Welcome to the official home page of CRAS, the USAF's composite patch analysis program. The CRAS software is a windows application used to quickly design and analyze composite patches for relatively flat aircraft structures. Patch parameters are entered into a windows interface, and the software calculates an acceptable patch design. The design manual portion of CRAS may be used independently of the software for patch design and analysis. The software can be used for different types of damage: cracks, corrosion grind-outs, holes with grind-outs, holes, dents, and cutouts. The software also computes thermal and bending effects and crack growth fracture analysis. CRAS includes three modules: the initial design tool based on simple closed-form solutions; a refined closed-form analysis tool that computes stress, crack-tip stress intensity factors, and adhesive strains; and a rapid FEM tool (PatchGen) that facilitates creation of a NASTRAN or ABAQUS model by generating a PATRAN session file. Users: Please use the forum located at http://www.siresearch.info to report bugs or suggest changes to the code. New Users: CRAS cannot be downloaded at the current time from this site.