On low velocity impact response of Sandwich composite with jute/epoxy facesheet and cenosphere reinforced functionally graded Core: Experimental and finite element approach

Abstract The assessment of energy absorption behavior has a vital role in determining suitability of lightweight composites for impact protection applications. This study focuses on evaluating the energy absorption characteristics of cenosphere reinforced epoxy syntactic foam core and jute epoxy facesheet sandwich composite subjected to low velocity impact. The syntactic foam is composed of lightweight cenospheres embedded within an epoxy matrix, resulting in a high‐strength and lightweight composite material. Low velocity impact tests were conducted using a drop tower apparatus to simulate realistic impact conditions. The impact force, energy absorption and damage mitigation of the syntactic foam specimens with varied weight percentage of Cenosphere (0%, 10%, 20% and 30%) were measured and analyzed to assess the energy absorption behavior. The gradation revealed that the weight of top layer when compared to bottom layer is 50.49%, 70.23% and 95.74% less in syntactic foam core with 10, 20 and 30 wt% Cenosphere respectively, indicating gradation. The study demonstrates that the addition of Cenosphere up to 20 wt% enhances the energy absorption capacity of the sandwich composites by 59.37%–93.44% compared to sandwich without Cenosphere reinforced core. However, beyond this threshold, a decline in energy absorption is observed when subjected to low‐velocity impact (LVI). Fractography analysis demonstrates that the incorporation of Cenosphere induces a rough fracture surface with deep river‐like topography, indicative of greater energy absorption during impact loading. This substantiates the conclusion that Cenosphere‐reinforced syntactic foams exhibit enhanced impact resistance, making them promising materials for structures subjected to low‐velocity impact events. Highlights Development of functionally graded core sandwich composite for low velocity impact applications. Assessing the performance of developed composites under low velocity impact loading. Determining the optimal weight percentage of cenospshere in functionally graded core. Studying the fractography of developed sandwich composites. Corelation between experimental and finite element studies.