In order to develop a hood with better pedestrian protection performance,firstly three types of straw energy absorption modules are designed,specifically circular,triangular and rectangular. Subsequently,the CSEAM sample with PA11 material is prepared and the finite element model is verified. Then,the human body injury protection effectiveness of the three types of Novel Straw-shaped structure Sandwich Hood (NSSH) is evaluated by simulation and the deformation mode is analyzed. The results show that the three NSSHs can significantly reduce pedestrian head injury,and the Triangle Straw-shape structure Sandwich Hood (TSSH) has the best protective effectiveness on human body injury. The deformation is uniformly diffused in a regular shape,and the peak of acceleration and impact force in each stage of the collision waveform is optimized by reducing the overall structural stiffness of the hood. Further analysis shows that the human body injury protection effectiveness of TSSH decreases with the increase of vehicle speed and impact angle,and the injury caused by TSSH is significantly lower than that of the original hood,indicating that raising the hood can reduce the impact angle to better protect pedestrians,while when the Ratio of Pedestrian height to Bonnet leading edge height Rh≤2.1 and Rh≥2.45,the head only impacts the hood and windshield,respectively. It can be used as the criterion of hood lift. The research results can provide support for the design of hood structure with better pedestrian protection effectiveness.
| 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 |