The initial yield behavior of Alporas closed-cell aluminium foams with relative density 8.5% under biaxial loading has been experimentally investigated using the Arcan apparatus and the universal testing machine (INSTRON 5544). The experimental yield surfaces measured from biaxial experiments are compared with various proposed phenomenological yield surface models. The comparison result indicates that the experimental data are consistent with both Miller and Deshpande and Fleck criteria. Biaxial experiments have been carried out on aluminium foams at various loading velocities to study the effect of strain rate on the initial yield surface. The results showed that the initial yield stresses of Alporas closed-cell aluminium foams are not sensitive to the equivalent strain rate ranged from 7.0×10-3 s-1 to 1.0×10-1 s-1.
| 科 Family | 属数 Number of genus | 种数 Number of species | 占总种数比例 Percentage of total species (%) | 属 Genus | 种数 Number of species | 占总种数比例 Percentage of total species (%) |
|---|---|---|---|---|---|---|
| 鹅膏菌科Amanitaceae | 2 | 11 | 5.26 | 鹅膏菌属 Amanita | 10 | 4.78 |
| 小菇科 Mycenaceae | 2 | 12 | 5.74 | 丝盖伞属 Inocybe | 5 | 2.39 |
| 多孔菌科 Polyporaceae | 8 | 14 | 6.70 | 蜡蘑属 Laccaria | 5 | 2.39 |
| 红菇科 Russulaceae | 3 | 23 | 11.00 | 小皮伞属 Marasmius | 6 | 2.87 |
| 小菇属 Mycena | 11 | 5.26 | ||||
| 光柄菇属 Pluteus | 5 | 2.39 | ||||
| 红菇属 Russula | 17 | 8.13 | ||||
| 栓菌属 Trametes | 5 | 2.39 |