FAARFIELD 1.204 -
Computer Program for Airport Pavement Thickness Design
FAARFIELD
1.204 is a 32-bit
version and requires Windows XP or later.
Uninstalling previous versions
of FAARFIELD is advised.
Setup requires the following files:
Setup.Exe
FAARFIELDSetup.msi
Copy all of the files into a
temporary directory on a hard disk. Then run setup.exe. Setup can also be run
from the distribution disk.
The Alternate SG check box allows a flexible
pavement design (or Life) to be run based on the vertical strain at the top of
the layer below the arrow on the left side of the pavement structure. The
procedure is: 1) get into the Structure window, 2) check the Alternate SG box at
the bottom left of the structure, 3) press the Modify button, 4) click to the
left of the picture of the structure (in the margin) to move the arrow so that
it sits to the left of the layer above the layer where the vertical strain
criterion will be applied, 5) return to design mode, 6) if a design is run then
the layer pointed to by the arrow will change thickness to satisfy the strain
criterion in the layer below, 7) if Life is run then the life for the strain
criterion in the layer below will be calculated.
See the help file under
Running the Program - Options for information on Batch, No HMA CDF, and No Out
Files.
FAARFIELD is released for public evaluation and review, with the
understanding that FAARFIELD 1.204 is not a currently approved FAA
design standard or specification. The FAA does not officially support the
program as a standard nor sanction any use of the results. FAARFIELD may be
updated from time to time, so it is advisable for users to check the web page
(http://www.airporttech.tc.faa.gov/download/) regularly for updates. FAARFIELD
1.204 includes a 3-dimensional finite element model (FEM) for rigid
pavement response calculations. The use of 3-dimensional FEM allows the
direct computation of edge stresses under aircraft gear loads and eliminates the
need to estimate the edge stress based on the interior load as was done in
LEDFAA. The flexible design procedure remains unchanged from LEDFAA
1.3.
FAARFIELD 1.204 includes the Airbus A380-800 and A380-800F
aircraft in the airplane library. The treatment of these airplane types in
FAARFIELD 1.204 is identical to LEDFAA 1.3, except that for rigid pavement
design, the computation of edge stresses for both wing and body gears is
performed by 3-dimensional finite element analysis. For additional information
on A380 treatment in the design procedure, please refer to LEDFAA 1.3
documentation.
Please note that the default setting for data output files
(*.out) is for them not to be written. Double click on the gray area of the
Structure Window and uncheck "No Out Files" for the
data files to be written to the working directory, or uncheck “No Out Files”
from the Options window.
A number of FAA workshops are planned to
accompany the review process. The dates and locations of the workshops will be
announced.
FAARFIELD v. 1.203 July 31, 2008:
FAARFIELD v. 1.203 replaces all previous versions of FAARFIELD. In particular, FAARFIELD v. 1.203 replaces FAARFIELD v. 1.100 that accompanied Draft AC 150/5320-6E.
Major changes implemented in FAARFIELD version 1.203 are as follows:
1. The pavement thickness is now computed for constant tire contact area. Changing the airplane gross weight causes the tire pressure to be adjusted to maintain the contact area. In previous versions the tire pressure was held constant.
2. Additional XML (Extensible Markup Language) support has been added. Job files are now in XML format. In addition, the external airplane library file has been converted to XML format. FAARFIELD automatically detects job files or external airplane libray files in the previous format and converts them to the new XML format, moving the original files to a subdirectory old_job_files in the working directory. All subsequent changes will be made only to the XML files.
3. A function to display CDF files graphically has been added.
4. An enhanced Airplane Data window now displays the gear coordinates using a mouse-over function. The Airplane Data window now displays x and y scales.
5. Support for PCC over rubblized base has been added.
6. Hitting Alt-O in the Pavement Structure, Airplane, or Airplane Data windows brings up the Options window.
7. The word “Aircraft” has been replaced with “Airplane” or “Airplanes” as appropriate.
8. Errors that prevented the writing, saving and editing of Notes files in previous versions have been fixed.
9. The program now opens in the same system of units that was used in the previous session. Previously, the program always opened in the default (English) system of units.
10. The external airplane file was “cleaned” of unnecessary airplanes, and now contains the same airplane data as the COMFAA external airplane library.
11. For files generated by the Save XML command, the file extension was changed to *.DES.xml (rather than just *.xml). This allows the design information files to be distinguished from the *.JOB.xml files and any other files in XML format.
12. The program no longer generates the pltdata.dat file. This function has been replaced by a separate utility program called NIKEPLOT.
13. A bug in previous versions sometimes caused dialog boxes to “hide” behind the Structure window, requiring the user to terminate the session. This bug has been fixed.
14. A new internal pass-to-coverage ratio (P/C) computational routine has been fully implemented.
15. The design information summary now reports P/C and CDF information for both Subgrade CDF and HMA CDF (if the latter is performed) in separate tables.
FAARFIELD v. 1.204 November 24, 2008:
FAARFIELD v. 1.204 replaces all previous versions of FAARFIELD.
Changes implemented in FAARFIELD version 1.204 are as follows:
1.
Corrected a problem with date formatting that
occurred when some Windows regional and language settings other than English
(
2. Corrected a bug that caused a run time error when reading and converting certain LEDFAA job files.
3. In previous versions, not all the evaluation points were included in strain evaluation for A380 and B747-400 airplanes for flexible pavements. This has been corrected.
4. In previous versions, the rigid pavement design procedure terminated after 5 iterations regardless of whether the program changed the subbase layer thickness in the course of the design. This could result in prematurely terminated designs that do not meet the CDF=1 design criterion. In version 1.204, the algorithm is changed so that the iteration count automatically restarts if the program changes the rigid pavement subbase thickness.