Different from conventional unidirectional outward-inward forming methods, this study employs a multidirectional internal expansion shaping approach to fabricate lightweight sandwich composite tubes. Integrating carbon fiber reinforced polymer (CFRP), thermal expansion foam and polymethacrylimide (PMI) foam, the sandwich composite tubes demonstrate adaptability in terms of material properties as validated through several experimental trials. The one-step molding process eliminates the requirements for subsequent structural assembly and bonding, while ensuring adhesion between diverse material components. The sandwich composite tubes exhibit superior impact resistance, showcasing a stable progressive crushing failure. The energy absorption mechanism shifts from single CFRP damage to a multi-material composite energy absorption mode. The specific energy absorption (SEA) value of designed sandwich composite tube is up to 102 J/g. The sandwich composite tubes fabricated in this study hold promising applications in advanced vehicle/aerospace lightweighting and crashworthiness safety.

中文翻译：

---

通过新设计的内部热膨胀技术制造的轻质夹层复合材料管的准静态挤压响应

与传统的单向向外向内成形方法不同，本研究采用多向内膨胀成形方法来制造轻质夹层复合材料管。夹层复合管集成了碳纤维增强聚合物（CFRP）、热膨胀泡沫和聚甲基丙烯酰亚胺（PMI）泡沫，通过多次实验验证，证明了材料性能的适应性。一步成型工艺消除了后续结构组装和粘合的要求，同时确保了不同材料组件之间的粘合力。夹层复合管表现出优异的抗冲击性，表现出稳定的渐进式破碎破坏。吸能机制由单一CFRP损伤转变为多材料复合吸能模式。设计的夹层复合管的比能量吸收（SEA）值高达102 J/g。本研究中制造的夹层复合管在先进车辆/航空航天轻量化和耐撞安全性方面具有广阔的应用前景。