The influence of magnetic field on ballistic performance of aramid fibre and ultrahigh molecular weight polyethylene

• Ballistic tests conducted on Kevlar and UHMWPE within a magnetic field.
• Repulsion force created by opposing magnet poles reduced the impact momentum.
• High speed camera images showed no perforation on Kevlar due to magnetic field.
• Standoff distance between magnets has an effect on the repulsion force.

An innovative method is introduced here whereby using two sets of arrays of rare earth magnets aligned opposite each other in order to create a repulsion force owing to the like poles when facing close to each other. Ballistic test samples of aramid fibre (Kevlar K29) and ultrahigh molecular weight polyethylene (UHMWPE) were sandwiched by two sets of opposing magnets. Ballistic test was conducted using a gas gun with a 7.62 mm diameter projectile at a velocity ranging from 160 to 220 m/s. High speed camera was used to capture the ballistics testing and it shows that the magnetic repulsion force created by the opposing rare earth magnets managed to suppress the projectile from advancing into the front face of the aramid fibre. Similarly, when magnets were used, the UHMWPE sample shows the projectile perforated through the first few sheets and finally rested on the last sheet showing partial perforation.