Energy Absorption Performance And Multi-objective Optimization Design Of The Aluminum Foam Filled Energy Absorption Connector Under Impact Loading

In recent years,large-scale terrorist attacks persisting all around the world,explosionproof and shock-proof designs for civil buildings and large-scale public buildings have received increasing attention in the field of civil engineering.It had been found that the average crushing force of the metal foam filled tube was greater than the sum of the average crushing force of the individual thin-walled metal tube and the individual metal foam material,which had been proved that the metal foam filled tube component performed stronger load bearing capacity and energy absorption performance,and it possessed the ability to serve under the extreme adverse conditions such as explosion impact and highspeed collision.In this paper,a novel energy absorption connector filled with aluminum foam were proposed to absorb blast energy and reduce the blast load on the buildings during explosion,which were embedded in blast-resistant fa?ades and buildings.the energy absorption connector were fabricated from mild steel as face plates and closed cell aluminum foam as core energy absorption materials.The impact loading tests and quasi-static compression loading on the proposed energy absorption connectors were conducted to study their energy absorption performance.It also established a refined finite element model to develop numerical simulation study.Finally,based on the experimental results and finite element research,multi-objective optimization design was carried out in this paper,the specific contents are as follows:(1)Designed and fabricated two different forms of energy absorption connectors,drop hammer impact testing system was used to conduct the impact loading tests on these connectors,the indicators which could evaluate the mechanical properties and energy absorption performance were also given.In the tests,the effects of filled aluminum foam,pleated plate thickness,angle of the pleated plate,folding radius of the pleated plate on the energy absorption performances of the energy absorption connectors were investigated.(2)The energy absorption performance of connectors under quasi-static compression loading was studied by MTS electronic universal material testing machine,the effects of filled aluminum foam,shape of the pleated plate on the failure mode,he mechanical properties and energy absorption performances of the connectors were studied.Compared with the results of impact loading tests to analysis the failure mode and energy absorption performance of the energy absorption connectors under two different load conditions.(3)Refined finite element model was established and finite element software LSDYNA was used to simulate the drop hammer impact tests,results of the impact loading tests were validated by consistent FE results of compressive force-displacement curves.With the finite element method,the parameter of experiments were enlarged and the influence of impact velocity,aluminum foam density,steel grade,pleated plate thickness and impact weight were considered.(4)In order to further improve the energy absorption performance of the connectors,the specific energy absorption and the peak force of the energy absorption connectors were selected as the optimization objectives,The influence of pleated plate thickness,the height of connector,the bending angle of the pleated plate,and the compression length of the steel plate on energy absorption performance were studied,which could provide certain guiding significance for the application of this energy absorption connector in practical engineering.