Research On Failure Mechanism And Energy Absorption Characteristics Of Sandwich Panels With Aluminum Foam Core Under Contact And Non-contact Near-field Water Blast Loading

Sandwich structure consisting of two thin steel plates and aluminum foam possesses excellent energy absorption characteristic,as well as high flexural rigidity,which makes sure it has promising application prospect in the anti blast and impact field.Nowadays,the research work concerning the damage mechanism of sandwich panels with aluminum foam core subjected to underwater explosion is yet not perfect.The study on dynamic response of sandwich panels with aluminum foam core subjected to underwater contact explosion remains quite few.Therefore,investigating the failure mechanism and energy absorption characteristic of such structure has significant meaning.The main highlights in present thesis are as follows:(1)Taking the solid plate as study object,experimental and numerical investigations were carried out on the dynamic response under underwater explosion.The explosion experiment device was designed,which can quantitatively assess the blast resistance of target plate,and six experiments were carried out with such device.Based on the experiment results of solid plate,deformation and failure model were carefully categorized and analyzed under underwater explosion with different intensity.And the impact of remaining shock wave and structural fragments on the deformation of response plate.The finite element software LS-DYNA was used here to establish the numerical model,accurately simulating the deformation and failure mode.Discussion focuses mainly on the influenced of stand of distance and charge weight on the structure in terms of distribution of FSI pressure,deformation and energy absorption.(2)Taking the sandwich panels with an aluminum foam core as study object,experimental research was conducted on the dynamic response subjected to underwater contact and non-contact near-field explosion.Six specimens were produced using the epoxy resin adhesive.According to the experimental results,the deformation and failure patterns were classified.The effect of thickness configuration of face-sheets on the blast resistance was analyzed,and the results were further compared to the solid plate.(3)Numerical simulations were implemented to study the dynamic response of sandwich panels with aluminum foam core subjected to underwater explosion.The accuracy of numerical model was verified using the experimental results.Simulation gives insight into the response process,deformation/failure mode and energy absorption characteristic under various load intensity.The influence of structure parameters including front face thickness,back face thickness and equivalent face sheets thickness on the deformation and energy absorption was discussed.The work presented in this dissertation provides useful reference for deeply understanding the failure mechanism and blast resistance of sandwich panel with an aluminum foam core when subjected to underwater contact and non-contact near-field explosion.