Dynamic Response Of Aluminum Foam-filled Corrugated Core Hybrid Sandwich Panels Under Air Blast Loading

With high-porosity and superior strength-to-weight ratios,the aluminum foam has shown excellent energy absorption capability in the blast field.On the other hand,metallic corrugated core sandwich panels also attract more and more attention due to their high specific stiffness and load-carrying capability.Then through inserting the aluminum foam into the corrugated core,there is an innovative ship protective structure emerging,which is called aluminum foam-filled hybrid sandwich panel.Nowadays,the research about the aluminum foam-filled hybrid sandwich panel mostly focuses on the static mechanical behaviors,while the dynamic mechanical behaviors achieve much less attention.Under such circumstance,it's necessary to study the dynamic response of aluminum foam-filled hybrid sandwich panel subjected to near-field air blast or combined blast and fragment loading.Such work has great guiding significance for the engineering applications of sandwich structures.The main highlights in present thesis are as follows:(1)Taking aluminum foam-filled hybrid sandwich panel as the study object,8 experiments were carried to investigate the dynamic response under near-field air blast loading.The deformation and failure mode were carefully categorized and analyzed.Further insight was given into the influences of foam density and stand-off distance on the blast resistance of hybrid sandwich panel,as well as the comparison of blast resistance with empty corrugated sandwich panel and PVC foam-filled hybrid sandwich panel with equivalent mass.It turned out that filling aluminum foam improves the deformation mechanisim,reducing the plastic deflection of both front face sheet and back face sheet.And the higher the aluminum foam denstiy is,the more effective of such improvement will be.(2)Based on the experiment results,numerical simulations concerning the dynamic response were implemented in the finite element software AUTODYN.The response progress was analyzed.The blast resistance of aluminum foam-filled hybrid sandwich panel was evaluated in terms of FSI pressure,central velocity response,plastic deflection and energy absorption.The results showed that increasing the stand of distance can greatly lower the peak value of both shock wave and impulse.While varing the core configuration and filler density hardly affects the FSI pressure,yet has huge influence on the velocity response and palsti delfection of face sheets.(3)The synergetic effect of blast and fragment loading on aluminum foam-filled hybrid sandwich panel was investigated experimentally with 6 experiment cases.The effects of foam density,core configuration and stand of distance on the damage resistance of hybrid sandwich panel were studied.Then the damage caused by combined blast and fragment loading was compared with that caused by bare blast loading.It has been demonstrated that the combined loading can cause much more damage.When compared to the remaining shock wave,the prefabricated fragments are the main resource of damage laods in such loading situation.The work presented in this dissertation provides useful reference for the blast resistance design of aluminum foam-filled hybrid sandwich panel.