Research On The Failure Mode Of Framework Whalf Under Blast Loading

In the fields of modem hydraulic structures,the hydraulic structures is extremely easy to become a target in the consequence of the very extreme sudden loads,such as wars,If the hydraulic structures are subjected to underwater blasting,it will results not only the local damage,furthermore,there will cause the overall damage of the structure.So in the considering of the underwater explosions which can casue disaster to the framework wharf,this paper mainly focuses on the structure’s dynamic responses and failure models.Firstly,the underwater explosion was studied by numerical simulation.In this paper,numerical simulation of three-dimensional infinite water and near air-water surface underwater explosion problem was conducted based on the multi-material ALE method through the sof-tware of ANSYS/LS-DYNA,and The accuracy of the simulation method was verified by comparing with the empirical formula.Simulation reproduced the process of the detonation products,water and air during the explosion,and compared the characteristic of pressure between the infinite water and near air-water surface underwater explosion:in the condition of the depth of detonation remaining unchanged,the influence of air-water surface on shock wave is mainly reflected in reducing the pulse width of incident shock wave and reducing the peak pressure of shock wave with the decrease of sounding depth;At the same time,the density distribution near air-water surface was qualitatively analyzed,and the characteristic and process of water column under different detonation depths were reproduced in the simulation.Through taking the shock wave as an extreme load and combining with the actual structure,a fully coupled model of underwater explosion was established for two-storey wharf framework.Compared with the experimental results,the correctness and reliability of the coupling modeling method and the material model are verified.The dynamic response and the failure model of the structure were also analyzed.The dynamic response and failure mode of wharf structure were studied by considering different initiation depth,distance and charge dosage.The results show that the damage of the structure is most serious when the explosive detonates near the first floor of the structure.When the quantity of explosive and the depth of detonation remain unchanged,the structure is prone to shear failure with the decrease of the detonation distance.With the increase of the explosive dosagesthe pressure of the shock waves structure become larger and larger,and the damage and failure model develop from local damage to overall shear failure gradually.The results of this paper may offer some practical significance for the design and engineering protection of the wharf structure which may suffer the extreme load.