Recent Studies on Hydrostatic and Shock Initiated Implosions Occurring within a Confining Tube
Sachin Gupta (University of Rhode Island), James LeBlanc (Naval Undersea Warfare Center (Division Newport), Newport, RI 02841), Christopher Shillings (University of Rhode Island), Arun Shukla (University of Rhode Island)
Eringen Medal Symposium in honor of G. Ravichandran
Wed 9:00 - 10:30
Salomon 001
A series of experiments were conducted to study the hydrostatic and shock initiated implosion of a tube (implodable volume) occurring within a closed outer tube. The outer tube has an inner diameter of 0.177m and a length of 1.82m. The experiments were conducted with ductile materials (aluminum and polycarbonate) as well as with brittle materials (acrylic). Various parameters, including the ratio of the implodable volume diameter to outer tube diameter (d/D) and the implodable volume length to diameter ratio (L/d), were varied to study the effect of geometric parameters on the mechanics of implosion. Hydrostatic collapse of the tubes was caused at 95% of the critical buckling pressure by using an initiator mechanism. In the shock initiated experiments, the implodable volumes were hydrostatically loaded to 90% of the critical buckling pressure and subsequently, a RP-80 detonator cap was utilized to generate a shock wave in the surrounding fluid resulting in the initiation of the collapse. The pressure histories generated by the implosion of the cylinders and the UNDEX wave, in the case of the shock initiated tests, were captured using dynamic pressure transducers mounted on the inner surface of the outer tube. High speed images of the collapse process were also captured using Photron SA1 cameras to better understand the collapse mechanisms and failure modes of the specimens during the experiments. Computational models of the implosion experiments were developed using the DYSMAS software package, and the computational pressure profiles as well as collapse shapes were compared to the experimental data.