Although 3D woven composites have exceptional out-of-plane properties, there is a lack of understanding for these materials in crash application in automotive and aerospace industries. To encourage the use of 3D wovens in crashworthy automotive structures, knowledge must be gained so that designers can adjust the highly flexible weave parameters to create tailor-made performance materials. Here we show that fabric pick density causes large changes in progressive failure modes and associated energy absorption, particularly in the dynamic regime, where the quasi-static to dynamic energy absorption loss typical of composites is completely removed. Compression and flexure properties, which are known to be linked to crash performance in composites, are also investigated for these 3D woven layer-to-layer interlock carbon-epoxy composite structures. 3D fabric preforms are manufactured in three different pick densities: 4, 10 & 16 wefts/cm. With a constant warp density of 12 warps/cm from carbon fibres. Increasing the pick density improved specific energy absorption (SEA) even in relatively inefficient progressive failure modes like folding, which has not previously observed in composite materials. SEA values up to 104 J/g (quasi-static) and 93 J/g (dynamic) are recorded. This work shows that minor weft direction (transverse) weave changes can lead to sizeable improvements in warp direction (axial) energy absorption without fundamentally redesigning the weave architecture.

尽管3D编织复合材料具有出色的平面外性能，但对于这些材料在汽车和航空航天行业的碰撞应用中仍然缺乏了解。为了鼓励在防撞汽车结构中使用3D编织物，必须获得知识，以便设计人员可以调整高度灵活的编织参数以创建量身定制的性能材料。在这里，我们表明织物的纬纱密度会引起渐进式破坏模式和相关能量吸收的较大变化，尤其是在动态状态下，复合材料典型的准静态到动态能量吸收损失被完全消除。对于这些3D编织层到层互锁碳-环氧复合材料结构，还研究了与复合材料的耐撞性能有关的压缩和弯曲性能。3D织物预成型坯以三种不同的拾取密度制造：4、10和16纬/厘米。碳纤维的恒定经线密度为12经线/厘米。甚至在相对低效的渐进破坏模式（如折叠）中，提高拾取密度也可以改善比能量吸收（SEA），这在复合材料中以前是没有发现的。记录的SEA值高达104 J / g（准静态）和93 J / g（动态）。这项工作表明，较小的纬向（横向）织造变化可以导致经向（轴向）能量吸收得到较大改善，而无需从根本上重新设计织造结构。甚至在相对低效的渐进破坏模式（如折叠）中，提高拾取密度也可以改善比能量吸收（SEA），这在复合材料中以前是没有发现的。记录的SEA值高达104 J / g（准静态）和93 J / g（动态）。这项工作表明，较小的纬向（横向）织造变化可以导致经向（轴向）能量吸收得到较大改善，而无需从根本上重新设计织造结构。甚至在相对低效的渐进式破坏模式（如折叠）中，拾取密度的提高也改善了比能量吸收（SEA），这在复合材料中以前没有观察到。记录的SEA值高达104 J / g（准静态）和93 J / g（动态）。这项工作表明，较小的纬向（横向）织造变化可以导致经向（轴向）能量吸收得到较大改善，而无需从根本上重新设计织造结构。