Multi-material four-dimensional (4D) printing has gathered significant interest among researchers as an emerging manufacturing technique. In this study, continuous carbon fibers are integrated into shape memory polymers (SMPs) using multi-material co-extrusion 4D printing. This process results in the creation of shape memory polymer composites (SMPCs) characterized by high load-bearing capacity and stimulus responsiveness. Micro-CT scanning is employed to evaluate the internal porosity of SMPCs, based on which the three-dimensional (3D) reconstruction images are generated. Meanwhile, various mechanical tests are implemented, including tensile, three-point bending, and compression tests, to explore the mechanical properties and fracture modes of the 4D printed SMPCs. In addition, the shape memory effect of the 4D printed SMPCs is verified by experiments and finite element simulations. The results demonstrate shape recovery rates higher than 96%. This study offers valuable insights into the fabrication and testing of smart composites with compatible deformation and high load-bearing capacity.

中文翻译：

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4D打印连续纤维增强形状记忆聚合物复合材料，具有增强的机械性能和形状记忆效应

多材料四维（4D）打印作为一种新兴的制造技术引起了研究人员的极大兴趣。在这项研究中，使用多材料共挤出 4D 打印将连续碳纤维集成到形状记忆聚合物 (SMP) 中。该过程产生了具有高承载能力和刺激响应能力的形状记忆聚合物复合材料（SMPC）。采用微型 CT 扫描来评估 SMPC 的内部孔隙率，并在此基础上生成三维 (3D) 重建图像。同时，还进行了各种力学测试，包括拉伸、三点弯曲和压缩测试，以探索4D打印SMPC的力学性能和断裂模式。此外，4D打印SMPC的形状记忆效应通过实验和有限元模拟得到验证。结果表明形状恢复率高于 96%。这项研究为具有兼容变形和高承载能力的智能复合材料的制造和测试提供了宝贵的见解。