Gibbons Melissa M, Perotti Luigi E, Klug William S
Department of Mechanical and Aerospace Engineering, UCLA, 420 Westwood Plaza, Los Angeles, CA, 90095, USA.
Methods Mol Biol. 2015;1252:139-88. doi: 10.1007/978-1-4939-2131-7_12.
Viral capsids undergo significant mechanical deformations during their assembly, maturation, and infective life-span. In order to characterize the mechanics of viral capsids, their response to applied external forces is analyzed in several experimental studies using, for instance, Atomic Force Microscope (AFM) indentation experiments. In recent years, a broader approach to study the mechanics of viral capsids has leveraged the theoretical tools proper of continuum mechanics. Even though the theory of continuum elasticity is most commonly used to study deformable bodies at larger macroscopic length scales, it has been shown that this very rich theoretical field can still offer useful insights into the mechanics of viral structures at the nanometer scale. Here we show the construction of viral capsid continuum mechanics models starting from different forms of experimental data. We will discuss the kinematics assumptions, the issue of the reference configuration, the material constitutive laws, and the numerical discretization necessary to construct a complete Finite Element capsid mechanical model. Some examples in the second part of the chapter will show the predictive capabilities of the constructed models and underline useful practical aspects related to efficiency and accuracy. We conclude each example by collecting several key findings discovered by simulating AFM indentation experiments using the constructed numerical models.
病毒衣壳在其组装、成熟和感染生命周期中会经历显著的机械变形。为了表征病毒衣壳的力学特性，在一些实验研究中，例如使用原子力显微镜（AFM）压痕实验，分析了它们对外部施加力的响应。近年来，一种更广泛的研究病毒衣壳力学的方法利用了连续介质力学的理论工具。尽管连续介质弹性理论最常用于在较大的宏观长度尺度上研究可变形体，但已经表明，这个非常丰富的理论领域仍然可以为纳米尺度的病毒结构力学提供有用的见解。在这里，我们展示了从不同形式的实验数据构建病毒衣壳连续介质力学模型的过程。我们将讨论运动学假设、参考构型问题、材料本构定律以及构建完整的有限元衣壳力学模型所需的数值离散化。本章第二部分的一些例子将展示所构建模型的预测能力，并强调与效率和准确性相关的有用实际方面。我们通过收集使用所构建的数值模型模拟AFM压痕实验发现的几个关键发现来结束每个例子。
