Abstract
A new micromechanics model based on the second-order moment of stress is established to investigate the effect of gas pressure on the nonlinear macroscopic constitutive relationship of the porous materials. The analytical method agrees well with numerical simulation based on the finite element method. Through a systematic study, we find that the gas pressure has a prominent effect on the nonlinear deformation behavior of the porous materials. The gas pressure can cause tension-compression asymmetry on the uniaxial stress-strain curve and the nominal Poisson's ratio. The pore pressure significantly reduces the initial yield strength and failure strength of the porous metals, especially when the relative density of the material is small. The gas phase also strongly compromises the composite strength when the temperature is increased. The model may be useful for the evaluation of mechanical integrity of porous materials under various working conditions and working temperatures. © 2008 Elsevier Ltd. All rights reserved.
| Original language | English |
|---|---|
| Pages (from-to) | 1231-1252 |
| Number of pages | 21 |
| Journal | International Journal of Plasticity |
| Volume | 25 |
| Issue number | 7 |
| DOIs | |
| Publication status | Published - 2009 |
| Externally published | Yes |
Funding
This work was supported in part by China Scholarship Council, by the State 973 Program of China (2007CB707702), by NSF CMMI-CAREER-0643726, and in part by the Department of Civil Engineering and Engineering Mechanics, Columbia University.
Keywords
- Closed-cell metal foam
- Elastoplastic behavior
- Micromechanics
- Porous material
- Pressure