11:00
Session 2: Trajectories for Automated Fiber Placement
Chair: Brian Tatting
11:00
20 mins
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Fibre Path Planning for Automated Fibre Placement on Doubly Curved Structures
Avyadhish Malladi, Christos Kassapoglou, Daniël Peeters
Abstract: Variable-stiffness laminates, enabled by automated fibre placement, offer improved structural performance through spatially varying fibre orientations. A three-step design framework comprising stiffness optimisation, fibre angle retrieval, and fibre path generation has been developed to realise such laminates, of which fibre path generation is the subject of this work. Doubly curved geometries with Gaussian curvature are predominant in aerospace structures, yet extracting streamline-based courses at prescribed spacing on such surfaces remains insufficiently addressed in the literature. This paper proposes a geodesic course extraction method that guarantees overlap-free placement on curved surfaces, with gaps tolerated as a design concession, demonstrated on a doubly curved geometry.
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11:20
20 mins
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Layup Strategies for in-situ Automated Fiber Placement of Complex Geometries
Lukas Raps, Ashley Chadwick, Heinz Voggenreiter
Abstract: With meticulous process control and the correct manufacturing parameters, autoclave-level mechanical properties have been proven to be achievable using in-situ Automated Fiber Placement (AFP). This long-awaited result at the coupon level has spurred the use of AFP for larger structural components for structures. However, the complex geometries, particularly double curvatures required for real part geometries, present additional obstacles to the already challenging process. Without post-consolidation in a hot press or autoclave, the severity of geometry-related deviations from the ideal ply composition, namely fiber angle defects or tow-drops, remains unquantified.
This work presents a systematic derivation of layup deviations which inevitably arise for tape placement on complex geometries. Ply layup simulation software and analytical Python scripts are used and the triangular correlation between the three deviation types (steering defects, gaps/overlaps and angle deviation) is demonstrated. Layup strategies are developed specifically for the characteristics of the in-situ AFP process. Three complex example geometries are investigated as case studies: A Variable Stiffness Panel (VSP), a spherical hydrogen tank structure and a complex double-curved fuselage section. A spherical hydrogen tank section is manufactured as a validation experiment (Figure 1).
The results of this study show that increasing the number of parallel tows generally elevates angle deviation and critical steering radii while reducing area related coverage defects; an optimal design can therefore be pursued by maximizing parallel tows within process dependent limits (e.g., ±3° angle deviation for thermoset AFP). Simulation reveals that steering radii can drop to as low as 100 mm for spherical domes and 500 mm for the investigated fuselage sections, with gaps and overlaps varying from 100 mm to several meters depending on geometry and layup.
This work presents detailed correlations between layup strategy parameters and the resulting layup deviations, providing algorithms for optimized layup strategies for in-situ AFP on complex geometries.
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11:40
20 mins
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Rule-based app tape path design for aerospace composite structures a geometry-classified manufaturability assessment
Julian Schuster, Maximilian Holland
Abstract: This paper presents a rule-based methodology for the design and manufacturability assessment of Automated Fiber Placement (AFP) tape path strategies for aerospace composite structures. A geometry classification framework based on Gaussian curvature is introduced and applied to two representative classes: Flat plates as a kinematic process reference and developable C-frame profiles as the primary case study. Parametric manufacturing studies evaluate layup rate, steering quality, gap and overlap coverage, and fiber angle deviation across multiple fiber orientations and path planning strategies. The comparison between direct 3D tool layup and 2D flat preform manufacture reveals rate improvements of up to 101%, and a holistic strategy assessment identifies constant direction and involute paths as complementary solutions addressing productivity and coverage quality respectively.
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12:00
20 mins
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Continuous Trajectory Generation for the Automated Manufacturing of Super-Ellipsoidal Composite Pressure Vessels
Gregorio Ferreira, Shahrzad Daghighi, Giovanni Zucco, Paul Weaver
Abstract: The demand for lightweight, high-performance composite structures has accelerated the adoption of automated fibre and tape placement technologies. However, manufacturing doubly curved geometries with non-conventional tow steering remains challenging due to the need for smooth, feasible, and robot-compatible trajectories. This work presents an integrated methodology for generating continuous AFP/LATP paths on super-ellipsoidal composite vessels using carbon-thermoplastic tape deposition. The framework transforms structural design prescriptions into continuous surface-embedded trajectories by combining analytical super-ellipsoidal geometry with a robust Darboux-frame formulation, which provides smooth tangent-normal-geodesic normal evolution and ensures a non-singular tool-frame definition across the entire surface. A polar-opening clipping algorithm enforces precise termination of all paths, while a closed-form inter-tape gap law quantifies coverage, overlap, and multi-pass behaviour across the full vessel surface. The entire methodology is implemented in MATLAB as a single, unified codebase that automates path generation and coverage assessment. The present work focuses exclusively on path planning and coverage evaluation, providing a coherent computational basis for generating continuous steered trajectories and quantifying inter-tape coverage on super-ellipsoidal vessels.
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