Abstract This study is focused on the low-velocity impact response of 3D plate-lattices fabricated via stereolithography additive manufacturing (AM). Elementary (SC, BCC and FCC) and hybrid (SC-BCC, SC-FCC and SC-BCC-FCC) configurations were tested and the effects of impact energy, relative density, plate-thickness, multiple impacts and impact angle on the dynamic crushing behavior and energy absorption characteristics were analyzed. The experimental results reveal that the hybrid lattices, due to the existence of larger number of open and closed sub-cells, were able to attenuate the peak impact stress transmitted to the structure and extend the duration of the load pulse (high toughness). A significant energy dependency of contact force-displacement characteristics of hybrid structures was noticed with increase in impact energy. The SC-BCC-FCC hybrid plate-lattices depicted a 70% increase in toughness and their specific energy absorption capacity is higher than the conventional aluminum lattices and other practical metamaterials. Experimental observations also revealed that the distribution of plates in each elementary structure in hybrid configuration plays an important role in mitigating the deleterious failure mode by transforming the brittle mode fracture into progressive damage of the plate-lattices. This paper, believed to be the first comprehensive experimental study, discusses the role of relative density, plate-thickness, multiple impacts, impact energy and oblique impact on the low velocity impact response of geometrically hybridized plate-lattice structures. The results of this investigation suggest that the concept of hybridization of plate-lattice architectures in conjunction with AM will enable development of lightweight high impact energy absorbing structures for a wide variety of applications.

中文翻译：

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低速冲击载荷下增材制造板格的能量吸收特性

摘要 本研究的重点是通过立体光刻增材制造 (AM) 制造的 3D 板格的低速冲击响应。测试了基本（SC、BCC 和 FCC）和混合（SC-BCC、SC-FCC 和 SC-BCC-FCC）配置，并测试了冲击能、相对密度、板厚、多次冲击和冲击角度对动力学的影响分析了破碎行为和能量吸收特性。实验结果表明，混合晶格由于存在大量开放和封闭的子单元，能够衰减传递到结构的峰值冲击应力并延长载荷脉冲的持续时间（高韧性）。随着冲击能量的增加，注意到混合结构的接触力-位移特性的显着能量依赖性。SC-BCC-FCC 混合板晶格的韧性提高了 70%，其比能量吸收能力高于传统的铝晶格和其他实用的超材料。实验观察还表明，混合配置中每个基本结构中的板分布在通过将脆性模式断裂转化为板格的渐进损伤来减轻有害失效模式方面起着重要作用。这篇论文被认为是第一个综合实验研究，讨论了相对密度、板厚、多次冲击、冲击能量和斜向冲击对几何混合板格结构低速冲击响应的作用。