NONLINEAR ANALYSIS ON BUCKLING AND POSTBUCKLING OF STIFFENED FGM IMPERFECT CYLINDRICAL SHELLS FILLED INSIDE BY ELASTIC FOUNDATIONS IN THERMAL ENVIRONMENT USING TSDT

Abstract

THE MAIN AIM OF THIS PAPER IS TO INVESTIGATE ANALYTICALLY NONLINEAR BUCKLING AND POST-BUCKLING OF FUNCTIONALLY GRADED STIFFENED CIRCULAR CYLINDRICAL SHELLS FILLED INSIDE BY PASTERNAK TWO-PARAMETER ELASTIC FOUNDATIONS IN THERMAL ENVIRONMENTS AND UNDER AXIAL COMPRESSION LOAD AND EXTERNAL PRESSURE BY ANALYTICAL APPROACH. SHELLS ARE REINFORCED BY CLOSELY SPACED RINGS AND STRINGERS. THE MATERIAL PROPERTIES OF SHELL AND THE STIFFENERS ARE ASSUMED TO BE CONTINUOUSLY GRADED IN THE THICKNESS DIRECTION. USING THE REDDY THIRD ORDER SHEAR DEFORMATION SHELL THEORY, STRESS FUNCTION METHOD AND LEKHNITSKII SMEARED STIFFENERS TECHNIQUE, THE GOVERNING EQUATIONS ARE DERIVED. THE CLOSED FORM TO DETERMINE CRITICAL AXIAL LOAD AND POST-BUCKLING LOADÂDEFLECTION CURVES ARE OBTAINED BY GALERKIN METHOD. THE EFFECTS OF TEMPERATURE, STIFFENER, FOUNDATION, MATERIAL AND DIMENSIONAL PARAMETERS ON THE STABILITY BEHAVIOR OF SHELLS ARE SHOWN. THE ACCURACY OF THE PRESENTED METHOD IS AFFIRMED BY COMPARISONS WITH WHELL-KNOWN RESULTS IN REFERENCES. THE RESULTS SHOWN FOR THICK CYLINDRICAL SHELLS, THE USE OF FSDT FOR DETERMINING THEIR CRITICAL BUCKLING LOAD IS NECESSARY AND MORE SUITABLE.