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标题：Variations in Geometry, Volume, Mass and Moment of Inertia of Link of a Four Bar Mechanism Made of Neat Resin Under Hygrothermal Environment
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作者：Shailendra Singh ; S. Sanyal
期刊名称：International Journal of Innovative Research in Science, Engineering and Technology
印刷版ISSN：2347-6710
电子版ISSN：2319-8753
出版年度：2016
卷号：5
期号：12
页码：21371
DOI：10.15680/IJIRSET.2016.0512118
出版社：S&S Publications
摘要：of conventionally used metals(steel and aluminium) with higher specific strength and specificstiffness and contains less weight, thus less inertia forces, stresses, deflections, vibrations of links and mechanism.Mechanisms are also very often used in extreme atmospheric conditions with the requirement of high accuracy andprecision especially in aeronautical, aerospace and marine applications. Objective of this work is to investigate andevaluate the variations in volume, mass and moment of inertia of link of a four bar Grashof Type I, Crank-Rockermechanism made of polymer matrix material (neat Resin) under hygrothermal environment. Chamis proposed theempirical equation for estimating the hygrothermal effect on the matrix properties popularly known as Chamisequation is used here to find out various property degradation of matrix(resin) and composite material. Due toabsorption of moisture volume, mass and moment of inertia will enhance thus kinematics and dynamics of mechanismwill alter. It is evident that under hygrothermal environment due to enhancement in mass and moment of inertia morestresses and deflection will be observed. Also angular, geometrical and structural variations are evaluated using,Freudenstein’s equation. It is found that when a four bar mechanism made of neat resin is working in hygrothermalenvironment, due to absorption of moisture, link swells and due to elevated temperature thermal expansion takes place,collective effect is increase in overall dimensions of link.It is found that in hygrothermal environment presence ofmoisture and high temperature affects kinematics and motion characteristic of four bar mechanism, it adversely affectskinematic accuracy and precision of mechanism, thus mechanism will malfunction. So, it is obligatory that effect ofhygrothermal atmosphere should be taken into consideration while analyzing kinematic performance or designing theplanar mechanism for specific objective. This erroneous behaviour of mechanism can be rectified by estimating exactmagnitude of variations under hygrothermal environment and compensating it by accordingly shortening overalldimension of each link i.e. crank, coupler and rocker.
关键词：Freudenstein’s equation; Fickean diffusion; Chamis Equation; Hygrothermal effect; kinematic;variations; polymer matrix material; epoxy resin; specific strength; specific stiffness.