Analyses on the Elasto-Plastic Behavior of Open-cell Foams

Abstract

The dominant deformation mechanism of lightweight open-cell foams which are composed of an interconnected network of solid struts is the flexural deflection of each slender cell strut Thus a slender beam under different boundary conditions can be employed to analyze the elasto-plastic behavior of open-cell foams In the study the elasto-plastic deflection of a rectangular cross-section slender beam made from either a perfectly plastic or a strain-hardening solid and subjected to a concentrated force is first analyzed numerically by using a finite element software ABAQUS and then compared to the theoretical results derived from conjugated beam method Furthermore the normalized concentrated force and flexural deflection of the slender beam are defined as the values at any instance divided by those at the outset of initial yielding It is found that the relationship between the normalized concentrated force and flexural deflection can be described well by a simple function regardless of the boundary condition of the slender beam Meanwhile the effects of boundary condition concentrated force location and cross-sectional shape on the normalized simple function are insignificant when the concentrated force is loaded at the critical section of the beam As a result the normalized simple function of the slender beam can be utilized to analyze the elastic-plastic stress-strain relationship of open-cell foams Finally the theoretical elasto-plastic behavior derived here is compared with the experimental results of uniaxial compression test for aluminum alloy foams to verify its validity and accuracy

Date of Award	2020
Original language	English
Supervisor	Jong-Shin Huang (Supervisor)