Safety is a huge concerns with growth of leisure sports, transportation and advanced science technologies. This study was initiated to minimize head injury, which is the biggest cause of increased external activity and traffic accident injuries and deaths. Based on consumer needs, we developed a low cost airbag which can be covered with a safety helmet. The results of the survey showed that safety is the most important part of consumers'' safety helmets. It was also predicted that increasing weight would be the biggest problem due to reliability and portability.
A curved airbag cushion parts which can be attached to a helmet and a sensor parts of a block type are designed. Impact analysis was performed by specifying the pressure inside the airbag and the volume of the airbag as variables. The result were that stress distribution and displacement was focused on bottom of designed cushion airbag. It was observed that decision of safety was related to volume of cushion and stress distribution was very closed to impulse. Stress of internal helmet was followed to rigidity and material.
The analysis results obtained through questionnaire survey using judgment sampling method are as follows. The new product concept was evaluated as a product that can convey the value of safety that consumers want. In order to be developed as a consumer-oriented new product, besides safety, ease of use, design and portability must be improved together, and countermeasures to eliminate the weight increase due to air bag attachment should be taken.
Considering the results of the questionnaire, it was understood that the sensor part such as the airbag cushion part and the sensor part are designed as a block type to reduce the weight to a certain extent.
When the volume of the external air bag was 30 mm and 50 mm, the stress tended to increase slightly at the internal pressure of 140 KPa. This is due to the material properties of the helmet that fixes the airbag, which is slightly increased by the rebound characteristics of the airbag above 140 KPa.
In order to understand the deformation behavior according to the impact direction, the impact was applied to the bottom of the rear under the same conditions. As a result, the impact was reduced by 75% higher than the upper load, and the deformation was remarkably reduced. It was found to be safe for the rear and side impacts if an internal pressure of 120 KPa or more was applied to a volume of 50 mm.