Effect of pore geometry on compressive behavior in porous metals with unidirectional pores

Abstract

Rapid decrease of compressive stress in the plateau region is one of the issues in compressive behavior of porous metals. In this research, the compressive deformation behavior of porous metals with unidirectional pores was investigated experimentally and numerically. Cubic specimen with irregular pore geometry was used to avoid the effect of macroscopic shear bands which are commonly observed in porous metals with aligned pore geometry. Fractures of the cell walls were observed as well as a rapid decrease of compressive stress and thin ones preferentially fractured at the beginning. Equivalent strain localization at the vertical cell walls between pores was also confirmed by digital image correlation. Results of finite element analysis showed that von Mises stresses concentrate at the cell walls around fractured and locally deformed cell walls. This mechanism is considered to be the main cause of the fractures of the cell walls.