The High-rate Challenge

High-rate dynamics are described as a dynamic response from a high-rate (<100 ms) and high-amplitude (acceleration > 100 g_n) event such as a blast or impact. Systems which experience high-rate dynamics may undergo rapid changes that could lead to loss of economic investment or human lives. There are unique challenges associated with research of structural health monitoring for systems experiencing high-rate dynamics. A system subject to high-rate dynamic environments can often experience a sudden plastic deformation, and damage can extend to the structure, electronics, and/or sensors. Rapid state estimation for these systems can be used within a feedback loop to prevent further damage and complete failure. For example, rapid detection is required in the deployment of a blast mitigation system or in adapting control decisions for a hypersonic vehicle following a ballistic impact.

The high-rate problem contains many complexities that can be summarized as having:

large uncertainties in the external loads;
high levels of non-stationarities and heavy disturbances; and
generated unmodeled dynamics from changes in system configuration.

High-rate monitoring, damage detection, prognostics, and reactions systems must be capable of handling these three main particularities that differentiate high-rate dynamic systems from other systems.