Anti‐Ballistic Penetration Characteristics of High‐Performance Composite Sandwich Wall Panels

ABSTRACT To achieve both lightweight construction and high ballistic protection capability in prefabricated container houses, this paper proposes a High‐Performance Composite Sandwich Wall Panel (HCSWP), which consists of a high‐performance fiber/steel composite bulletproof layer and a buffer energy‐absorbing layer. The penetration process, failure modes, and penetration resistance properties of the HCSWP subjected to 7.62 × 54 mm standard bullet were investigated through the standard ballistic test and CT scanning techniques. The test results revealed that the proposed HCSWP had excellent ballistic resistance. In particular, the S2‐U10 specimen successfully intercepted 7.62 mm bullets at velocities of 831 m/s and 814 m/s, and the minimum weight of the test specimens is only 51 kg/m ² . Further, a finite element model of the HCSWP was established and verified by the experimental results. The numerical results indicated that the kinetic energy of the bullet is dissipated by tensile fracture of fiber, interlaminar delamination within glass fibers and ultra‐high molecular weight polyethylene (UHMWPE) fibers themselves, as well as interfacial delamination between different materials, and the energy absorption provided by material elastic rebound. The UHMWPE laminates play a key role in enhancing the anti‐penetration performance of the HCSWP; due to its high strength and high modulus, it can dissipate a significant amount of bullet kinetic energy through tensile failure and delamination failure. By optimizing the thickness ratio between glass fiber reinforced polymer (GFRP) and UHMWPE layers, the bulletproof layer of the HCSWP adopts a combination of two 8 mm thick UHMWPE layers and four 6 mm thick GFRP layers, achieving an optimal balance between protection, weight, and cost.