本研究之目的在了解由長纖補強之射出成形所製造的三明治結構安全
帽在動態下的行為，並希望藉由有限元素法的分析找出最適當的貼法。我
們用CNS國家標準中機器腳踏車車用安全帽檢驗方法當中的衝擊吸收測試(
shock absorption)及耐穿透性測試(penetration resistance)對射出成
形製造的三明治結構安全帽做測試。我們使用有限元素分析軟體(ANSYS)
來研究各種不同的長纖黏貼方式對於安全帽於衝擊吸收測試時之動態應力
及衝擊加速度值的變化; 並且將結果和實驗做比較，比較結果相當接近，
顯示以有限元素分析方法來做安全帽的動態分析是合適的。由本文研究結
果，我們建議使用編織過的纖維黏貼於整個安全帽上增加其耐穿透性並使
用較厚較軟的保麗龍襯墊降低衝擊加速度。

This paper is concerned with the dynamic property of injection
molded sandwich helmet. Numerical analysis have been used to
find the proper way for fitting the long fiber with the shell.
Experimental tests, one is shock absorption , the other is
penetration resistance both in CNS standard have been performed
.Finite element code (ANSYS) is used to investigate the dynamic
stress distribution of a helmet and the change of the
acceleration by shock. Both experimental tests and numerical
analysis were checked in ordered to assure the accuracy and
consistency. The results show that the finite element method
used for dynamic impact analysis is a suitable method. We
suggest that use crossed fiber to raise the resistance of
helmet, and use lower and thicker density liners to lower the
peak acceleration.