Fabrication and optimization of combined open-and-closed-type cellular metals

• A simple method is used to produce open-and-closed-type cellular metals.
• FEM analysis is used to direct the job of structural optimization.
• Compressive strength of the pipe-gridded is predicted by numerical modeling (FEM).
• The porous metal has much better compressive strength than typical cellular metals.

A model of an open-and-closed-type cellular metal was designed with 3D software, and samples with the expected structures were fabricated from stainless steel using machining and electric resistance welding techniques. Then, quasi-static compression experiments were carried out to evaluate the deformation mechanism. The compressive stress–strain curves of the samples exhibited two stages of discontinuous elastic deformation with a stage of plastic deformation between them, which is disadvantageous for practical applications. In order to optimize the structure, finite element method (FEM) analysis in which pressure was applied to the model was performed to obtain the stress distribution and deformation behavior of the samples and identify their weak regions. On the basis of this FEM analysis, a new model was proposed, and its improvement on the old structure was verified by FEM analysis and the test results for new samples.