Prediction of Macroscopic Deformation Bands in Porous Metals with Unidirectional Through‐Pores

Abstract

The formation of macroscopic deformation bands constitutes undesired stress fluctuations in the compression of porous metals. This research is aimed at revealing the predictability of the formation of deformation bands in porous metals with unidirectional through‐pores. Finite element analyses of compression tests of such porous metals are conducted with the commercial code Abaqus/Standard and Explicit 2018. Three cubic specimens with different L/d (specimen edge length L, pore diameter d) but with the almost same porosity are prepared, and quasi‐static compression is simulated. The results suggest that the formation of horizontally propagated deformation bands is suppressed as L/d increases. A path search is performed to predict the location of deformation bands on a graph that represents equivalent plastic strain (PEEQ) distribution in the specimens. It is revealed that horizontally propagated deformation bands at compressive strain e = 10.0 pct can be predicted as the path with the largest mean of PEEQ at e = 1.0 pct when the following two conditions are met; the minimum PEEQ in the path has to be larger than zero, and the standard deviation of the PEEQ mean in candidate paths has to be sufficiently large.