基于分数阶微分流变模型的非晶合金黏弹性行为及流变本构参数研究

发布时间：2018-04-14 06:00

本文选题：非晶合金 + 分数阶微分流变模型　；参考：《物理学报》2016年04期

【摘要】：近年来,基于非晶合金名义弹性区的流变力学行为探索其结构及形变机理是非晶合金领域研究的热点之一.本文根据非晶合金结构不均匀性的特征,提出能够比拟树状分形网络结构的分数阶微分流变模型研究非晶合金的黏弹性行为.通过室温纳米压痕实验,对三种不同泊松比和玻璃化转变温度的非晶合金的黏弹性变形行为进行了研究.实验结果表明:在表观弹性区,非晶合金的变形表现出与加载速率相关的线性黏弹性性质.根据Riemann-Liouville分数阶微积分定义,分别由分数阶微分及整数阶Kelvin模型对实验结果进行了分析.分析结果表明:相对于整数阶流变模型,分数阶微分流变模型能更精细地表征材料的黏弹性变形特征;在流变模型参数中,黏性系数ηA和分数阶次α反映出材料的流变特性和流动趋势,流变参数与玻璃转变温度、泊松比之间具有较好的相关性,上述相关性有助于从微观结构角度理解材料塑性与泊松比的关联.
[Abstract]:In recent years, based on the rheological behavior of the nominal elastic region of amorphous alloys, it is one of the hotspots in the field of amorphous alloys to explore its structure and deformation mechanism.According to the characteristics of structural inhomogeneity of amorphous alloys, a fractional differential rheological model, which can compare dendritic fractal network structure, is proposed to study the viscoelastic behavior of amorphous alloys.The viscoelastic deformation behavior of three kinds of amorphous alloys with different Poisson's ratio and glass transition temperature was studied by nano-indentation at room temperature.The experimental results show that the deformation of amorphous alloys exhibits linear viscoelastic properties related to loading rate in the apparent elastic region.According to the definition of Riemann-Liouville fractional calculus, the experimental results are analyzed by fractional differential model and integer order Kelvin model, respectively.The results show that the fractional differential rheological model can represent the viscoelastic deformation characteristics of the material more accurately than the integral order rheological model, and in the rheological model parameters,Viscosity coefficient 畏 A and fractional order 伪 reflect the rheological characteristics and flow trend of the material. The rheological parameters have a good correlation with glass transition temperature and Poisson's ratio.The above correlation is helpful to understand the relationship between material plasticity and Poisson's ratio from the point of view of microstructure.
【作者单位】：湘潭大学土木工程与力学学院;
【基金】：国家自然科学基金(批准号:51471139,51401176,21376199) 湖南省自然科学基金(批准号:14JJ3078)资助的课题~~
【分类号】：O37

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