As a substructure of cell cytoskeleton, the crosslinked actin filament networks (CAFNs) play a major role in different cell functions, however, the elastic properties and the deformation mechanisms of CAFNs still remain to be understood. In this paper, a novel three-dimensional (3D) finite element (FE) model has been developed to mimic the mechanical properties of actin filament (F-actin) networks crosslinked by filamin A (FLNA). The simulation results indicate that although the Young's modulus of CAFNs varies in different directions for each random model, the statistical mean value is in-plane isotropic. The crosslinking density and the actin filament volume fraction are found to strongly affect the in-plane shear modulus of CAFNs. The simulation results agree well with the relevant experimental results. In addition, an L-shaped cantilever beam model has been developed for dimensional analysis on the shear stiffness of CAFNs and for quantifying the deformation mechanisms. It has been demonstrated that the in-plane shear modulus of CAFNs is mainly dominated by FLNA (i.e., cross-linkers), and that the bending and torsion deformations of FLNA have almost the same contribution to the stiffness of CAFNs. It has also been found that the stiffness of CAFNs is almost insensitive to the variation of the Poisson's ratios of FLNA and actin filament in the range from 0.29 to 0.499.

作为细胞骨架的子结构，交联的肌动蛋白丝网络（CAFNs）在不同的细胞功能中起主要作用，但是，CAFNs的弹性和变形机理仍有待了解。在本文中，一种新型的三维（3D）有限元（FE）模型已被开发出来，以模拟由纤维蛋白A（FLNA）交联的肌动蛋白丝（F-actin）网络的机械性能。仿真结果表明，尽管对于每个随机模型，CAFN的杨氏模量在不同的方向上都会变化，但统计平均值是面内各向同性的。发现交联密度和肌动蛋白丝体积分数强烈影响CAFN的面内剪切模量。仿真结果与相关实验结果吻合良好。此外，建立了一个L形悬臂梁模型，用于对CAFN的剪切刚度进行尺寸分析并量化变形机制。已经证明，CAFN的面内剪切模量主要由FLNA（即交联剂）控制，并且FLNA的弯曲和扭转变形对CAFN的刚度几乎具有相同的贡献。还发现CAFN的刚度对FLNA和肌动蛋白丝的泊松比在0.29至0.499范围内的变化几乎不敏感。FLNA的弯曲和扭转变形对CAFN刚度的贡献几乎相同。还发现CAFN的刚度对FLNA和肌动蛋白丝的泊松比在0.29至0.499范围内的变化几乎不敏感。FLNA的弯曲和扭转变形对CAFN刚度的贡献几乎相同。还已经发现，CAFN的刚度对FLNA和肌动蛋白丝的泊松比的变化在0.29至0.499范围内几乎不敏感。