R. Cook, P.-Y. Lavertu
Keywords: ICME, material modeling, digital twin, digital thread, multiscale, simulation, prediction, smart factory, AFP, automated fiber placemnet, composites
Summary:Automatic Fiber Placement (AFP) is a fast and efficient deposition process of carbon prepreg for large component applications. To accommodate the composite strips onto a double curved surface, the tows can be cut, restarted and slightly mis-oriented resulting in the apparition of gaps between tows. These defects, the gaps and the misalignment of the tows, affect the mechanical performance of the final part. The Robots that execute that deposition of tow are driven by control software; this software serves as the link between the as-designed and the as-manufactured part. To assess and screen expected performance of the as-processed part, including the effects of the presence of defects, an additional link between the as-manufactured and the as-designed part must be introduced. Recent developments in the Digimat multi-scale material modeling solution now contain tools to predict the performance of as-processed parts produced via AFP, using information directly from the robot control software. The development consists of reading information such as the localization of gaps and the as-manufactured fiber orientation, and to transfer such information onto the finite element mesh used for structural analysis simulations. During stress analysis of the component, Digimat then uses a micromechanical model to compute the local material properties by considering the presence or absence of tows and the local fiber orientation. To close the loop, in-line inspection can be conducted to measure in-situ the tape placement direction for a more accurate assessment of the part performance.