Compressive behaviour of 3D printed thermoplastic polyurethane honeycombs with graded densities
Compressive behaviour of 3D printed thermoplastic polyurethane honeycombs with graded densities
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DOI：
10.1016/j.matdes.2018.11.019
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发表时间：
2019-01-15
影响因子：
8.4
通讯作者：
Trask, Richard S.
中科院分区：
文献类型：
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作者：
Bates, Simon R. G.;Farrow, Ian R.;Trask, Richard S.
熔丝制造热塑性聚氨酯(TPU)提供了一种制造可定制、灵活的蜂窝结构的能力，这种结构可以优化用于能量吸收应用。这项工作探索了一系列分级方法对柔性热塑性聚氨酯蜂窝结构吸能和减震性能的影响。通过应用密度分级，能量吸收和阻尼型比均匀密度当量有了显著的改变。开发了一种3D打印程序，可以制造高质量的结构，从循环加载到致密而不会失败。分级蜂窝结构的平均相对密度为0.375+/-0.05。在准静态测试后，阵列在0.5赫兹的幅度范围内受到正弦压缩。通过不同方式对结构密度进行分级，对机械阻尼进行了修正。循环压缩试验还表明，在50个循环过程中，TPU母材的应变软化如何导致减振。样品承受高达51 S应变率(-1)的冲击载荷和高达270MJ/cm(3)的比冲击能。对于最严重的冲击情况，分级样本转移了较低的峰值载荷。这一行为揭示了热塑性聚氨酯结构密度分级的潜力，以在极端环境条件下提供卓越的冲击保护。(C)2018年作者。由爱思唯尔有限公司出版。这是一篇在CC by License(http://creativecommons.org/licenses/by/4.0/).下的开放获取文章
Fused filament fabrication of thermoplastic polyurethanes (TPUs) offers a capability to manufacture tailorable, flexible honeycomb structures which can be optimised for energy absorbing applications. This work explores the effect of a range of grading methodologies on the energy absorbing and damping behaviour of flexible TPU honeycomb structures. By applying density grading, the energy absorbing and damping profiles are significantly modified from the uniform density equivalent. A 3D-printing procedure was developed which allowed the manufacture of high-quality structures, which underwent cyclic loading to densification without failure. Graded honeycomb architectures had an average relative density of 0.375 +/- 0.05. After quasi-static testing, arrays were subjected to sinusoidal compression over a range of amplitudes at 0.5 Hz. By grading the structural density in different ways, mechanical damping was modified. Cyclic compressive testing also showed how strain-softening of the TPU parent material could lead to reduced damping over the course of 50 cycles. Samples were subjected to impact loading at strain-rates of up to 51 s(-1) and specific impact energies of up to 270 mJ/cm(3). Lower peak loads were transferred for graded samples for the most severe impact cases. This behaviour reveals the potential of density grading of TPU structures to provide superior impact protection in extreme environmental conditions. (c) 2018 The Authors. Published by Elsevier Ltd. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/).