Abstract Polyurethane foam (PUF) has excellent thermal insulation performance owing to its closed cellular solid structure. Additionally, this microstructural characteristic provides outstanding impact absorption performance. Owing to these advantages, PUF is widely adopted in transportation applications. From the viewpoint of use in practical applications, it is necessary to evaluate the residual strength after repetitive low-energy impacts on the structure. Thus, in the present study, we investigated the effects of repetitive low-energy impact on mechanical behavior of glass fiber-reinforced PUF. After the free-falling type repetitive impact test, a series of compressive tests were performed to investigate the effect of impact conditions on the compressive performance. As a result, the critical impact energy causing degradation of the impact and compressive performance of the material was 1,092 - 1,228 J/m2. In the impact performance, the peak stress, impact duration, and peak strain decreased by 13.5%, increased by 28.5%, and increased by 35.2%, respectively, after 80 repetitions of a 1,500 J/m2 impact. Moreover, under the same impact condition, the elastic modulus of the material decreased by 44.5% compared to that of the intact specimen.

中文翻译：

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玻璃纤维增​​强聚氨酯泡沫在重复低能冲击下的力学性能退化

摘要 聚氨酯泡沫（PUF）由于其封闭的多孔固体结构而具有优良的隔热性能。此外，这种微结构特性提供了出色的冲击吸收性能。由于这些优点，PUF 被广泛应用于交通运输应用中。从在实际应用中的使用来看，有必要对结构进行重复低能量冲击后的残余强度进行评估。因此，在本研究中，我们研究了重复低能量冲击对玻璃纤维增​​强 PUF 机械性能的影响。自由落体式重复冲击试验后，进行一系列压缩试验，研究冲击条件对压缩性能的影响。因此，导致材料冲击和压缩性能下降的临界冲击能量为 1,092 - 1,228 J/m2。在冲击性能上，1500J/m2冲击80次后，峰值应力、冲击持续时间和峰值应变分别下降13.5%、28.5%和35.2%。此外，在相同的冲击条件下，材料的弹性模量与完整试样相比降低了44.5%。