頭盔帽殼之形狀最佳化對機車安全帽撞擊能量吸收力之影響

The Effect of Shape-Optimal in Shell of Helmet to the Energy Absorption during Motor-Helmet Impacting

李曜宏(Yao-Hung Lee)

指導教授 ： 洪興林

崑山科技大學/工程學院/機械工程研究所/碩士(2009年)

摘要

避免機車騎士頭、臉部傷害，最有效的方法就是佩戴機車頭盔。為能製造出合乎市場需求、經濟便宜且堅固耐用之機車頭盔，利用電腦模擬暸解撞擊時頭盔之動態行為是必要的。其中，頭盔帽殼因職司撞擊能量之吸收及保護頭盔避免破裂，故於機車頭盔之設計上具有關鍵的地位。
本論文探討機車頭盔帽殼表面附加肋條時，頭盔受撞擊時之防護力及吸收能量能力，並對頭盔帽殼之設計與開發提供有價值之建議。利用有限元素分析軟體(LS-DYNA)執行模擬頭盔在承受E.C.E.標準撞擊測試程序時之動態行為，並找出能保護頭盔及吸收此衝擊能量之最佳肋條外型與個數。首先，利用壓縮-拉伸實驗及電腦模擬比對法找出帽殼及頭盔墊料之材料參數。再根據電腦模擬結果，分析各種不同的肋條外型與個數承受撞擊時之頭部傷害指數(Head Injury Criterion)及最大加速度值(Peak Acceleration)。分析結果顯示：帽殼表面附加肋條對於保護頭盔及吸收衝擊能量有明顯的助益，且具備適中高度及較小寬度之單一肋條時為最佳之帽殼肋條外型與個數。因為於此狀況下，其勁度不致因過大使得頭盔與肋條接合處產生破壞且其撞擊波之遲滯效應較小，故產生之HIC及最大加速度值較小。最後，根據模擬結果得出，建議之機車頭盔肋條設計尺寸大約為10 mm，肋條寬度大約為4 mm。

關鍵字

機車頭盔 ； 帽殼肋條 ； 吸收衝擊能量最佳外型組合

並列摘要

When traffic accident occurs, the most effective method to protect motorcycle knight is to wear the helmet. With the purpose of decreasing of cost of manufacture which conform the market demand, developing more durable motorcycle helmet, accurate computer simulation is essential to the understanding of dynamic behavior of the helmet while striking. Moreover, because of the functional impact energy absorption and the prevention of helmet breaking, an effective helmets shell plays a key role in the design of motorcycle helmet.
The purpose of this thesis was to add ribs on the surface of helmet and to analyze its ability of protection and energy absorption during motor-helmet impacting. Moreover, a valuable suggestions of shell were proposed for the design and develope of motor-helmet. By using the software LS-DYNA and implementing the E.C.E. standard testing procedures, the dynamic behavior of helmet was simulated and optimal configurations of helmet shell were found including shapes and numbers of ribs Firstly, material parameters of shell and helmets liner were constructed by compression-tensile test and comparison of simulation results. Then, according to the head injury criterion (HIC) and maximum acceleration value during striking of helmet obtaining from computer simulation, the ability of dynamic energy absorption for different numbers and shapes of ribs, were evaluated. The analysis results reveal that shell rib has significantly effect to the impact energy absorption and the prevention of helmet. Furthermore, the single rib with medium height and small width are the optimal shapes and numbers of ribs. The reasons are that under the situations, the stiffness of helmet are not too hard to fail and with the help of small retarding effects of wave propagation during impact, the HIC and maximum acceleration value behave relatively small. Finally, the simulation results also reveal that the recommended height of rib and the width of it can be set as 10 and 4mm, respectively.

並列關鍵字

Motorcycle Helmet ； Shell Rib ； Absorption Impact Energy ； Optimal Shape Combination

參考文獻

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