Abstract This work explores the viscoelastic behavior of two types of polymeric foams: an open-cell melamine foam and a closed-cell polyurethane foam. Experimental measurements were carried out on a torsional rheometer to estimate the complex shear modulus as a function of both temperature and frequency. A different and in some cases strong dependence of shear storage and loss moduli upon frequency and temperature was evidenced. The long-term viscoelastic behavior was then identified through the application of the time-temperature superposition principle. A fractional derivative model was properly calibrated to describe the behavior of each foam. This approach enabled two numerical simulations to further investigate the dissipation of mechanical energy. The first simulations explored hysteresis phenomena in cyclic loads in the time domain. The second tests analyzed their vibration damping performances in the low-frequency range. In both cases, only the viscoelasticity of the foam's skeleton was taken into account. The closed-cell polyurethane foam showed a greater ability to dissipate mechanical energy.

中文翻译：

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聚合物泡沫的粘弹性行为：实验和建模

摘要 这项工作探讨了两种类型的聚合物泡沫的粘弹性行为：开孔三聚氰胺泡沫和闭孔聚氨酯泡沫。在扭转流变仪上进行实验测量以估计作为温度和频率的函数的复数剪切模量。证明了剪切存储和损耗模量对频率和温度的不同且在某些情况下的强烈依赖性。然后通过应用时间-温度叠加原理来确定长期粘弹性行为。分数导数模型经过适当校准以描述每种泡沫的行为。这种方法使两个数值模拟能够进一步研究机械能的耗散。第一次模拟探索了时域中循环负载中的滞后现象。第二次测试分析了它们在低频范围内的减振性能。在这两种情况下，只考虑了泡沫骨架的粘弹性。闭孔聚氨酯泡沫表现出更强的机械能消散能力。