Analysis of defects on the compressive behaviors of open-cell metal foams through models using the FEM

Effects of three different types of morphological defects - missing cell struts, filled cell faces and curved cell struts - on the compressive behaviors of open-cell metal foams are investigated using finite element method (FEM) in this study. The imperfect model is individually constructed by introducing the corresponding type of defect at the random locations of three-dimensional intact Kelvin structures. Emphasis is placed on the quantitative analysis of effects of defects on the effective Young's modulus, yield strength and performance of densification of open-cell metal foams. Furthermore, the influences of model domain size and average analysis on the numerical results are investigated for each type of imperfect model, respectively. Comparing the weakening effects caused by different types of defects, it shows that the missing cell struts lead to the maximum decrement for the mechanical properties of open-cell metal foams in all. However, the filled cell faces has a more significant effect on the onset of densification of open-cell metal foams, and produces more weakening on the yield strength than that of the effective Young's modulus different from other types of defects.