XML Template (2013) [19.9.2013–3:34pm] [1–14] //blrnas3/cenpro/ApplicationFiles/Journals/SAGE/3B2/PILJ/Vol00000/130057/APPFile/SG-PILJ130057.3d (PIL) [PREPRINTER stage] Original Article

Determination of elastic and viscoplastic material properties obtained from indentation tests using a combined finite element analysis and optimization approach JJ Kang, AA Becker and W Sun Conventional indentation tests do not provide an accurate estimation of viscoplastic material properties. In this work, a combined finite element analysis and optimization approach is developed for the determination of elastic–plastic and creep material properties using only a single indentation loading–unloading curve based on a two-layer viscoplasticity model. Utilizing the indentation loading–unloading curve obtained from a finite element-simulated experiment with a spherical and a conical indenter, a set of six key material properties (Young’s modulus, yield stress, work hardening exponent and three creep parameters) can be determined. Non-linear optimization algorithms are used with different sets of initial material properties, leading to good agreements with the numerically simulated target loading–unloading curves