Shape Compensation of Large-Scale Additive Manufactured Composite Tooling

Conference Abstract: Extrusion Deposition Additive Manufacturing (EDAM) with fiber reinforced thermoplastics has been widely demonstrated for applications including non-structural vehicle components, sculptures, and in tooling for operations at ambient and elevated temperature. The Large-Scale Additive Manufacturing (LSAM) process is a form of EDAM that provides deposition rates of up to 220 kg/hr, which enables rapid fabrication of multi-meter long tooling for producing composite parts in the aerospace, automotive, wind energy, and marine industries. However, the intrinsic characteristics of fiber reinforced composite material, which are highly anisotropic, and the non-isothermal nature of additive manufacturing produce stresses that can produce deformation and delamination of the printed geometry. This motivated the development of the physics-based virtual twin for additive manufacturing, ADDITIVE3D, which provides predictions of residual stresses, deformation, interlayer bonding, and potential for delamination. In addition, this virtual twin enables performance investigation of the as-printed state, namely considering effects of manufacturing such as residual stresses, global material orientation, interlayer bonding developed during printing. Prediction and compensation of shape change due to printing, machining, and during the operation of printed autoclave tooling at temperatures of up to 180 °C is of paramount importance for the successful implementation of this technology. Hence, this study demonstrated the entire process of shape compensation for additively manufactured carbon fiber reinforced composite autoclave tooling. The study addresses each occurrence of shape change and compensates for the tool geometry all the way from laminate shape change analysis, compensated tool nominal shape design, to shape change during the printing process. Simulation results were validated against experimental measurements of an autoclave tool and through the fabrication a composite part using the tool. The tool and part shape were measured using topography 3D laser scanning and compared with the simulation results.