The penetration resistance behavior and corresponding size effects of ultra-high molecular weight polyethylene composite laminates

Focusing on the energy absorption characteristics of ultra-high molecular weight polyethylene (UHMWPE) fiber laminated panels, this study conducts ballistic tests and numerical simulations using 6 mm spherical projectiles to impact the UHMWPE laminated panels. The residual velocity characteristics, energy absorption patterns, and failure modes of the UHMWPE laminated panels under steel ball impacts were analyzed. The results show that the residual velocity of the steel ball increases with the increase of the incident velocity. In the velocity range near the ballistic limit velocity, the residual velocity of the steel ball increases sharply. When the incident velocity exceeds 340 m/s, the increase in residual velocity gradually slows down, tending towards a straight line. When the steel ball velocity is less than 330 m/s, the energy absorption of the UHMWPE laminated panels exhibits linear growth with increasing velocity, with a maximum energy absorption of 47.3 J. In the 327–340 m/s velocity range, the energy absorption of the laminated panels drops sharply from 47 J to around 30 J. In the 340 m/s–600 m/s velocity range, the decline in energy absorption gradually becomes more moderate, decreasing to around 20 J. Beyond 500 m/s, the energy absorbed by the UHMWPE laminated panels stabilizes with increasing velocity, and the fiber tensile failure is the main form of energy absorption of UHMWPE composite laminates under ballistic impact. The failure process of UHMWPE laminated panels presents a multi-stage failure mode, including fiber shear failure, tensile failure, and delamination. As the projectile’s incident velocity increases, the damage mechanism of the UHMWPE laminated panels transitions from tensile-dominated to shear plugging-dominated. Through similarity theory analysis, under certain conditions, the ballistic limit velocity and the dimensionless parameter of unit energy absorption for the UHMWPE laminated panels satisfy geometric similarity.