Mechanical performance of reverse-engineered resin foam structures developed by image processing on the computed tomography data: A revisit

Abstract

Using digital design methods, additive manufacturing processes enable us to create novel complex structures. In the current study, 3 and 10 ppi, density-graded, and merged foams (digitally joined 3 and 10 ppi) were reproduced from computed tomography data of the commercially available steel foams using MSLA (masked stereolithography). The mechanical performance of the foams has been characterized by quasi-static compression testing. Density grading increases the slope of the plateau regime and reduces the densification strain. Merged foams at high relative densities (ρrel~35 %) showed the highest energy absorption capacity, specific strength, and densification strain. 3,10 and density-graded foams deform by bending of struts. In the case of merged foams, the bending-dominated structure has been transformed into a stretch-dominated structure. The power exponent (n = 0.72) delivers the deformation mode of the strut, revealing stretch-dominated behavior. Moreover, additively manufactured resin foams have a lower scattering in mechanical properties than conventionally manufactured metal foams because structures can be remanufactured with the same cell/strut dimensions and imperfections.