On the Adequacy of Shell Models for Predicting Stresses and Strains in Thick-Walled Tubes Subjected to Detonation Loading

Abstract

This paper analyzes the adequacy of shell models for predicting stresses and strains in thick-walled tubes subjected to detonation loads. Of particular interest are the large axial strains which are produced at the inner and outer surfaces of the tube due to bending along the tube axis. First, comparisons between simple shell theory and a static finite element model are used to show that the axial strain varies proportionally with wall thickness and inversely with the square of the axial wavelength. For small wavelengths, this comparison demonstrates nonlinear behavior and a breakdown of the shell model. Second, a dynamic finite element model is used to evaluate the performance of transient shell equations. This comparison is used to quantify the error of the shell model with increasing wall thickness and show that shell models can be inaccurate near the load front where the axial curvature is high. Finally, the results of these analyses are used to show that the large axial strains which are sometimes observed in experiments cannot be attributed to throughwall bending and appear to be caused instead by non-ideal conditions present in the experiments.

On the vibrational responses of thin FGM tubes subjected to internal sequential moving pressure

“…Smeulers et al [28] analyzed mode coupling (excitation of circumferential bending modes, coupled with the initial hoop stress) that can occur in tubes under different conditions, by considering the effect of limited plasticity. Bitter et al [29] have presented the capability of the shell models to predict stress and strain in thick-walled tubes under detonation loads. Bitter et al [30] proposed a simplified model for forecasting the axial displacement as well as stress/strain in tubes imposed to shock loading, while the effects of rotary and radial inertia of the tube were neglected in their model, thus the prediction represented only a spatially averaged response of the tube.…”

Deformation and fracture of cylindrical tubes under detonation loading: A review of numerical and experimental analyses

“…• Bitter et al [91] analyzed the capability of shell models for predicting stresses and strains in thick-walled tubes under detonation loads.…”

Impulsive Motion in a Cylindrical Fluid-Filled Tube Terminated by a Converging Section

“…Regarding the axial strains, assuming zero axial stress, 4 and using shell theory yields e z ¼ Àe h [21]. This implies that the axial strains are produced through the Poisson effect.…”