International Research Journal of Engineering and Technology (IRJET)
e-ISSN: 2395 -0056
Volume: 04 Issue: 01 | Jan -2017
p-ISSN: 2395-0072
www.irjet.net
Static and Transient Vibrational Analysis of Functionally Graded Material Anil Kumar1, Dr. D K Maiti2 1Postgraduate, 2 Professor,
Dept. of Aerospace Engineering, Indian Institute of Technology-Kharagpur, West Bengal, India Dept. of Aerospace Engineering, Indian Institute of Technology-Kharagpur, West Bengal, India
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Abstract - In the present work, Static and Transient
may be present due to difference in coefficients of thermal expansion of the fibre and the matrix, etc.
vibrational analysis of Functionally Graded Materials under mechanical load are investigated in thermal environment. Functionally Graded Material (FGM) is a class of composite material, usually mixture of Ceramic and Metals. The material properties are assumed to vary continuously through their thickness according to a Power-law distribution. Finite element method is used to study the Static, Free Vibration and Transient vibrational analyses. The numerical results on the transverse deflection in a moderately thick functionally graded plate under uniformly distributed load for various boundary conditions are discussed. The effects of Power-law index for Al/ZrO2 Functionally Graded plates on deflection are commented. Different geometrical shapes of Al/ZrO 2 Functionally Graded shells and panels are included to study the free vibration; the effect of volume fractions on their frequency characteristics is discussed. Isotropic plate and Si3N4/SUS304 Functionally Graded square plates are included in the study of transient vibration analysis in thermal environment and the effect of Power-law index is discussed in detail.
A new class of materials known as Functionally Graded Materials (FGMs) was proposed in 1980's which overcome the limitations that were found in traditional composite. FGMs are microscopically inhomogeneous composites usually made from a mixture of metals and ceramics. By gradually varying the volume fraction of constituent materials, their material properties exhibit a smooth and continuous change from one surface to another, thus eliminating interface problems and mitigating thermal stress concentrations, which are very common in traditional composites. For various applications, the FGM approach has been explored to mitigate some of the major problems associated with development of a sharp interface at the join of two dissimilar materials. FGMs are usually more superior to the conventional laminated materials because of no discernable internal interfaces or boundaries, and no internal stress peaks are caused when external loads are applied and thus failure from interfacial debonding or from stress concentration can be avoided.
Key Words: Functionally Graded Material, FGM, Transient Vibrational Analysis, FGM Plates, FGM Shells and Panels, Al/ZrO2 FGM, Si3N4/SUS304 FGM
The continuous change in the microstructure of Functionally Graded Material (FGM) distinguishes them from the fibrereinforced laminated composite materials. An FGM consist of ceramic on the outside surface exposed to high temperature provides thermal resistance due to its low thermal conductivity while the metallic constituent provides toughness of the plate, that provides thermal corrosion protection and load carrying capability. The FGM are ideal for applications involving severe thermal gradients, ranging from thermal structures in advanced aircraft and aerospace engines to computer circuit boards.
1. INTRODUCTION Strength of the metal is reduced after it has been in high temperature environment for a period of time; beside metal has a low melting point. Other side, ceramic materials have excellent characteristics in strength and heat-resistance. Due to their low toughness their applications are usually limited. Composite materials have been widely used in aerospace structural components, automobile industries and many other industrial applications, due to their high specific strength, high specific stiffness, anti-corrosion ability, workability, low density, superior performance reliability, ease in fabrication of complex shapes and several other attributes. But the composite materials have some limitations such as the weakness of interfaces between layers that to de-lamination, extreme thermal loads that may lead to de-bonding between matrix and fibre due to mismatch of mechanical properties, residual stresses that
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Fig -1: Conventional heat resistant material and FGM
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