Cutout Geometry Research Articles

Optimum design of laminated composite plates with cutouts undergoing large amplitude oscillations

The present investigation concerns minimum weight design of composite plates in the presence of cutouts undergoing large amplitude oscillations. The Ritz finite element model using a nine-noded C0 continuity, isoparametric element along with a higher order displacement theory which accounts for parabolic variation of transverse shear stresses is used to predict the dynamic behavior. The optimal value is found by using a Genetic Algorithm with tournament selection. Results have been obtained for various cutout geometries like square, rectangular, circular and elliptical in the large amplitude range.

Stability characteristics of composite panels with various cutout geometries

The influence of cutout diameter and shape upon the buckling stability of square CFRP panels is investigated. The study undertaken uses the ANSYS finite element code. Eigenvalue buckling and the postbuckling characteristics of the panels are established. The finite element results are compared with results from physical testing and show good agreement. Results for square panels with fully fixed edge conditions with square, circular and elliptical cutouts under biaxial loading are presented. The results are shown for 2.1 mm thick quasi-isotropic (0/90/ ± 45) 2s 300 mm square panels with cutouts ranging from 30 to 240 mm diameter.

Optimization for buckling resistance of fiber-composite laminate shells with and without cutouts

A sequential linear programming method with a simple move-limit strategy is used to investigate the following three important buckling optimization problems of composite shells: (1) optimization of fiber orientations for maximizing buckling resistance of composite shells without cutouts; (2) optimization of fiber orientations for maximizing buckling resistance of composite shells with circular cutouts; and (3) optimization of cutout geometry for maximizing buckling resistance of a composite shell. From the results of optimization study, it has been shown that, given a structural geometry, loading condition and material system, the buckling resistance of a cylindrical composite shell is strongly influenced by fiber orientations, end conditions, the presence of cutout and the geometry of cutout.