Structural Response of Piping to Internal Gas Detonation

Abstract

Detonation waves in gas-filled piping or tubing pose special challenges in analysis and prediction of structural response. The challenges arise due the nature of the detonation process and the role of fluid-structure interaction in determining the propagation and arrest of fractures. Over the past ten years, our laboratory has been engaged in studying this problem and developing methodologies for estimating structural response. A brief overview of detonation waves and some key issues relevant to structural waves is presented first. This is followed by a summary of our work on the elastic response of tubes and pipes to ideal detonation loading, highlighting the importance of detonation wave speed in determining flexural wave excitation and possibility of resonant response leading to large deformations. Some issues in measurement technique and validation testing are then presented. The importance of wave reflection from bends, valves and dead ends is discussed, as well as the differences between detonation, shock wave, and uniform internal pressure loading. Following this, we summarize our experimental findings on the fracture threshold of thin-walled tubes with pre-existing flaws. A particularly important issue for hazard analysis is the estimation of loads associated with flame acceleration and deflagration-to-detonation transition. We give some recent results on pressure and elastic strain measurements in the transition regime for a thick-wall piping, and some remarks about plastic deformation.

Boundary Layer Profile Behind Gaseous Detonation as it Affects Reflected Shock Wave Bifurcation

“…1 Gaseous detonations 2, 3 inside piping or vessels create both structural and thermal loads and in extreme cases may lead to plastic deformation or rupture. 4 When the detonation reaches a closed end, the boundary condition of zero flow velocity leads to the creation of a reflected shock wave that propagates back towards the point of ignition.…”

Development of a Numerical Model for an Expanding Tube with Linear Explosive Using AUTODYN

“…It is apparent that the tube expansion increases as the explosive load increases. For a pressure tube in the plastic deformation regime, catastrophic failure is associated with ductile tearing or plastic instability [19,24,25]. Rapidly expanding regions (the minor axis of the tube) are accompanied by rapid loss of stress-carrying capability and intense heating due to the dissipation of plastic work, and present risks of rupture [26].…”

Analytical solution of transverse shear strain vibration of gas detonation loaded tube near second critical speed (shear group velocity)

“…The structural response of shells to detonation loading was studied by researchers such as Tang [8], Reismann [9], de Malherbe et al [10], Simkins [11], Beltman and Shepherd [1,2] and Mirzaei et al [3,4]. Shepherd [12] summarized the state of knowledge about gaseous detonation loading of piping system.…”