ARMOR, SHIELDS AND HELMETS WITH HIGHLY PROPERTY-MISMATCHED INTERFACE MATERIALS TO REDUCE DYNAMIC FORCE AND DAMAGE

摘要

Armor/shields/helmets including highly property-mismatched interfaces (mismatch level of bulk materials and interfaces more than 60%) are disclosed, which provide protections against external dynamic loading such as blast loading, impact of projectiles and sharp-edged foreign objects. The mechanism to reduce dynamic force and damage is a specific material design using soft and ductile interfaces/adhesive layers to 1) bond or hold other layers/bulk materials with blast/impact/stab resistance, 2) reduce stress wave transmission and the maximum dynamic force, 3) decrease shear deformation of the inner layers behind interfaces, and 4) dissipate more energy due to blast and impact along the armor/shield/helmet surface. Therefore, less energy would be available to contribute to penetrate the armor/shields/helmets, or cause damage.

主权项

1. A layered structure for use in personal protection device or vehicles, comprising:
a first layer made of a first material; a second layer made of a second material, the second layer being an outer layer subjected to external loading; and a third layer made of a third material, wherein the first layer is located between the second and third layers and in contact with the second and third layers, wherein an impedance mismatch between the first and second materials is greater than 60%, the impedance mismatch being defined as IM=(P−1)/(P+1), where P is an impedance ratio defined as P=√{square root over (ρBEB/(ρAEA))}, where EA is a Young's modulus of the first material, EB is a Young's modulus of the second material, ρA is a density of the first material, and ρB is a density of the second material.