Local Damage Effects of X70 Steel Pipe Subjected to Contact Explosion Loading

Field explosion experiments were carried out to investigate the contact explosion damage effects of large diameter X70 steel oil-gas pipes. The contact explosion damage characteristics of pipes with different pipe wall thickness under various charge were analyzed. The experimental results show that the local damage of the pipe wall facing explosion is predominant and there is a petal-shaped crevasse. In addition, the fragments with abundant kinetic energy are formed. The dent or perforation phenomenon will occur after the opposite pipe wall is impacted by the fragment. By means of an explicit nonlinear dynamic finite element computer code LS-DYNA, the nonlinear dynamic response process of the steel pipe under contact explosion loading was numerically simulated with Lagrangian-Eulerian coupling method. The damage process of the pipe wall facing explosion and the after effects of opposite pipe wall due to the impact of fragment were described. The numerical simulation results are in good agreement with experimental data. The results can provide important reference for the blast resistant properties analysis and safety assessment of oil-gas pipes.