STRESS ANALYSIS OF THICK SPHERICAL PRESSURE VESSEL COMPOSED OF TRANSVERSELY ISOTROPIC FUNCTIONALLY GRADED INCOMPRESSIBLE HYPERELASTIC MATERIALS

Abstract

THE PRESENT PAPER DEVELOPS STRESS ANALYSIS OF TRANSVERSELY ISOTROPIC FUNCTIONALLY GRADED HYPERELASTIC THICK SPHERICAL SHELL SUBJECTED TO INTERNAL AND EXTERNAL PRESSURE. HYPERELASTIC BEHAVIOR IS MODELED BY USING REINFORCED NEO-HOOKEAN STRAIN ENERGY FUNCTION WITH VARIABLE MATERIAL PARAMETERS. THE MECHANICAL PROPERTIES AND MATERIAL CONSTANTS OF STRAIN ENERGY FUNCTION ARE GRADED ALONG THE RADIAL DIRECTION BASED ON A POWER LAW FUNCTION. MATERIAL CONSTANT OF STRAIN ENERGY FUNCTION CALCULATED FROM EXPERIMENTAL DATA BY USING LEVENBERGÂMARQUARDT NONLINEAR REGRESSION METHOD. STRESS COMPONENTS AND STRETCHES OF SPHERICAL SHELL HAVE BEEN OBTAINED FOR AXISYMMETRIC RADIAL CONDITION. FOLLOWING THIS, PROFILES OF EXTENSION RATIO, DEFORMED RADIUS OF SPHERE, RADIAL STRESS AND CIRCUMFERENTIAL STRESS ARE PLOTTED AS A FUNCTION OF RADIUS OF SPHERE IN THE UNDEFORMED CONFIGURATION FOR DIFFERENT MATERIAL INHOMOGENEITY PARAMETER(M). THE OBTAINED RESULTS SHOW THAT THE INHOMOGENEITY PROPERTIES OF FGMS STRUCTURE PARAMETER(B/A) HAVE A SIGNIFICANT INFLUENCE ON THE DISPLACEMENT, STRETCH AND STRESSES DISTRIBUTION ALONG THE RADIAL DIRECTION.