屈服应力流体中的通用标度和切换熵
Universal scalings and switching entropy in yield-stress fluids
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中文总结 AI 辅助
研究屈服应力流体在大振幅振荡测试下的非线性振荡响应，通过新流动性模型揭示其可恢复弹性能、脆性和应力反转熵相互交织，定义控制屈服突然性的粘塑性参数，为动态屈服应力提供热机械基础。
中文摘要 AI 辅助
屈服应力流体在临界应力阈值下经历奇异的固-液转变。传统上在稳态剪切下研究，而大振幅振荡测试迫使这些材料在停滞和流化状态之间循环转换。我们发现其非线性振荡响应中隐藏的普遍性：在足够低的频率下，其一阶谐波粘弹性模量相对于应变幅度坍塌到主曲线上。这种坍塌反映了一个不变的周期内应力平台，表明材料几乎瞬间重新排列以维持由其弛豫时间的独特时间轨迹控制的恒定应力状态。我们使用从表现出对称性破缺的李雅普诺夫函数导出的新流动性模型捕捉这种现象学。我们的框架揭示了可恢复弹性能、脆性和应力反转期间产生的熵在根本上相互交织，定义了一个控制屈服突然性的单一粘塑性参数，并为动态屈服应力提供了新的热机械基础。
英文摘要
Yield-stress fluids transition from solid-like to liquid-like behavior at a critical stress threshold, governing phenomena from industrial processing to geological flows. While predominantly investigated under steady shear, large-amplitude oscillatory tests force these materials to cyclically navigate between arrested and fluidized states. Here, we discover a hidden universal behavior where the dynamic viscoelastic moduli of yield-stress fluids collapse onto master curves, revealing that these materials rearrange almost instantaneously to maintain a constant intra-cycle stress state. We fully capture this behavior using a novel theoretical framework based on the minimization of a governing function that exhibits symmetry breaking. Our findings reveal that recoverable elastic energy, yielding abruptness, and entropy production during stress inversion are fundamentally intertwined. This connection provides a unified physical picture for the dynamic yield stress, offering a novel thermomechanical foundation to define and predict this threshold across soft matter physics and materials science.
