Military platforms and structures, such as vehicles, ships, aircraft and buildings, must withstand transient shock, vibrations and other structural loads in a variety of demanding operational environments. These frequent and varying transient loads are often transmitted to occupants, which can degrade warfighters’ performance by creating discomfort and injuries. In addition, varying loads can lead to shortened service life for the military platforms, as well as the equipment inside. Currently, structures designed to achieve high stiffness for static loads (dead weight) typically can’t adapt to or dampen dynamic loads well. Conversely, structures designed for high damping do not carry conventional loads as efficiently.
DARPA's Structural Logic program seeks to enable structural systems for modern military platforms and buildings to adapt to varying loads and simultaneously exhibit both high stiffness and high damping. By demonstrating the ability to combine stiffness, damping and adaptive dynamic range in a single structure, the program should enable the design of military platforms with the ability to continually change their properties to match the demands of a broad range of dynamic environments.
Under the program, DARPA is developing innovative technologies for single elements and sub-assemblies to be integrated into structural designs. These building-block technologies have demonstrated passive adaptability and simultaneously showed high stiffness and high damping in response to a wide range of impulse and vibratory loadings. The next focus of the program is to extend the concepts and technologies from a single sub-assembly to an entire structural frame of a tactical platform.
DARPA plans to demonstrate the newly developed technologies applied to a high-speed boat (watercraft). The structural damping problems associated with high-speed boats are well known. Boat occupants are continuously subjected to loads associated with periodic wave motion and extreme slamming against the hull, resulting in whole-body vibration and repetitive shock loading in a dynamic operational environment. The dynamic loading conditions can result in impact injuries to the occupants, fatigue and loss of situational awareness, and damage to equipment on the watercraft. The goal is to apply Structural Logic concepts and technologies to the hull design and dramatically improve passively adaptive damping of the structural system without affecting the overall stiffness or strength of the hull or its hydrodynamic performance.
Dr. Aaron D. Lazarusaaron.firstname.lastname@example.org