In order to investigate the stress concentration phenomenon and analyze the distribution characteristics of the interlaminar stress in the hole edge region of composite laminates. Based on the generalized mixed variational principle, the generalized mixed finite element model for laminated plates with various stacking modes were established. The stress field variables were divided into the interlaminar stress and the in-plane stress, with the introduction of stress boundary conditions to ensure the physical continuity of interlaminar stresses between layers and the discontinuity of in-plane stresses between layers.The interlaminar stresses at the edge of the laminated plate hole were respectively analyzed through the thickness direction and the circumferential direction. Numerical examples demonstrated that the incompatible generalized mixed element could obtain more accurate stress singularity results than the 8-node three-dimensional solid incompatible displacement element results solved by the finite element software Abaqus. Stresses on both upper and lower surfaces of the laminated plate consistently reflected actual situations. The research indicates that compared with the displacement element, the incompatible generalized mixed element can more effectively capture the high stress gradient of the interlaminar stresses at the edge of the laminated plate hole, which provides a new idea for the optimal design of the laminate.
| 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 |