NOVEL LAYERWISE SHEAR CORRECTION FACTORS FOR ZIGZAG THEORIES OF CIRCULAR SANDWICH PLATES WITH FUNCTIONALLY GRADED LAYERS

Abstract

THE AVAILABLE SHEAR CORRECTION FACTORS HAVE MAINLY BEEN PROPOSED FOR SINGLE-LAYER RECTANGULAR PLATES WITH ZERO SHEAR TRACTIONS AND ISOTROPIC HOMOGENOUS MATERIALS. THE PRESENT ANALYTICAL SHEAR FACTORS ARE ESPECIALLY SUITABLE FOR THE FIRST-ORDER ZIGZAG OR LAYERWISE THEORIES OF CIRCULAR SANDWICH PLATES WITH FUNCTIONALLY GRADED CORES/FACE SHEETS AND SIMULTANEOUS NORMAL AND SHEAR TRACTIONS. ALTHOUGH THE PRESENT LAYERWISE CORRECTION FACTORS ARE GENERAL, THEY ARE EVALUATED FOR THE MODAL ANALYSES WHERE EFFECTS OF THE SHEAR CORRECTION ARE MORE REMARKABLE THAN THOSE OF THE STRESS ANALYSES. IT IS THE FIRST TIME THAT THE CONCEPT OF THE LOCAL SHEAR CORRECTION FACTOR IS INTRODUCED. TO PRESENT MORE ACCURATE RESULTS, THE MORI-TANAKA MICROMECHANICAL-BASED MATERIAL PROPERTIES MODEL IS USED INSTEAD OF THE TRADITIONAL RULE OF MIXTURES. THE GOVERNING EQUA-TIONS ARE SOLVED USING THE ANALYTICAL TAYLOR TRANSFORM METHOD. COMPARISONS MADE AMONG RESULTS ASSOCIATED WITH THE KNOWN SHEAR CORRECTION FACTORS, PRESENT RESULTS, AND RESULTS OF THE THREE-DIMENSIONAL THEORY OF ELASTICITY REVEAL THAT SIGNIFICANT ENHANCE-MENTS MAY OCCUR THROUGH USING THE PROPOSED ANALYTICAL SHEAR CORRECTION FACTORS.