Data for: "Isotropic hyperelasticity in principal stretches: Fortran programs and subroutines"

This dataset contains Fortran programs and subroutines for a robust and accurate numerical implementation of hyperelastic constitutive models defined in terms of principal stretches for use in the Finite Element Method. It uses explicit computation of principal stretches and associated principal directions. Fortran programs enable computation of the stress and elasticity tensors in material and spatial configurations. UMAT subroutines are also contained, which allow for user-defined materials to be implemented within the commercial Finite Element Method software Abaqus. Templates are provided such that the user may easily implement a constitutive model, requiring only the derivatives of the strain energy function with respect to the isochoric principal stretches.

The Fortran programs were created and tested using Abaqus/Standard v2016, Microsoft Visual Studio 2010 and Intel Parallel Studio XE 2013.

Additional numerical results are provided in an Excel file (created using Excel 2013). These are the results of a numerical study to find an approximate optimal tolerance value for the proposed algorithm used to avoid numerical errors when principal stretches are numerically similar or equal.