Morphological Analysis, Digital Modeling, and Mechanical Simulation of Carbon Foam

A carbon foam sample is investigated in three steps. Analysis of the pore distribution of the foam is based on its computed tomography data set. For this purpose, an automatic segmentation algorithm is improved: Random access memory usage can be reduced up to two thirds. Effective radii of detected pores lie between r eff = 1 μm and r eff = 160 μm. Small pores with r eff < 8 μm are spherical and occur abundantly. Large pores resemble ellipsoids, and are aligned to each other. After analysis, carbon foam is modeled digitally. Void space is approximated by overlapping ellipsoids, which mimic the previously determined distribution of pores. Modeling is subdivided into two steps: First, around 9600 ellipsoids are packed in a virtual process. For efficiency, inner distances of intersecting ellipsoid surfaces are approximated. Then, small spheres are placed randomly within the remaining material. Altogether, a model foam with 100 000 pores is generated. Multiple linear elastic mechanics simulations are conducted to compare mechanical properties of carbon foam and digital model. Depending on spatial direction, the elastic modulus of the real foam is between 10 % and 45 % larger than the modulus of the model. Finally, effective mechanical properties are compared with models which can be found in literature