论文标题
非线性弹性介质中的通用应力矫正
Generic Stress Rectification in Nonlinear Elastic Media
论文作者
论文摘要
非线性培养基中的应力传播在细胞生物学中至关重要，其中分子电动机在纤维细胞骨架上施加各向异性偶极子。虽然力偶极子可以是收缩的或膨胀的，但在压缩下弯曲的纤维制成的培养基会使这些应力符合生物学上关键的收缩。然而，缺乏对这种纠正现象的一般理解，这是介质弹性的函数。在这里，我们使用理论连续性弹性来表明，整流实际上是经受各向异性内部应力的非线性材料的一般效果。我们在分析上表明，经受几何非线性的屈曲和组成性线性材料都可以矫正小力，而颗粒状的材料则构成了呈膨胀的晶状材料。此外，我们使用模拟表明这些结果扩展到更大的力。除了纤维网络之外，这些结果还可以阐明局部塑料重排后脆性或颗粒状材料中应力的传播。
Stress propagation in nonlinear media is crucial in cell biology, where molecular motors exert anisotropic force dipoles on the fibrous cytoskeleton. While the force dipoles can be either contractile or expansile, a medium made of fibers which buckle under compression rectifies these stresses towards a biologically crucial contraction. A general understanding of this rectification phenomenon as a function of the medium's elasticity is however lacking. Here we use theoretical continuum elasticity to show that rectification is actually a very general effect in nonlinear materials subjected to anisotropic internal stresses. We analytically show that both bucklable and constitutively linear materials subjected to geometrical nonlinearities rectify small forces towards contraction, while granular-like materials rectify towards expansion. Using simulations, we moreover show that these results extend to larger forces. Beyond fiber networks, these results could shed light on the propagation of stresses in brittle or granular materials following a local plastic rearrangement.
