Application of the thermodynamic state index: Mapping the Unified Mechanics Theory onto the critical phenomena of the 2D Ising model

Current predictive models for material failure rely heavily on empirical curve-fitting with derivations that do not start from first-principles’ physics. This study proposes a physics-informed framework for reliability by validating the Unified Mechanics Theory (UMT) against the exact analytical solution of the 2D Ising Model. The Thermodynamic State Index (TSI), a normalised measure of entropic disorder, was mapped onto the Onsager solution for the Ising lattice.