# Structural identifiability of parameters of Anand material model

## TL;DR

This paper introduces a method to determine which parameters in the Anand material model can be uniquely identified from tensile test data.

## Contribution

The novel approach combines local and global analysis to reduce parameters and validate identifiability in non-linear models.

## Key findings

- A two-step procedure identifies and validates independent parameters in the Anand model.
- Reduced parameter sets yield unique values in tensile tests with high probability.
- The method uses finite element simulations and numerical substitution for validation.

## Abstract

This article explores the structural identifiability of parameters within non-linear physical models, focussing specifically on the Anand material model. The proposed procedure is structured in two key steps: first, a local analysis identifies the most suitable parameters for testing. Subsequently, these selected parameters, along with their admissible value intervals, are evaluated for global structural dependence. Our innovative numerical approach systematically reduces the parameter count by substituting selected parameters with frozen values (constants). The study employs simulations of the finite element method of a simplified tensile test, utilising the Anand material model. The independent parameters identified through this method are then validated against a tensile test dataset. The validation results indicate a high probability that the use of a reduced parameter set yields unique values for the Anand model parameters in the tensile tests, underscoring the efficacy of our approach.