A study on dimensional deviations in the manufacturing process of carbon fiber reinforced composite structures in aerial platforms: A tool design perspective

Composite parts with carbon fiber reinforced thermoset matrix structure, which are used especially in primary structures in the aviation industry, differ from the design geometries after the production processes, causing high-cost losses in structural assembly activities and consequences that threaten flight safety during the usage phases of aircraft. The types of divergence from design geometry observed in literature depending on part shape and the classification of intrinsic and extrinsic factors affecting these deformations were examined. In this thesis study, deformation calculations were carried out using analytical methods found in literature for an "L" shaped test piece geometry with a single bend at a 90° angle, made of AS4/8552 material and the deformation that would occur due to intrinsic factors was predicted. In the experimental study part, four molds were prepared using four different tool materials to produce 24 test specimens by keeping the intrinsic factors constant. In addition to the process induced deformations caused by intrinsic factors, the analytical formulation expanded to include mold parameters which are considered as an extrinsic factor. The deformation differentiations resulting from the production of parts with the same intrinsic parameters in male and female molds are compared. A mold compensation factor calculation method has been proposed to be used in the design phase of the tools in order to provide convergence to the part design geometries.