Manually operated solar shades have a significant impact on indoor visual comfort.This research investigates occupants’appropriate seating position and view direction in a west-facing office cell using a previously d...Manually operated solar shades have a significant impact on indoor visual comfort.This research investigates occupants’appropriate seating position and view direction in a west-facing office cell using a previously developed shade behavior model.The non-dominant sorting genetic algorithm(NSGA-II)based Multi-objective optimization was adopted to identify the optimal and near optimal solutions.Daylight and glare index were used as two visual comfort objectives for optimization and robustness of optimization results against shade behavior uncertainty that was analyzed using statistical analysis.Results show that near optimal solutions can be used instead of the optimal one since they provide more flexibility in seating positions while maintaining almost the same visual comfort performance.And thus,the appropriate seating position considering occupants’preference is 1.5m away from the external window with two view directions near parallel to the window for west-facing office rooms.展开更多
This paper used the Hyper Mesh and LS-DYNA software to establish a dummy-seat finite element simulation model. The head, chest and neck injury of the dummy were analyzed respectively in the frontal impact and rear imp...This paper used the Hyper Mesh and LS-DYNA software to establish a dummy-seat finite element simulation model. The head, chest and neck injury of the dummy were analyzed respectively in the frontal impact and rear impact. It was indicated that modification of seat was needed to meet the requirements. The simulation results showed that the original model cannot provide effective protection for the occupants and need for structural improvements. According to the simulation results of deformation and stress conditions of the seat parts, the original seat structure was improved and optimized for four improvement schemes, including the structure optimization of the seat side panel, the center hinge, framework under the cushion and the backrest lock. The results indicated that the optimized seat improved the occupant protection performance by reducing occupant damage parameters compared with original seat, which illustrated that the optimization basically met the target.展开更多
To improve the passive safety of high-speed trains,it is very important to understand the mechanism of head injury in high-speed train collisions.In this study,the head injury mechanisms of occupants in high-speed tra...To improve the passive safety of high-speed trains,it is very important to understand the mechanism of head injury in high-speed train collisions.In this study,the head injury mechanisms of occupants in high-speed train rear-end collisions were investigated based on the occupant-seat coupling model,which included a dummy representing the Chinese 50th percentile adult male.The typical injury responses in terms of skull fractures,brain contusions,and diffuse axonal injury(DAI)were analyzed.Meanwhile,the influences of collision speed and seat parameters on head injury response were examined.The simulation results indicate that the skull fractures primarily occur at the skull base region due to excessive neck extension,while the brain contusions and DAI result from the relative displacement of different brain regions.The increase in collision speed will promote the probability of skull fracture,brain contusion,and DAI.Seat design modifications,such as reduced seat spacing,increased seat backrest angles,and selecting the appropriate cushion angle(76°)and friction coefficient(0.15),can effectively mitigate probably occupant's head injury.展开更多
基金supported by the National Natural Science Foundation of China under Grant No.51878358Natural Science Foundation of Zhejiang Province under Grant No.LY18E080012National Key Technology R&D Program of the Ministry of Science and Technology under Grant 2013BAJ10B06.
文摘Manually operated solar shades have a significant impact on indoor visual comfort.This research investigates occupants’appropriate seating position and view direction in a west-facing office cell using a previously developed shade behavior model.The non-dominant sorting genetic algorithm(NSGA-II)based Multi-objective optimization was adopted to identify the optimal and near optimal solutions.Daylight and glare index were used as two visual comfort objectives for optimization and robustness of optimization results against shade behavior uncertainty that was analyzed using statistical analysis.Results show that near optimal solutions can be used instead of the optimal one since they provide more flexibility in seating positions while maintaining almost the same visual comfort performance.And thus,the appropriate seating position considering occupants’preference is 1.5m away from the external window with two view directions near parallel to the window for west-facing office rooms.
文摘This paper used the Hyper Mesh and LS-DYNA software to establish a dummy-seat finite element simulation model. The head, chest and neck injury of the dummy were analyzed respectively in the frontal impact and rear impact. It was indicated that modification of seat was needed to meet the requirements. The simulation results showed that the original model cannot provide effective protection for the occupants and need for structural improvements. According to the simulation results of deformation and stress conditions of the seat parts, the original seat structure was improved and optimized for four improvement schemes, including the structure optimization of the seat side panel, the center hinge, framework under the cushion and the backrest lock. The results indicated that the optimized seat improved the occupant protection performance by reducing occupant damage parameters compared with original seat, which illustrated that the optimization basically met the target.
基金supported by the National Natural Science Foundation of China(Grant No.12122211)the Natural Science Foundation of Sichuan Province(Grant No.2022NSFSC0035)。
文摘To improve the passive safety of high-speed trains,it is very important to understand the mechanism of head injury in high-speed train collisions.In this study,the head injury mechanisms of occupants in high-speed train rear-end collisions were investigated based on the occupant-seat coupling model,which included a dummy representing the Chinese 50th percentile adult male.The typical injury responses in terms of skull fractures,brain contusions,and diffuse axonal injury(DAI)were analyzed.Meanwhile,the influences of collision speed and seat parameters on head injury response were examined.The simulation results indicate that the skull fractures primarily occur at the skull base region due to excessive neck extension,while the brain contusions and DAI result from the relative displacement of different brain regions.The increase in collision speed will promote the probability of skull fracture,brain contusion,and DAI.Seat design modifications,such as reduced seat spacing,increased seat backrest angles,and selecting the appropriate cushion angle(76°)and friction coefficient(0.15),can effectively mitigate probably occupant's head injury.
