Kelvin结构开孔泡沫材料的弹性性能研究

Elastic Properties of the Kelvin Foams with Open-Cells

采用一修正的十四面体结构模型(Kelvin结构模型)对开孔泡沫金属的弹性性能进行研究,对低密度开孔泡沫材料表现出不可压的特性进行了分析。该模型考虑作用在泡沫筋条上的弯矩、剪力和轴向力,以及轴向力的平衡。修正模型的数值计算结果与实验结果及其他模型的结果进行了对比,结果表明修正模型计算的杨氏模量比原有模型的略有提高,筋条截面为星形的修正模型计算的结果与实验比较符合。在密度等同的条件下,筋条截面惯性矩越大的开孔泡沫材料,其弹性模量也越大,而泊松比则越小。Kelvin结构的开孔泡沫材料的泊松比随相对密度的减小而趋于0.5。

The elastic properties of the Kelvin foams with open-cells were theoretically examined with an improved model taking bending moment,shear force,axial force and equilibrium of axial forces into account.The predicted elastic properties were compared with those obtained by the other theoretical models and the experimental results.It is found that the predicted modulus of ideal Kelvin foams with a Plateau Border coincides reasonably well with the experimental results,and slightly larger than the existing model.The Young's modulus of the foam with the strut of larger second moment of the cross sectional area gets higher than that of the foam with the same relative density and the Poisson's ratio in reverse.The predicted Poisson's ratio for open-cell foams of very low relative density tends to near 1/2.