VIBRATION ANALYSIS OF CNT REINFORCED FUNCTIONALLY GRADED MATERIAL

Abstract

Functionally Graded Material (FGM) comes under category of advanced materials, where properties of material varies in specified direction. Overall properties of FGM is different from their parent materials. Carbon Nanotubes (CNTs) are strongest material with lesser weight known till now. From this directly structures cannot be developed due to technology limitations. So these properties are utilized by mixing CNTs in different materials. In this work, CNT reinforced FGM is used. Matrix material is aluminum considered as CNT reinforced Al FGM have lots of engineering applications. CNT reinforced FGM nano plate is considered where CNT volume fraction varies linearly 2% to 0% from top to bottom surface. Effect of CNTs on FGM have been evaluated using mechanical, thermo mechanical and mode shape analysis. Deflection results for mechanical and thermo mechanical conditions, mode shapes with their natural frequencies has been compared with Al nano plate without CNTs, CNT reinforced Al composite nano plate. Effect of waviness defect in CNTs with waviness index of 0.02, 0.04, 0.06 and 0.08 on FGM and composite nano plate under mechanical, thermo mechanical conditions and natural frequencies with their mode shapes are also compared with straight CNT reinforced FGM and Composite. It was observed from the analysis that under mechanical, thermo mechanical and free vibration condition, Al nano plate without CNTs is weakest, while CNT reinforced FGM nano plate is slightly weaker then CNT reinforced composite nano plate under mechanical loading, while it is reverse in thermo mechanical loading. Similar pattern was observed for natural frequencies. In CNTs waviness defect study it is found that as initially the waviness introduced, the strength of nano plate increased but strength decreases with increase in waviness further. It was observed through this analysis, that CNT reinforced composite is still better option for good strength mechanical application, but FGM is better option where elevated temperature exists. All these observations will help to design FGM plate for specific applications.