Citation

Gaur P, Verma K, Chawla A, Mukherjee S, Jain M, Mayer C, Chitteti RK, Ghosh P, Malhotra R, Lalvani S. Int. J. Crashworthiness 2020; 25(3): 284-298.

Copyright

(Copyright © 2020, Informa - Taylor and Francis Group)

DOI

10.1080/13588265.2019.1583423

PMID

unavailable

Abstract

Diaphragmatic rupture is the tear of the diaphragm muscle result from blunt or penetrating trauma and occurs in about 5% of cases of severe blunt trauma. Both finite element (FE) modelling and experimental testing have enhanced our understanding of the injury mechanisms associated with diaphragmatic rupture. A constitutive model for human diaphragm tissue is developed and implemented via user subroutine (UMAT) in LS Dyna that accounts for the strain rate-dependent effects and bilinear behaviour observed experimentally. To better understand the material properties of the human diaphragm, 16 dynamic tensile tests were conducted at three different strain rates of 65/s, 130/s and 190/s from six whole human diaphragms. The engineering stress-strain relationship obtained from these tests showed a bilinear behaviour and strain rate dependency. A strain rate-dependent bilinear stress-strain model was developed, and its parameters were optimised using a genetic algorithm-based inverse characterization method. The results demonstrate a good correlation between experiments and the model, with an average difference of 2 ± 2.8% (mean ± SD) between the optimised FE and experimental load-time curves. The material parameters found in this study can be used in dynamic simulations using FE models of diaphragm tissues.

Language: en

Keywords

bilinear behaviour; diaphragm tissue; in vivo testing; finite element analysis; Soft tissue modelling; strain rate dependency