Demonstration and. 4. Contact List. Federal Aviation Administration. Administration

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1 Demonstration and Hands-On Training Presented to: VII ALACPA Airport Pavement Seminar & V FAA Airport Pavement Workshop By: David R. Brill, P.E., Ph.D. Date: Information on Disk 1. FAA Computer Programs i. ii. LEDFAA 1.3 iii. FEAFAA 1.4 iv. BAKFAA v. COMFAA 2.0/COMFAA 3.0 & Equivalent Traffic Spreadsheet vi. ProFAA 2. Advisory Circulars i. 150/5320-6E Airport Pavement Design & Evaluation ii. 150/5320-6D: Airport Pavement Design & Evaluation (CANCELLED) iii. 150/5335-5A and 150/5335-5B (Draft): Standardized Method of Reporting Airport Pavement Strength PCN iv. 150/ D: Standards for Specifying Construction of Airports v. 150/ A: Use of Nondestructive Testing in the Evaluation of Airport Pavements vi. 150/5380-9: Guidelines and Procedures for Measuring Airfield Pavement Roughness 3. FAARFIELD Workshop Presentations 4. Contact List 2

2 Acknowledgments FAA NAPTF: Support Contractor SRA Dr. Satish K. Agrawal Jeff Gagnon Dr. Gordon F. Hayhoe Dr. Navneet Garg Qingge Jia FAA HQ Chuck Teubert Dr. Izydor Kawa Dr. Qiang Wang Dr. Yuanguo Chen Consultants: Jeff Rapol Dr. Edward H. Guo Roy D. McQueen Richard Ahlvin 3 Airport Technology R&D Program Research conducted at the FAA William J. Hughes Technical Center, Atlantic City, NJ, USA. Sponsor: FAA Office of Airport Safety and Standards (AAS-100), Washington, DC. Provide support for development of FAA pavement standards (Advisory Circulars). 4

3 National Airport Pavement Test Facility (NAPTF) FACTS: Fully enclosed facility for accelerated traffic testing of airport pavements. Full-scale pavement structures and landing gear loads with programmed wander. Opened in Total construction ti contract t was $21M. $14M from FAA $7M from Boeing Co. under FAA/Boeing CRDA. 5 FAARFIELD What Is It? Federal FAARFIELD is the new FAA airport pavement Aviation thickness design program. Rigid and FAARFIELD supersedes LEDFAA Flexible 1.3 as the standard Iterative design procedure in FAA Advisory Circular Elastic (AC) 150/5320-6E. Layered Officially released Design September 30,

4 Computer program for desktop PCs. Program preserves the look and feel of LEDFAA 1.3. Major changes are internal. Main program drives three subprograms: LEAF (layered elastic analysis) NIKE3D (3D finite element analysis) INGRID (3D mesh generation) 7 FAA Legacy Design Procedures vs. LEDFAA 1.3 AC 150/5320-6D LEDFAA 1.3 (Chapters 3-4) Traffic Model Structural Response Models Thickness Design Method Implementation All traffic converted to equivalent departures of design aircraft Westergaard s solution for rigid pavements Boussinesq model used to compute ESWL for flexible CBR equation with alpha factor (flexible) Apply percent of thickness to basic design for 5000 coverages (rigid) Design nomographs (spreadsheet implementation also available) CDF (Cumulative Damage Factor) accounts for mixed traffic Layered elastic analysis (LEAF) for flexible and rigid Failure model relates coverages to structural t failure to a suitable response: subgrade strain (flexible) or concrete stress (rigid). Desktop computer program 8

5 FAA Legacy Design Procedures vs. FAARFIELD AC 150/5320-6D (Chapters 3-4) Traffic Model Structural Response Models Thickness Design Method Implementation All traffic converted to equivalent departures of design aircraft Westergaard s solution for rigid pavements Boussinesq model used to compute ESWL for flexible CBR equation with alpha factor (flexible) Apply percent of thickness to basic design for 5000 coverages (rigid) Design nomographs (spreadsheet implementation also available) CDF (Cumulative Damage Factor) accounts for mixed traffic Layered elastic analysis (LEAF) for flexible. 3D finite element for rigid. Failure model relates coverages to structural t failure to a suitable response: subgrade strain (flexible) or concrete stress (rigid). Desktop computer program Visual Studio FAARFIELD Technical Background Computer program for desktop PCs. Program preserves the look and feel of LEDFAA 1.3. Major changes are internal. Main program drives three subprograms: LEAF (layered elastic analysis) NIKE3D (3D finite element analysis) INGRID (3D mesh generation) NIKE3D and INGRID information: Modified for FAARFIELD by the FAA Distributed in compiled form under a software sharing agreement with Lawrence Livermore National Laboratory (LLNL) 10

6 Key Differences from LEDFAA 1.3 Rigid Pavements/Overlays Slab edge stresses are now computed directly using 3D-FEM. Completely revised rigid pavement failure model. Rewrote and improved rigid overlay design procedures. Flexible Pavements/Overlays Automatic base thickness design. Improved Pass-to-Coverage ratio computation routine. Supports HMA overlay design on rubblized PCC base. General Upgrade to MS Visual Basic 2005 programming environment. Aircraft library updated. New function allows user to export design data to XML. Improved formatting for Notes. All user options collected on one Options screen. 11 Pavement thickness is now computed for constant t tire contact t area. Changing the airplane gross weight causes the tire pressure to be adjusted to maintain the contact area. External aircraft library in XML format. Displays CDF values graphically. Enhanced Airplane Data window now displays gear coordinates. Support for PCC over rubblized base. Aircraft changed to Airplane(s). 12

