摘要: |
FEDFAA, Finite Element DesignFederal Aviation Administration, is a computer program for both airport rigid and flexible pavement thickness design. NIKE3D (a general-purpose, three-dimensional finite element method (3D-FEM) computer program) is the selected engine for critical stress calculation for airport rigid pavement design. The calculated edge stresses are used in the FEDFAA failure model to determine the slab thickness. Since FEDFAA is a tool for thickness design rather than for analysis, certain program modifications and selection of available elements in NIKE3D have been made during FEDFAA development; it includes (1) selection of the nonconforming eight-node solid element to model all layers of the pavement except the subgrade, (2) introduction of the infinite element to model the infinitely deep subgrade, (3) mesh densities in vertical and horizontal directions, and (4) slab size and width of subbase extension have been determined to fit the needs of the design. A procedure has also been developed to calculate the critical stress of the pavement from the stresses calculated by NIKE3D at the element Gaussian points. / NOTE: Final rept. / Supplementary Notes: Sponsored by Federal Aviation Administration, Washington, DC. / Availability Note: Order this product from NTIS by: phone at 1-800-553-NTIS (U.S. customers); (703)605-6000 (other countries); fax at (703)605-6900; and email at orders@ntis.gov. NTIS is located at 5285 Port Royal Road, Springfield, VA, 22161, USA. |