论文标题
在玻璃中的机械β松弛及其与高温脉冲振动中双峰现象的关系
On the mechanical beta relaxation in glass and its relation to the double-peak phenomenon in impulse excited vibration at high temperatures
论文作者
论文摘要
在冲动激发振动的实验中，建立了粘弹性模型，以揭示玻璃的α-β弛豫与双峰现象之间的关系。在建模中，采用了势能景观（PEL）图片的正常模式分析（NMA）来描述玻璃材料中的机械α和β弛豫。该模型表明，当β弛豫峰的频率接近样品的固有频率时，玻璃梁的自由振动会导致玻璃梁的自由振动产生明显的双峰现象。理论预测通过中跨冲动激发的氟硅酸盐玻璃束的声谱得到了验证。此外，实验结果表明，氟化玻璃S-FSL5中β弛豫频率的温度依赖性负依赖性，可以根据液体样区域的氧化氧化物网络斑块的物理图片来解释。
A viscoelastic model is established to reveal the relation between alpha-beta relaxation of glass and the double-peak phenomenon in the experiments of impulse excited vibration. In the modelling, the normal mode analysis (NMA) of potential energy landscape (PEL) picture is employed to describe mechanical alpha and beta relaxations in a glassy material. The model indicates that a small beta relaxation can lead to an apparent double-peak phenomenon resulted from the free vibration of a glass beam when the frequency of beta relaxation peak is close to the natural frequency of specimen. The theoretical prediction is validated by the acoustic spectrum of a fluorosilicate glass beam excited by a mid-span impulse. Furthermore, the experimental results indicate a negative temperature-dependence of the frequency of beta relaxation in the fluorosilicate glass S-FSL5 which can be explained based on the physical picture of fragmented oxide-network patches in liquid-like regions.