7 Cumulative Damage Factor (CDF) Sums the damage contributed from each aircraft - not from equivalent aircraft. CDF = Σ (n i /N i ), where: n i = actual passes of individual aircraft i N i = allowable passes of individual aircraft i When CDF = 1, design life is exhausted. In FAARFIELD (and LEDFAA 1.3): The gear location and wander are considered separately for each aircraft in the total mix. CDF is calculated for each 25.4 cm (10 inch) wide strip over a total m (820 inch) width. Miner s rule to sum damage for each strip. Must input the fleet mix, NOT equivalent departures of design aircraft. 13 Cumulative Damage Factor (CDF) Difference in Gear Location CDF Damage from Airplane A Damage from Airplane B 25.4 cm (10 in.) 14

8 Cumulative Damage Factor (CDF) 25.4 cm (10 in.) Total Damage CDF Damage from Airplane A Damage from Airplane B 15 Large Airplane Traffic Mix Gear Locations Centerline e. Runway B B A-330 B A-300-B2 B-757 B-727 B MD-83 MD DC-9-50 DW 100,000 Regional Jet 700 Regional Jet 200 DW 45,000 DW 30,000 SW 30, Distance From Centerline (in) 16

9 FAARFIELD CDF Graphical Display 17 Remember - in FAARFIELD Use the entire traffic mix! 18

10 FAARFIELD System/Software Requirements Minimum Windows MHz Pentium III processor 256 MB memory Recommended Windows XP 2 GHz Pentium IV processor 512 MB memory Users of older operating systems 600 MHz Pentium III processor 2 GHz Pentium IV processor 200 MB of available space on hard drive. may require a one-time Users of older operating systems may require a one-time installation ti of the.net Microsoft). Framework (free download from Microsoft). installation of the.net Framework (free download from Microsoft) 19 Running FAARFIELD: Program Windows and Linkage NOTES Additional Section Information and Detailed Output Data STARTUP Control and Organization OPTIONS Set User Options and Tolerances Export XML STRUCTURE Structure Data Input and Design AIRCRAFT Aircraft Load and Traffic Data Input AIRCRAFT DATA View Landing Gear Geometry, Load, and Tire Pressure 20

11 FAARFIELD Input Requirements Structure Window For each structural layer: Material type (FAA specification) Layer Thickness Modulus or R-value (if applicable) There are built-in restrictions on the layer types, including relative position and layer properties. For subgrade, can enter CBR or k and FAARFIELD will convert to E. Aircraft Window Select airplane from library. For each airplane in the mix: Aircraft Name Gross Taxi Weight Annual departures and percent annual growth if applicable Enter data for all airplanes in the mix. 21 FAARFIELD External Files New Flexible Pavements Flexible Overlays on Flexible Pavements New Rigid Pavements, Rigid Overlays on Rigid Pavement Flex Overlays on Rigid Pavement LeafSG.out Subgrade layer responses NikePCC.out Stresses at the bottom for flexible pavement. of PCC layer. LeafAC.out HMA surface layer Nike3d.txt 3D finite element summary responses for a flexible pavement. output file. n3dhsp 3D finite element detailed Common Files output file. Storage files: *.JOB.xml job files (XML format) Legacy Files contain data required by FAARFIELD for all the sections in one job. *.DES.xml design information files generated by Save XML command. *.nts notes files (contain user entered information) Help file: faarfield.chm. External airplane file: FAAAirplaneLibrary.xml Leaf.loa and Leaf.str Load and structure definition files compatible with programs LEDNEW and Juleaww.exe 22

12 FAARFIELD Job Files (JOB.xml) Job files in FAARFIELD 1.2 are in XML format. This is a different format than previous job files in LEDFAA. FAARFIELD looks for old job files in the working directory and automatically converts them to the new XML format. After reading, the old job files are moved to a subdirectory of the working directory called old_job_files. All subsequent changes are written to the JOB.xml files only. The old job files are not changed. 23 Structural Models in Both layered elastic (LEAF) and 3D-FEM (NIKE3D) are used in FAARFIELD. Flexible pavement design LEAF is used for all structural computations. For flexible, no advantage to using 3D-FEM. Rigid pavement design LEAF is used to generate a preliminary thickness. Final iterations ti are done using 3D-FEM. E 1, ν 1 E 2, ν 2 E 3, ν 3 2a q h 1 h 2 24

13 3D-FEM Rigid Pavement Mesh Displayed Using NikePlot Utility Model includes 1 or 2 slabs (i.e., base PCC and overlay) Multiple l Base Layers Not Visible to the User During Design Subgrade ( Infinite Elements) 25 3D-FEM Stress Response Stress σ yy Contours Displayed Using NikePlot 3D-FEM responses are not visible to the user during design. 26

14 Questions? 27