Search Results

One of the most common damages occurred found on commercial airframes are dents and gouges. The usual repair for these damages includes installation of metallic doublers with rivets or with hi-loks. Sometimes these doublers are of complex design, because of multiple angles of the original damaged skin. Many times the damages are in hard to reach areas. In these cases the traditional metallic doubler repairs are not only time consuming and but also expensive. As the numerous holes are be drilled through the original structure, its fatigue life is adversely affected. For airline operators, time is valuable and they cannot afford to lose revenue by spending longer time for repairs. The use of bonded composite doublers offers the airframe manufacturers and aircraft repair facilities an alternative repair process that alleviates the abovementioned concerns.

With the increasing usage of composites for aerodynamic surfaces, the use of bonded composite repair processes are becoming more common. The repair process remains a largely manual process, with repair technicians scarfing or stepping, tracing the plies, fabricating repair patches and finally bonding the patch. The patch fabrication process becomes increasingly tedious and tiring due to cutting and tracing of each individual ply twice for thermal surveying and the final repair patch. We have developed a system that can replace the tracing and cutting components of the fabrication process using low cost, commercial off the shelf (COTS) tools. We present the ply boundary extraction method used and detail the nesting algorithm used to produce the final plies. Our software is benchmarked against the manual process with a list of successfully cut materials using a low cost fabric cutter with a steel drag blade.