An accurate and fast approach for determining materials stress-strain curves by nanoindentation and its FEM-based simulation

摘要

An accurate procedure, implemented by the "SSCUBONI" ("Stress-Stain CUrves Based On Nanoindentation") algorithm for the determination of coatings' and other materials' stress-strain curves, was recently introduced. This algorithm performs a finite elements method (FEM)-based continuous simulation of the nanoindentation, taking into account the effects of the indenter tip defects and elastic deformation. The accuracy of this algorithm has been proved to be very high; however, the algorithm is time consuming and demands experienced users. In this paper, the fast and fully automated software "FANOS" (Fast Approach of stress-strain curves based on naNOindentationS) is introduced, thus enabling the evaluation of measured nanoindentation load versus displacement curves to further calculate stress-strain data of elastic-plastic specimens. Various relationships obtained by the "SSCUBONI" algorithm, capturing the effect of the indentation load and depth on the developed stresses and strains are incorporated into the new algorithm. Following these methodological steps, the elasticity modulus, the yield strength and the tangent moduli of plasticity of various materials can be determined accurately and quickly. Taking as a basis the introduced "FANOS" algorithm, a relevant software was developed, without requiring any dedicated software environment.