A COMPUTATIONAL STRATEGY TO EXAMINE THE PROFILE EFFECTS OF MICROPRISM REGIONS ON THE OVERALL ANISOTROPY OF HUMAN ENAMELS

In this study, our attention is mainly on elaborating a computational strategy to effectively predict the influence of prism profiles on the overall anisotropic property of human enamels (HEs). At first, two distinct schemes are developed separately with the aid of the polynomial fitting technique and the general power functions to mathematically describe the practical irregular and simplified regular profiles of enamel prisms. Hereafter, two parametric piecewise formulas, which facilitate the definition of anisotropic material properties of finite elements at different locations and make the numerical simulation of HE microstructures consisting of irregularly shaped prisms feasible, are presented to describe the orientation of hydroxyapatite (HAP) crystallites embedded in microprisms. The effective anisotropic moduli over a representative unit cell (RUC) under the periodic displacement constraint is concisely introduced according to the micromechanics, and a computational strategy is established to calculate these moduli numerically. Finally, the evaluations in the open literature are employed to demonstrate the validity of the elaborated computational strategy, and more investigations are conducted and yield the conclusions such that the material property of the inter-prism regions as well as the prism shapes plays a crucial role in determining the overall anisotropy of HEs.