This paper presents the state-of-the-art of additive manufacturing of composites for processing functional, load-bearing components. A general overview of different additive manufacturing methods is provided, and specific attention is focused on fused filament fabrication-based composites processing. Different process modeling strategies are summarized, and key aspects of these models are discussed. Significant results such as thermal and fluid flow characteristics, effects of nozzle geometry on melt flow, fiber orientation, bead spreading, and solidification, the formation of residual stresses, and deformation behavior are discussed from computational modeling perspective. The scientific advancement, model limitations, and future modeling needs are prescribed reviewing the current works. A general overview of material development in nano-micro-macro-scale reinforcement is also presented. Different length-scales of reinforcement has its own challenges and promises. The continuous fiber reinforcement has a great potential for being the next-generation composites manufacturing technology. However, the challenges in reducing the void content, better bonding between the fiber–matrix, and layer-layer adhesion, and process uncertainty are some of the key areas yet to advance. Based on the current limitations on computational modeling, materials development, and process modeling studies, future research needs and recommendations are provided.

中文翻译：

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复合材料的工艺模型、结构-性能关系及熔丝制造的未来需求回顾

本文介绍了用于加工功能性承重部件的复合材料增材制造的最新技术。提供了不同增材制造方法的一般概述，并特别关注基于熔丝制造的复合材料加工。总结了不同的过程建模策略，并讨论了这些模型的关键方面。从计算建模的角度讨论了诸如热和流体流动特性、喷嘴几何形状对熔体流动、纤维取向、珠粒扩散和凝固、残余应力的形成和变形行为的影响等重要结果。审查当前工作规定了科学进步、模型限制和未来的建模需求。还介绍了纳米微观宏观尺度增强材料发展的一般概述。不同长度尺度的强化有其自身的挑战和承诺。连续纤维增强材料具有成为下一代复合材料制造技术的巨大潜力。然而，减少空隙含量、更好地结合纤维-基体、层间粘合以及工艺不确定性方面的挑战是一些尚未取得进展的关键领域。基于当前在计算建模、材料开发和过程建模研究方面的局限性，提供了未来的研究需求和建议。连续纤维增强材料具有成为下一代复合材料制造技术的巨大潜力。然而，减少空隙含量、更好地结合纤维-基质和层间粘合以及工艺不确定性方面的挑战是一些尚未取得进展的关键领域。基于当前在计算建模、材料开发和过程建模研究方面的局限性，提供了未来的研究需求和建议。连续纤维增强材料具有成为下一代复合材料制造技术的巨大潜力。然而，减少空隙含量、更好地结合纤维-基质和层间粘合以及工艺不确定性方面的挑战是一些尚未取得进展的关键领域。基于当前在计算建模、材料开发和过程建模研究方面的局限性，提供了未来的研究需求和建议。