No abstract

The dynamic response of composite explosion containment vessels has been widely reported by experimental observations. In this study, we propose an analytical method to predict the dynamic response of open-ended cylindrical composite shells subjected to internal blast loading. The cylindrical composite shell has an out fiber composite shell with an inner steel liner, in which the outer fiber composite shell is simplified as a single elastic layer by an effective modulus in the hoop direction. Considering the impact between two layers during the dynamic response, the analytical solution for response histories of two layers could be obtained. Finite element analysis on the double-layer model is also conducted by ls-dyna. The analytical solution and the simulation result agree well, which demonstrates that the current analytical method can be employed in the design of this composite structure under blast loading.

When under explosion, the cover of an explosion containment vessel will bear a much higher intensity of impulse loading because of the reflection and superposition of the shock waves, especially in cylindrical vessels. To assure the integrity of the explosion containment vessel closure, a thick steel plate is often used as the cover, while in the supporting part of the shell thickening or reinforcement is also needed. Tooth locks are widely used as a quick-actuating closure. Experiments and numerical simulations were conducted to examine the protective performance of the tooth lock covers. The deformation and failure results agree well with the experimental data. Three types of covers with different number of teeth are calculated. Main factors and weak spots are analyzed with the experimental data and the simulation data. This study may help in the designing of explosion containment vessels and evaluating the protective performance of vessel covers.

Blast-proof units are used in explosive production applications to isolate the adjacent unit from damaging shockwave effects in the event of an accidental explosion. The damage is mainly caused by the transmission wave through the wall and the diffraction wave over the upper edge. Investigation on the blast flow field in blast-proof units subjected to internal blast loading is studied by numerical simulation in the current paper. The influence of the height of the proof unit is analyzed and on the cap situation is studied. The result shows that increasing the height of blast-proof units may not have a positive effect on reducing the diffraction wave, because it may enhance the reflection wave, which might have a greater effect than the diffraction wave. We can reduce the shock wave in the next unit by adding a cap, which is very effective. The study may contribute to further understanding on the experiment results and the design of blast-proof units.

In our previous papers, it has been reported that when rings and shells are subjected to an internal uniformly-distributed pressure pulse, dynamic elastic buckling due to the nonlinear coupling between the breathing mode and bending modes may occur and further cause the strain growth phenomenon in explosion containment vessels. In this study, the influence of defect distribution on dynamic buckling of plane-strain rings under internal uniformly-distributed pressure pulse is studied, in which three cases with one defect, six defects and twelve defects are employed in the finite element model. It is found that defects influence the initial buckling response shapes and occurrence of dynamic buckling. However, the excited bending mode is the same for the different defects distribution cases.