Initial defects such as cracks or bubbles will inevitably occur during sea ice condensation, which affect the mechanical properties of ice. To study the crack propagation and fracture characteristics of ice plate with initial defects, based on the peridynamic (PD) theory, the tangential stiffness coefficient for bond is introduced, a two-parameter PD method is proposed, and the two-parameter PD elastic-brittle model of ice material is established. The new model overcomes the limitation of fixing Poisson's ratio and inherits simplicity and stability of the traditional bond-based PD method. The model is verified by simulating the continuous deformation of thin plate and the three-point bending test of sea ice. Furthermore, effects of Poisson’s ratio, initial crack defects, bubble defects, ice grain size, defect shapes and multi-bubble defects on the mechanical properties of sea ice are investigated. The results indicate that the two-parameter PD elastic-brittle model is feasible to predict the continuous to discontinuous failure of sea ice, and the initial defects greatly affect the initiation time and failure mode of the ice structure.
| 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 |