A review of design and fabrication strategies for thermoplastic lightweight thin-walled stiffened shells and lattice structures utilizing fused-filament fabrication (FFF)

The demand for lightweight and mechanically reliable structures has motivated increased interest in Additive Manufacturing (AM), particularly Fused Filament Fabrication (FFF), while underscoring the importance of an integrated understanding of the design-to-fabrication workflow. While numerous studies have focused on individual aspects of the FFF process in fabrication of such structures, detailed review linking design strategies, optimization techniques, and manufacturing challenges are scarce. This work addresses that gap by reviewing current strategies for designing and fabricating lightweight structures using FFF. First, it investigates sophisticated design and optimization strategies, consisting of Design for Additive Manufacturing (DfAM) concepts and Topology Optimization (TO) techniques specifically adapted for thin-walled and lattice structures. The limitations of traditional CAD tools are extensively investigated along with a summary of major manufacturing challenges. The review combines multidisciplinary insights to create an integrated understanding for generating structurally efficient and reliable FFF components. It concludes by outlining prospective future research avenues, including artificial intelligence–driven process control and digital twins for predictive modeling. This work offers a detailed resource for researchers and practitioners aiming to address existing limitations and drive FFF towards resilient next-generation lightweight systems.