This paper presents a Galerkin-based meshless method for calculating stress-intensity factors (SIFs) for a stationary crack in two-dimensional functionally graded materials of arbitrary geometry. The method involves an element-free Galerkin method (EFGM), where the material properties are smooth functions of spatial coordinates and two newly developed interaction integrals for mixed-mode fractu...

Characterization of Cu/diamond interface thermal conductance (hc) and an improved understanding of factors affecting it are important, as Cu-diamond composites are increasingly being considered for electronic packaging applications. In this study, ~90 nm thick Cu layer was deposited on synthetic as well as natural diamond substrates. In several specimens, a Ti-interface layer of thickness ≤ 3.5...

This study develops a micromechanical damage model for two-phase functionally graded materials considering the interfacial debonding of particles and pair-wise interactions between particles. Given an applied mechanical loading, in the particle-matrix zones, the interactions from all other particles over the representative volume element are integrated to calculate the homogenized elastic field...

Presented in this paper is a novel additive manufacturing technology for making three-dimensional parts with functionally graded materials (FGMs), called Freeze-form Extrusion Fabrication (FEF). The system development included extruder modeling and control, composition gradient control for a tripleextruder mechanism, and motion code generation for a 3-axis positioning system. The effectiveness ...

Vapor-deposition techniques are emerging as an economical and flexible way of fabricating multiphase materials with spatially varying architectures. The aim of this work is to design architectures that exploit the concept of functional grading. We consider two basic problems; the first is the computation of the response of an infinite plate with a circular hole to a remote symmetric radial load...

The introduction of controlled gradients in plastic properties is known to influence the resistance to damage and cracking at contact surfaces in many tribological applications. In order to assess potentially beneficial effects of plastic property gradients in tribological applications, it is essential first to develop a comprehensive and quantitative understanding of the effects of yield stren...

The spatially distributed microstructures needed to implement many functionally graded material (FGM) designs are difficult to realize affordably with today's materials synthesis/processing technologies. To address this need, a new directed vapor deposition (DVD) technique has been developed and explored as a potential FGM synthesis tool. The technique exploits supersonic helium jets in combina...

This paper presents an overview of both T-Trefftz and F-Trefftz finite element methods (FEM) and its application in various engineering problems. Recent developments on the T-Trefftz finite element formulation of nonlinear problems of minimal surface, F-Trefftz methods for composite, skin tissue, and functionally graded materials are described. Formulations for all cases are derived by means of...

We present the combined efforts of a research network designed to address many challenges in experimental modelling debris flow phenomena. The approach has been use apparatuses different functional arrangement and at scale with identical commonly sourced materials from highly idealised (dry, coarse uniform) complex (well graded, segregating, fluid saturated). Here we briefly some key findings p...

Functionally graded materials (FGM) in the form of layered structure consisting of yttria stabilized zirconia (8 mol% Y2O3) and nickel were fabricated by spark plasma sintering procedure. The relative density, linear shrinkage and Vickers hardness of each layer of graded materials were measured. The microstructure and the composition of these components were studied. The results obtained show t...