PURPOSES : Unlike European standards, domestic performance assessment standards for truck mounted attenuators (TMAs) was first stipulated in 2014 using the NCHRP Report 350 of 1993 as the standard instead of the 2009 MASH of the United States. The purpose of this study is to present an improvement in the domestic performance evaluation criteria for TMAs.. METHODS : Considering the latest TMA performance evaluation standards in the U.S. and Europe, domestic performance evaluation criteria must improve stipulations related to impact speeds, impact conditions, impact cars, and support trucks. The performance change in the TMAs according to the variation in the impact speed, impact condition, impact vehicle, and support vehicle was investigated using finite element analysis (FEA). RESULTS : The TMA for an impact speed of 100 km/h showed a limit to the safety of the occupants of the collision vehicle and workers on the road for a collision speed of 120 km/h. The safety of the workers on the road was also not guaranteed for the collision of the remaining 73.8% of vehicles that exceeds the maximum impact car weight of 1,300 kg, the lower 26.2% of the total mass composition of domestic passenger cars. In addition, a TMA that satisfied only the conditions under which the vehicle was hit head-on to the center of the TMA did not reduce the risk of a secondary collision of the impact vehicle. Furthermore, the safety of workers on the road was not guaranteed when a travel distance of a support truck of 10 tons or more was applied to a work vehicle of less than 10 tons. CONCLUSIONS : To improve the safety of road traffic, a performance level corresponding to an impact speed of 120 km/h was added to the domestic TMA performance evaluation standard, and the eccentricity and oblique collision conditions were mandatory. Furthermore, the maximum impact vehicle weight of 1300 kg was raised to 2000 kg, and the test requester had to present support trucks of lower and upper weights such that TMA mounting trucks of various weights could be used.

안전모는 낙하, 비례물에 대한 두부를 보호하는 보호구로 낙하물의 충격을 일부 흡수하여 완화시켜주는 기능을 하고 있다. 안전모 충격 흡수 성능으로 최고전달충격력이 있으나 낮을수록 성능이 좋은 것으로 나타나지만 안전모 제조과정에서 얼마 만큼의 충격이 흡수되는지는 알 수 없었다. 이로 인하여 성능 향상을 위한 충격력의 명확한 제어 가능한 성능 향상의 기준을 잡는데 어려움이 있었다. 본 연구에서는 충격량과 연관된 반발계수로 충격흡수 성능의 정도를 찾고자 하였다. 연구 대상은 시중에서 주로 착용되고 있는 ABS 재질의 안전인증 합격품을 대상으로 선정 하였다. 연구 방법으로는 운동량과 충격량의 이론으로 안전모 충격흡수성능 시험장치를 활용하여 인두에 전달된 충격량을 활용하여 충격흡수시의 반발계수를 구하고, 충격을 흡수치 않을 때를 가정하여 추정 충격력 곡선을 유도하고 충격흡수 전의 추정 최고 전달충격력과 반발계수를 구하여 충격흡수의 성능을 나타내었다. 연구결과 국내 안전인증 H사의 안전모의 최고전달충격력은 4100 N 이였고, 충격흡수 성능은 400 N 으로 약 9 %를 흡수되는 것으로 나타났다.

Recently, the velocity of vehicle in highway has been increased due to improved driving environment. Unfortunately, the impact resistance of present concrete median barrier is not enough for increased impact severity due to increased velocity, furthermore, these increased velocity occurs another secondary accidents due to the concrete fragmentation. Therefore, in this study, the evaluation of impact resistance for developed concrete median barrier was performed with shock absorber.