High-temperature and dynamic mechanical characterization of closed-cell aluminum foams
•High-temperature and dynamic compressive responses of Al foams are studied.•Initial failure surface of Al foams is identified under high temperature conditions.•A theoretical constitutive model is proposed involving strain-rate effects.•The strain-rate dependent macro-mechanics models are numerical...
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Veröffentlicht in: | International journal of mechanical sciences 2022-09, Vol.230, p.107548, Article 107548 |
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Sprache: | eng |
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Zusammenfassung: | •High-temperature and dynamic compressive responses of Al foams are studied.•Initial failure surface of Al foams is identified under high temperature conditions.•A theoretical constitutive model is proposed involving strain-rate effects.•The strain-rate dependent macro-mechanics models are numerically evaluated.
Metallic foams exhibit great application prospects in some extreme working conditions such as high temperatures and/or high-velocity impact environments, but predominantly, their mechanical behavior has remained to be fully understood to date. In this study the uniaxial and biaxial tests are conducted on closed-cell aluminum foams at elevated temperatures. It is indicated that both drop stress and initial failure strength exhibit approximately linear relationship with the applied temperature, while the densification strain keeps almost at a constant value. The higher foam density or lower applied temperature, the larger the initial failure surface characterized in the von Mises - mean stress plane. However, the normalized failure surfaces nearly do not depend on foam density or temperature, and can be well fitted in terms of elliptical or parabolic function. Dynamic compressive tests under constant strain-rates reveal that the compressive strength is correlated to strain-rate positively, but the densification strain negatively. A novel rate-dependent constitutive model is proposed to describe the compressive constitutive behavior of Al foams. Finally, the crushable foam model with the tabular input of yield ratio approach can produce satisfactory numerical predictions compared to dynamic experimental results. This study provides new insights into the intrinsic mechanical properties of metallic foams under some extreme conditions.
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ISSN: | 0020-7403 1879-2162 |
DOI: | 10.1016/j.ijmecsci.2022.107548 |