Research On Dynamic Response And The Vulnerability Of Storage Tanks Influenced By Blast Fragments

In chemical parks or plants,domino effect caused by blast fragments is a typical highimpact low-probability(HILP)accident scenarios,once domino effect occurs,it will cause catastrophic accident consequences.The dynamic response and vulnerability of large steel storage tanks under the impact of blast fragments were studied in detail,contributing to prevent and reduce the loss caused by the explosion.The main contents included in this thesis are as follows:(1)Simulation experiment study on small-scale tank impacted by conical projectile.The semi-structure cylindrical shells were used as small-scale vertical tanks,the conical projectiles were used as small-scale fragments,the impact velocity and residual velocity of conical projectiles were measured by Model 57 infrared optical sensor,changing the impact angle by designing the base with different tilt angles on which fixed small-scale tank,and the failure behavior law of small-scale tanks with different wall thickness impacted by conical projectiles with different impact angles was studied.(2)Theoretical analysis and numerical simulation of conical projectile impacting smallscale tank.The theoretical formula for calculating the residual velocity of conical projectile penetrating tank with different impact angles was deduced.The experiment conditions of conical projectile impacting small-scale tank was simulated by using ANSYS/LS-DYNA code,and the accuracy and reliability of the finite element model were verified,which laid foundation for the dynamic response of large tank impacted by blast fragments.(3)Analysis of random parameters of blast fragments generated from chemical vessels.Through analysis of research results of domestic and foreign scholars on random parameters of blast fragments,strong applicable and high degree of approval distributions of random variables were selected.The value range of parameters of blast fragments generated from 150m3 hemispherical head horizontal tank were calculated to provide data support for the blast fragments impacting large tank and the study of vulnerability.(4)Dynamic response of large tank impacted by blast fragments.A finite element model of large dome tanks and blast fragments was established using ANSYS/LS-DYNA code,the movement,deformation,stress of tank structure were analyzed during the process of impact,the change regulation of dynamic response of large tank influenced by tank volume,Impact position,blast fragments type,velocity,mass and impact angle was studied.(5)Analysis of vulnerability of large tank under the impact load caused by blast fragments.Based on the maximum plastic strain failure criterion,the limit state equation of tank's rupture failure was established,the vulnerability curves of large dome tank impacted by blast fragments were drawn using Monte-Carlo specimen computation,and the sensitivity of random variables was analyzed,which has important reference significance to the safety of the tank before the domino effect and the loss assessment after the domino effect.