COMPLIANT COMPOSITE PART MACHINING

The manufacturing process for composite parts often requires machining operations. The machining operations are created in the CAD system from a nominal geometric definition. Complex composites often exhibit the result of residual internal stresses from the curing process, or from other process parameters. These stresses frequently result in twist, bow, or other geometric variation in the final product. For components that require precise machine operations, these variations frequently exceed the machining tolerances such that a nominal NC machine path does not match the part, resulting in feature mislocation, or undercut or overcut areas. The result is increased labor to locate and drill holes manually and to rework overcut areas. Undercutting often results in scrapped parts. A system has been developed that probes the cured shape of a composite part, and then variably adjusts the NC data to make it comply with the part. This new process will eliminate manual operations and rework, as well as eliminate scrap due to undercutting. The benefits consist of increased throughput, reduced labor costs, and reduced scrap.