Determination of hyperelastic properties of viral capsids using finite element calculation and nanoindentation

Abstract

In this paper a calibration procedure for determining the elastic parameters of empty and filled viral capsids is presented. The procedure combines finite element calculations and results from nanoindentation experiments. The experimental data is from indentation on individual viral particles performed with atomic force microscope. Experimental force–indentation curves for the viral capsid are extracted and compared to force–indentation curves obtained from finite element simulations. The nanoindentation response is simulated using three-dimensional finite element analysis, and the simulations are performed using the finite element code Abaqus. Material parameters such as the Young’s modulus, the shear modulus and the bulk modulus are determined by fitting the force–indentation curves to experimental data by the means of the least squares method. Two different viral capsid are considered: the cowpea chlorotic mottle virus and bacteriophage λ. Predictions are made for the pressure distribution inside the capsid.

Keywords

Viral capsids hyperelastic constants finite element analysis

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