Damage Distruction And Energy Absorption Mechanism Of Multi-cavity Aluminum Alloy Components Filled With Aluminum Foam

During the service life of a structure,in addition to bearing static loads,dynamic loads such as seismic and wind loads,it is inevitable to be subjected to external loads impact.When the component is impacted,damage and destruction may occur,leading to the overall collapse of the structure,causing huge losses to life and property.In order to protect bridge structures,station structures,and adjacent structures near the track from damage after impact,this paper proposes an easy-to-install,energy-effective multi-cavity protective component filled with foam aluminum.A series of research work has been carried out around the deformation performance,energy consumption mechanism,and section optimization design of such components,using experimental research and numerical simulation methods.The specific content is as follows:(1)Ninety-six groups of thin-walled tube bundles were subjected to axial impact tests using a drop hammer impact testing machine.The study investigated the effects of impact velocity,wall thickness of the thin-walled tubes,width of the cross-section,presence or absence of foam filling,and thin-walled material on the deformation and energy consumption of the components under the action of impact force.A refined model was established using the finite element software ANSYS/LS-DYNA to study the impact process,energy dissipation,interaction between foam aluminum and thin-walled aluminum alloy,and interaction between multi-cavity bundles,revealing the working mechanism and energy absorption characteristics of the components.The research results indicate that the energy absorption ratio of the multicavity bundle filled with foam aluminum and thin-walled aluminum alloy is above 90%,with outstanding energy absorption performance.When the absorbed energy is consistent,the deformation value of the multi-cavity bundle filled with foam aluminum is lower than that of the single-cell bundle.Due to the ‘combination effect’,the impact energy absorbed by the multicavity bundle is greater than the sum of the energy absorbed by each single cell.The influence of thin-walled material on the energy absorption of the multi-cavity bundle filled with foam aluminum is mainly determined by its synergistic performance with foam aluminum.(2)Using a drop hammer impact testing machine,a lateral impact test study was conducted on 30 groups of foam-filled aluminum thin-walled aluminum alloy multi-cavity plates.The study investigated the effect of impact velocity,partition wall thickness,and number of partition walls on the deformation and energy dissipation of multi-cavity plates under the action of impact force.A refined model was established using the finite element software ANSYS/LSDYNA to study the impact process,energy dissipation,and interaction between foam aluminum and thin-walled aluminum alloy,revealing the working mechanism and energy absorption characteristics of the multi-cavity plate.The research results showed that there were three modes of damage for thin-walled aluminum alloy plates filled with foam aluminum.Under the same deformation,the energy consumption of both single-cavity and multi-cavity plates roes with the increase of impact velocity,partition wall thickness,and number of partition walls.With a certain number and thickness of aluminum alloy partition walls,the energy absorption ratio of the multi-cavity plate was significantly improved compared to the single-cavity plate,and its energy absorption capacity was outstanding.For foam-filled multi-cavity plates,most of the impact energy was absorbed by the outer thin-walled aluminum alloy,followed by the aluminum alloy partition walls,while foam aluminum only absorbed a small portion of the impact energy.(3)Using response surface methodology,the wall thickness and cross-sectional width of both hollow and foam-filled aluminum single and multiple chamber tubes were taken as design variables,with improvement of the specific energy absorption ratio of the structure as the optimization objective.The tube bundles were then subjected to energy absorption optimization design through the optimization algorithm of MATLAB toolbox,and the optimal wall thickness and cross-sectional width of the tube bundles under the optimal specific energy absorption were obtained.Response surface methodology was utilized to design response surface experiments according to the Box-Behnken design principle,with specific energy absorption ratio and ratio of specific energy absorption as response values.The energy absorption optimization design of the multi-cavity plates was then conducted through the optimization algorithm of DesignExport toolbox,and the optimal specific energy absorption ratio and ratio of specific energy absorption under the impact velocity,number of partitions,and partition wall thickness of the multi-cavity plates were obtained.(4)Based on the aforementioned research findings,a full-scale multi-cavity plate with internal partitions of various shapes,such as rectangular,triangular,trapezoidal,and circular,was innovatively proposed.The specimen was studied in terms of damage mode,impact forcedeformation curve,energy absorption,energy absorption indicators,and parameter analysis through finite element software ANSYS/LS-DYNA.The research results indicate that foamfilled aluminum thin-walled alloy multi-cavity plates exhibit better energy absorption efficiency,and the aluminum content and cross-sectional shape to some extent determine the energy absorption rate of the specimen.Under the same deformation,the multi-cavity plate with a small triangular cross-section is the optimal choice in terms of both total energy absorption and specific energy absorption efficiency.