There have been many attempts to redesign the aerospace composite structures in recent times to further improve their performance and reduce the weight. As part of these efforts, it has been proposed here that lightweight polymeric foam can be used as an embedded insert inside the fiber reinforced composite structure to further reduce its weight. The target application here is composite fan blade of aircraft engine This paper describes the analysis led design (FEA) and experimental efforts to optimize the shape of this embedded foam insert inside the composite structure under both representative static and dynamic loading so that weight reduction is achieved without affecting the structural performance of the aerospace composite structure. Different geometrical parameters like taper of foam tip, blunting level of the foam tip, use of dual or multiple foam inserts, use of continuous ply layer and other parameters like use of softer material like glass near foam tip, thickness of adhesive (which is used to bond foam with carbon composite) are investigated and their effect on the level of shear stress near the foam tip has been observed. The level of shear stress near the foam insert tip is found to be the major indicator of the possible crack initiation near tip. This study helped optimize the shape of the foam insert inside the composite structure to avoid the initiation of cracks, which is validated by manufacturing the lab level carbon fiber epoxy composite specimens with optimized foam insert geometry and testing them under representative staggered four point bend boundary conditions.