the critical initial crack
size that will grow to failure when a specified load history is applied.
Computing the critical final crack
size for which the applied stress intensity factor under a given load is equal
to the material fracture toughness.
Performing a sustained crack growth
analysis to calculate crack growth rate and determine the time that a constant
load can be sustained before a glass or glass-like material fails.
NASFLA contains a variety of
options for defining fatigue load histories.
Structural Engineering Department
Southwest Research Institute®
(SwRI®) is an independent, nonprofit, applied engineering and physical
sciences research and development organization with
technical divisions using
multidisciplinary approaches to problem solving. The Institute
occupies 1,200 acres and provides
nearly two million square feet of laboratories, test facilities, workshops, and offices for more than 2,800 employees who perform contract work for industry and government clients.