The objective of this project is the study of the energy absorption capacity of composite structures that are capable of dissipating the energy of an explosion by stable and progressive failing and as such of protecting the critical structural memebers (columns, bridge pillars, walls, ...) of civil ngineering structures. Therefore, the force necessary of initiation of progressive failing must be low, and as possible up to large deformations. The intended composite structures have a similar structure as sandwich panels, but the foam or honeycomb core is replaced by a grid of energy absorbing composite tubes. This research is new and innovative for several reasons:
* the energy absorption of composite circular and square tubes has only been studied in a range of impact velocities that is much lower than with blast loading. In blast loading, the incident shock wave has a velocity of 400m/s and more, and the total impact event only lasts a few tens of microseconds (in car crash simulations and bird strike experiments, the impact event typically lasts a few tens of milliseconds). Taking into account the viscoelastic and strain-rate dependent character of composite materials, the very large deformation rates must effect the energy absorption mechanisms, but there exist no experimental data, nor predictive models, to study this phenomenon.
* as mentioned above, composite structures are hardly studied to protect civil engineering structures against blast loading, allthough the cited publications in the automotive and aerospace industry show that the specific energy absorption capacity of composite materials makes them favourable condidate for such applications.
* finally the laboratory and full-scale explosion tests in this project will be performed with maximum instrumentation (digital high speed cameras, Digital Image Correlation DIC, Pressure sensors, laser doppler velocimetry, projection moiré). these extensive measurements must allow for a more fundamental investigation of the energy diisipation in composite structures under blast loading, based on reliable phenomenological observations.