This paper presents an investigation into the mechanical properties and structural analysis of composites fabricated using glass microballoons, crumb rubber filler, and high-density polyethylene (HDPE). The aim of this study is to explore the synergistic effects of these components on the tensile behavior of the resulting composite material. The composite samples were prepared by incorporating varying proportions of glass microballoons and crumb rubber filler into the HDPE matrix. Tensile tests were conducted on the composite samples to evaluate their mechanical properties, including stress-strain behavior, yield strength, ultimate tensile strength, and elongation at break. Additionally, finite element analysis (FEA) was performed to simulate and visualize the stress distribution and deformation patterns within the composite material. The results revealed that the addition of glass microballoons enhanced the stiffness and strength of the composite, leading to improved mechanical properties. Furthermore, the incorporation of crumb rubber filler contributed to increased flexibility, impact resistance, and vibration damping capabilities of the composite. The experimental findings were found to be in good agreement with the FEA results, validating the accuracy and reliability of the simulation.