标题： 使用多方向剪切揭示软玻璃材料中的无序诱导应力-流动不对齐现象 显示英文标题

标题： Disorder-induced stress-flow misalignment in soft glassy materials revealed using multi-directional shear

摘要： 控制软玻璃材料的力学响应，如乳液、泡沫和胶体悬浮液，在许多工业过程中至关重要。 尽管它们的稳态流动行为已被较好地理解，但在如泵送或混合等操作中遇到的复杂流动历史对其响应仍知之甚少。 我们使用一种定制的多轴剪切装置，能够任意改变流动方向，研究剪切历史如何影响一种模型软玻璃体系的力学行为。 我们发现了一种与施加剪切方向正交的瞬态剪切响应，以及一个各向异性的屈服表面。 这些效应表明，先前变形留下的内部应力各向异性分布是其根本原因。 为了合理解释这种行为，我们使用了一个介观弹性塑性模型，证明局部机械无序决定了宏观应力-流动不对齐的出现。 我们的研究结果提供了一种新的实验方法来探测软玻璃材料中局部屈服应力的分布。 显示英文摘要

摘要： Controlling the mechanical response of soft glassy materials, such as emulsions, foams, and colloidal suspensions, is key for many industrial processes. While their steady-state flow behavior is reasonably well understood, their response to complex flow histories, as encountered in operations like pumping or mixing, remains poorly known. Using a custom multi-axis shear apparatus that enables arbitrary changes in flow direction, we investigate how shear history influences the mechanical behavior of a model soft glassy system. We uncover a transient shear response orthogonal to the applied shear direction, together with an anisotropic yield surface. These effects point to an underlying anisotropic distribution of internal stresses imprinted by previous deformation. To rationalize this behavior, we use a mesoscopic elasto-plastic model, demonstrating that local mechanical disorder governs the emergence of macroscopic stress-flow misalignment. Our findings offer a new route to experimentally probe the distribution of local yield stresses in soft glassy materials.