It is commonly accepted that shear waves do not propagate in a liquid medium. The shear wave energy is supposed to dissipate nearly instantaneously. This statement originates from the difficulty to access “static” shear stress in macroscopic liquids. In this paper, we take a different approach. We focus on the stability of the thermal equilibrium while the liquid (glycerol) is submitted to a sudden shear strain at sub-millimeter scale. The thermal response of the deformed liquid is unveiled. The liquid exhibits simultaneous and opposite bands up to about +0.04 to −0.04 °C temperature variation, while keeping the global thermal balance unchanged. The sudden thermal changes and the long thermal relaxation highlight the ability of the liquid to convert the step strain energy in non-uniform thermodynamic states. The thermal effects depend nearly linearly on the amplitude of the deformation supporting the hypothesis of a shear wave propagation (elastic correlations) extending up to several hundreds micrometers. This new physical effect can be explained in terms of the underlying phonon physics of confined liquids, which unveils a hidden solid-like response with many similarities to glassy systems.

中文翻译：

---

机械变形对液态甘油产生意想不到的热弹性效应

通常认为剪切波不在液体介质中传播。剪切波能量应该几乎瞬间消散。这种说法源于难以获得宏观液体中的“静态”剪切应力。在本文中，我们采用了不同的方法。我们关注热平衡的稳定性，而液体（甘油）在亚毫米级受到突然的剪切应变。变形液体的热响应被揭开。液体表现出同时和相反的带，高达约 +0.04 至 -0.04 °C 的温度变化，同时保持全球热平衡不变。突然的热变化和长时间的热弛豫突出了液体在非均匀热力学状态下转换阶跃应变能的能力。热效应几乎线性取决于变形的幅度，支持延伸至数百微米的剪切波传播（弹性相关性）的假设。这种新的物理效应可以用受限液体的潜在声子物理学来解释，它揭示了一种隐藏的类固体响应，与玻璃系统有许多相似之处。