Optimum design of cutouts in laminated composite structures

Abstract Cutouts in aircraft structural components such as wing spars and ribs are commonly encountered in practice. While in certain cases these cutouts are provided to facilitate fuel flow, to pass hydraulic or electrical lines, etc., in other cases they are the means of lightening the structure. For a given elliptical cutout area, loading and laminate construction, optimum design of the cutout is attempted, based on linear analysis. The design involves the selection of aspect ratio and orientation of the ellipse such that the value of the maximum failure criterion around the circumference of the hole is a minimum. The effect of the hole on the critical buckling load is also studied.