热老化对聚苯乙烯缓冲材料振动传递特性的影响

Effects of Thermal Aging on Vibration Transmissibility of Expanded Polystyrene

通过正弦扫频振动实验及测试,研究了热老化后聚苯乙烯(EPS)缓冲材料振动传递特性的影响因素及变化规律。结果显示,随着热老化时间延长,EPS材料的阻尼比减小,振动传递率的峰值增加,表明热老化使EPS材料的吸振性能降低;在相同热老化时间条件下,随着载荷的增加,EPS材料的振动传递率增大,且载荷越大其振动传递率增大越快,同时振动系统固有频率呈减小趋势,表明载荷越大EPS缓冲材料传递的响应加速度越大;随着密度的增加,EPS材料的固有频率增大,振动传递率的最大值呈增大趋势,表明EPS材料密度较小时,其柔韧性较好,振动传递率较低,具有较强的隔振性能。

Effects of thermal aging on the vibration transfer characteristics of expanded polystyrene （EPS） cushion material are studied. The purpose is to provide reference for the cushioning packaging design, and to ensure the protection in current process. The accelerated thermal aging conditions are simulated by the frequency sweep experiments to explore the change regularities of vibration transmissibility with the aging time. The resuhs show that the vibration transmissibility was affected by many factors. Above all, the expanded polystyrene damping ratio rose as increasing the aging time and also the peak values of vibration transmissibility increased. It was found that the peak values of vibration transmissibility increased by 42.66% while load 5.0 kg and 21.96% while 2.5 kg by aging at 240h. Moreover, the transmissibility-frequency curve shift to the upper left with the load rising, and the transmissibility-frequency curve shift to the upper right as increasing the expanded polystyrene density. With due consideration of the analysis above, we may draw a conclusion that it＇s necessary to fully consider many factors such as the load, material density and thermal aging time, when choosing vibration-proof packaging materials.