Structural Health Monitoring of M1114 High Mobility Multipurpose Wheeled Vehicle Armor System

摘要

The M1114 High Mobility Multipurpose Wheeled Vehicle (HMMWV) has been the workhorse vehicle of the U.S. Armed Forces in Afghanistan and Iraq. Donald Rumsfeld, Secretary of Defense, was faced with massive public criticism in 2004 for not equipping our military personnel in Afghanistan and Iraq with M1114s that had the proper ballistic armor. In May 2004, a $618M Senate Bill was passed to increase the production level of HMMWVs and improve their ballistic protection capabilities while minimizing additional weight. While the military is taking advantage of using composite armor on the HMMWV, it does not have a rigorous method to detect, locate, and quantify damage on a two-layer composite armor system. Structural Health Monitoring (SHM) is the process of implementing a damage detection and characterization strategy for engineering structures. Damage is defined as changes to the material and geometric properties of a structural system, including changes to boundary conditions and system connectivity, which adversely affect the system's performance. An active SHM system was developed to detect, locate, and quantify damage on a two-layer composite armor (HJ1 composite with ceramic frontal plates) that encounters impact from a 0.30 caliber armor piercing projectile. An adaptive version of a one-at-a-time experiment was used during this research. Base line testing was performed to provide information on the structural properties and wave propagation characteristics of the material. Ballistic testing was completed to replicate David Fecko's experiment of maximum V(sub 50) velocity of 947 meters per second and a ceramic-to-composite ratio of 60/40%.