Dynamic Response of Closed-cell Aluminum Foams
|關鍵字:||霍普金森桿;封閉式泡沫材料;動態力學行為;數值模擬;可壓縮泡沫模型;SHPB;closed-cell foam;dynamic response;FEM simulation;crushable foam model|
This study aims to investigate the dynamic response of APORAS closed-cell aluminum foam by means of experiments and numerical simulations. Toward this end, a PMMA based split Hopkinson pressure bar (SHPB) has first been established. A series of dynamic crushing experiments are subsequently conducted in an effort to access the effects of the specimen geometry, the relative density as well as the strain rate on the mechanical response of APORAS closed-cell foam studied. It is found that mechanical response is not sensitive to the specimen geometry while becomes increasingly higher as the specimen relative density increases. These two conclusions agree with results obtained from quasi-static crushing experiments. Also the dynamic response is seen to be higher than the quasi-static one, although the effect of strain rate is not significant in the tested strain rate range. Regarding the simulations, numerical models mimicking experimental set-up have been developed using the commercial FE package ABAQUS. The bars are assumed to be linearly elastic while the constitutive relation for the foam specimen is chosen to be the crushable foam which has been built in ABAQUS. Along with appropriate boundary conditions, the developed numerical models are bale to reproduce the experimental results successfully. Furthermore, the developed numerical models are utilized to perform parametric studies on the influences of bar lengths and strain rates.