Property estimation in FGM plates subject to low-velocity impact loading

Abstract

A property estimation sequence is presented for determining local elastic properties of a two-phased, twoconstituent functionally graded material (FGM) plate subject to impact loading. The property estimation sequence combines the use of experimentally determined strain histories, finite element simulations of the experimental impact events, and an analytical model of the impact tests. The experimental, computational, and analytical models are incorporated into a parameter estimation framework, based on optimization theory, to solve for material properties of individual graded layers in the FGM plate specimens. The property estimation sequence was demonstrated using impact tests performed on a titanium-titanium boride (Ti-TiB) FGM plate system. The estimated material properties of the Ti-TiB FGM from the sequence were shown to correlate well with published material properties for the titaniumtitanium boride FGM system. The estimated properties were further input into a finite element model of the impact events and were shown to approximate the experimental strain histories well. This property estimation framework is formulated to apply to virtually any two-phase FGM system and is thus an invaluable tool for research engineers studying the response of FGMs under load.