Experimental Fluid Mechanics and Aerodynamics Laboratory

Shock Interactions with Composite Structures

Blast Wave Interactions with Metallic and Composite Structures

The mutual interaction between a blast wave and a structure is the subject of this research. Impingement of blast waves on structures can cause a reflection of the wave off the surface of the structure followed by a substantial transient aerodynamic load, which can cause significant deformation of the structure. This deformation can alter the overpressure, which is built behind the reflected shock. In addition, this complex aeroelastic interaction between the blast wave and the structure can induce reverberation within an enclosure, which can cause substantial overpressure through multiple reflections of the wave.

The long term objective of this work is to alleviate the phenomenon of overpressure which is associated with blast wave reflections by designing surfaces of structures which will defocus reflected waves and somehow induce a ¡°leakage¡± the overpressure, which will attenuate their strength. The aeroelastic response of composite materials to blast wave impact and their effect on the overpressure behind the reflected wave which affects the crew in closures is not known yet.

The present work focuses on better understanding the phenomenon involved in these complicated interactions by using simplified geometries and flow fields. Along these lines the following experiments were carried out:

• Plane shock wave impacting ¡°face on¡± a thin aluminium flat plate
• Plane shock wave impacting ¡°face on¡± a stainless steel flat plate
• Plane shock wave impacting ¡°face on¡± composite material flat plate
• Response of an enclosed rectangular structure to multiple internal shock wave reflections
• External sound wave excitation through internal shock wave impact