闭孔泡沫金属几种不同建模方法的对比性研究

Comparative study of several different modeling methods for clossed-cell metal foam

为研究闭孔泡沫金属的单轴压缩性能,通过三种不同的建模方法,分别建立二维随机胞元、三维Kelvin和三维Voronoi泡沫金属细观模型。基于LS-DYNA软件分析三种不同建模方法表征下闭孔泡沫金属压缩力学性能的差异性,研究三种建模方法下泡沫金属的变形模式、应力应变响应变化规律。结果表明:二维随机模型更适合泡沫金属的压缩规律性研究,而三维模型则更适合泡沫金属压缩响应的预测与优化研究;二维随机胞元模型受其平面几何和网格的限制大多数情况下只能模拟孔隙率较低的闭孔泡沫金属,而Kelvin模型和Voronoi模型则能够较好地模拟孔隙率高的闭孔泡沫金属;相比于Kelvin模型和二维随机胞元模型,Voronoi模型内部结构更趋真实合理,能够更好地表征闭孔泡沫金属的压缩力学性能。

In order to study the uniaxial compression properties of closed-cell metal foam,three different modeling methods were used in this paper to establish 2 D random cell,3 D Kelvin and 3 D voronoi metal foam model.Based on the LS-DYNA software,the differences of the compressive mechanical properties of the closed-cell metal foam under three different models were analyzed.The deformation mode and the stress strain response of the metal foam under three models were studied.The results show that 2 D random cell model is more suitable for the study of the compression regularity of metal foam,and the 3 D model is more suitable for the prediction and optimization of the compression response of metal foam.The 2 D random cell model is restricted by its plane geometry,it can only simulate the closed-cell metal foam with low porosity in most cases.The Kelvin model and Voronoi model can simulate the closed-cell metal foam with high porosity.Compared with the Kelvin model and 2 D random cell model,the voronoi model is more realistic and reasonable,and it is able to better characterize the compressive mechanical properties of closed-cell metal foam.