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.

Numerical Modeling of an FG Plate Behavior Impacted at Low Velocity in a Temperature Field

“…The contact force is deduced from the Eq. (6). Figures 1-3 show the variation of the contact force, indentation and indentation speed according to the time for a volume fraction index of n = 0 at different temperatures.…”

“…It uses energy-balance models to assess the strength and the contact time. Many authors are interested in the study of the behavior of structures subjected to impact loads [2][3][4][5][6]. Larson et al [5,6] developed a combined analytical and experimental methods to study the behavior of a Functionnally graded circular plate under different boundary conditions.…”

Preliminary Investigations of the Low-Velocity Impact Response of a Smart Trimorph Plate for Active Damage Mitigation

“…Since the trimorph plate is made up three different isotropic materials laminated together, effective properties are needed and cannot be obtained from available material properties data. An approximate analytical solution to the problem is the 'strength of materials' approach which has been applied in studying the low-velocity impact response of sandwich laminates [19] and functionally graded laminates [20], and verified experimentally for impact analysis [21]. The strength of materials approach is suitable for use under plane stress conditions, quasi-static loading and when the effect of the in-plane material properties of the target on the transverse deformation can be neglected [19].…”

“…In this section, a parametric study is carried out to demonstrate that the flexibility of a trimorph plate, which can be altered using active pre-stressing induced by piezo-actuation, could be exploited to mitigate impact damage effects. To achieve this, a parameter, , used to alter the effective transverse stiffness of the trimorph plate without changing the dimensions or material properties of the plate (as would be expected during active pre-stressing induced by piezoactuation) is introduced into the transverse vibration model as shown in equation (21). The parameter, , represents the percentage change in the effective transverse stiffness of the plate.…”