# Functionally graded material

Though there are several methods available for manufacturing FGMs, additive based metal deposition by laser, electron beam, plasma etc.

Actually, the concept of FGMs was originated in Japan in during a space project, in the form of proposed thermal barrier material capable of withstanding high-temperature gradients. Numerical results show that the sequence of the natural mode may be altered, and the two natural frequencies may be close to each other because the fiber distribution may change the distributed stiffness and mass of the plate.

## Functionally graded materials an overview of stability buckling and free vibration analysis

This paper presents evolution, current status and challenges of functionally gradient materials FGMs. Applications[ edit ] There are many areas of application for FGM. The most commonly utilized distributions are summarized in what follows. Any further distribution of this work must maintain attribution to the author s and the title of the work, journal citation and DOI. They are formed of two or more constituent phases with a continuously variable composition producing properties that change spatially within a structure. Figure 1. The term forms a part of a descriptive taxonomy of terms relating directly to various particulars relating to the additive CAD - CAM manufacturing processes, originally established as a part of the research conducted by architect Thomas Modeen into the application of the aforementioned techniques in the context of architecture. It can be formed by varying chemical composition, microstructure or design attributes from one end to other as per requirement.

The aircraft and aerospace industry and the computer circuit industry are very interested in the possibility of materials that can withstand very high thermal gradients. Introduction Functionally graded materials FGMs are new generation of advanced composites that have gained interest in several engineering applications such as spacecraft heat shields, high-performance structural elements, and critical engine components [ 12 ].

The transition between the two materials can usually be approximated by means of a power series. In all, the given mathematical models can be regarded as useful design tools, which may save designers from having to choose the values of some of their variables arbitrarily.

## Difference between composite and functionally graded material

It can be formed by varying chemical composition, microstructure or design attributes from one end to other as per requirement. An inverse problem was solved to find the stiffness and mass distributions so that the chosen polynomial serves as an exact mode shape. This study first demonstrates the flutter analysis of composite laminates with variable fiber spacing. They are formed of two or more constituent phases with a continuously variable composition producing properties that change spatially within a structure. This volume fraction is based on the mixture of metal and ceramic and is an indicator of the material composition volumetric wise at any given location in the thickness. Qian and Batra [ 9 ] considered frequency optimization of a cantilevered plate with variable volume fraction according to simple power laws. If it is for thermal, or corrosive resistance or malleability and toughness both strengths of the material may be used to avoid corrosion, fatigue, fracture and stress corrosion cracking. Another work presented an analytical approach for designing efficient patterns of FGM bars having maximized frequencies while maintaining the total mass at a constant value [ 10 ]. This produced a piecewise grading of the material and thickness in the radial direction. Various manufacturing processes of different types of FGMs are also presented. Initially, the variation of material properties was introduced by means of rows or columns of homogeneous elements, leading to a discontinuous step-type variation in the mechanical properties.

Various manufacturing processes of different types of FGMs are also presented. Considering dynamic aeroelasticity of FGM structures, Shin-Yao [ 15 ] investigated the effect of variable fiber spacing on the supersonic flutter of composite laminates using the finite element method and quasi-steady aerodynamic theory.

Case studies include frequency optimization of thin-walled box beams, optimal design of drive shafts against torsional buckling and whirling, and aeroelastic optimization of subsonic aircraft wings.

The volume fraction of the constituent materials was defined by simple power laws, and closed form solutions using Fourier series were given for the case of simply supported plates.

The formulation of the location-dependent stiffness and mass matrices due to nonhomogeneous material properties was derived.

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