Calibration of Drucker-Prager plasticity in prosthetic materials: From experimental characterization to reverse-engineering finite element analysis.

Abstract

Accurate simulation of prosthetic materials requires constitutive models that capture pressure sensitivity and tension-compression asymmetry beyond linear elasticity. This study presents a reverse-engineering workflow to calibrate a Drucker-Prager based constitutive model in LS-DYNA using the semi-analytical model for polymers MAT 187L SAMP Light for a resin composite (Brilliant Crios) and a polymer-infiltrated ceramic network (Vita Enamic). Unconfined uniaxial compression, three-point bending, and Brazilian disc tests provide elastic constants and strength measures that serve as inputs and calibration targets. An analytical initialization maps experimentally determined yield stresses to the linear Drucker-Prager yield surface, supplying reliable starting parameters for finite element reverse-engineering optimization. The calibrated model captures the material response in the calibration tests (three-point bending and Brazilian disc) within the pre-peak regime, and an out-of-sample punch-through test confirms the transferability of the parameters without additional tuning. Compared to von Mises characterization approaches, the pressure-dependent characterization was achieved with only one additional test configuration, shifting effort from experiments to numerical computation optimization. Within these limits, the results support pressure-dependent, asymmetric plasticity as a practical basis for predictive finite element analysis of dental restoratives, while highlighting that explicit damage and strain-rate effects should be incorporated in future work to model softening and failure consistently.