ASSESSMENT OF INTERLAMINAR STRESS COMPONENTS IN LAMINATED COMPOSITES MANUFACTURED BY PLY-DROP TECHNIQUE

Tapered composites have found applications in a wide spectrum of areas, mainly owing to its weight savings and'tailoring' options possible for its mechanical properties. This calls for a thorough analysis required to predict the response of the tapered laminates, which are formed by dropping some part of the plies at certain fixed locations. The present study is a linear elastic finite element study of a three-dimensional rectangular laminate made of an orthotropic material T300/5208 graphite-epoxy unidirectional tape, and its response when exposed to an axial or extensional load. Delamination is the major source of failure in laminates with ply drop-offs. Therefore, only the major interlaminar stresses affects the behavior of the laminate and all other stresses which do not directly contribute to the interlaminar failure can be neglected. Based on the above observations, a two-dimensional model (2D) of a particular symmetric ply-configuration of the body, subjected to a tensile load is analyzed on a commercial package, ANSYS 16.2 and the results obtained are compared against established results. It is shown that stress concentration is high near the drop-off and becomes comparatively insignificant at further locations.This analysis can provide insight into the parameters affecting the strength and endurance of the structure to external load conditions and obtaining an ideal configuration extending scope of maximum performance.