汽車為我國非常普及的交通工具，其所具有之安全性能對乘客來說非常重要，當發生車禍時，人體往往會因為急煞或其他原因與車內物發生撞擊導致受傷，而人體頭部是最容易撞擊到車內物也是最脆弱的部位，其中又以汽車儀表板為最容易撞擊到之區域，因此儀表板的安全性能就顯得非常重要。本研究以副駕駛座乘客為研究對象，對頭部撞擊汽車儀表板之衝擊情形進行有限元素動力學分析，由分析結果取得頭部加速度響應後即以ECE R21(Economic Commission for Europe Regulation 21)作為傷害標準，並評估撞擊之儀表板是否具有安全性，若未達ECE R21之安全標準則進行儀表板之安全性能改善。本研究將以自製頭模撞擊器進行頭模低速衝擊實驗，並與相同環境設定下之有限元素分析模擬結果進行驗證，於驗證完成後再以ECE R21所規範之頭模撞擊速度作為初始條件進行頭模高速衝擊模擬，最後由模擬之頭模加速度響應結果進行儀表板之安全性評估，結果顯示，本研究所選定之現行車儀表板在高速衝擊下於各撞擊點均符合ECE R21安全規範。當儀表板不符合安全規範時，為了降低人體頭部撞擊汽車儀表板之傷害，本研究以3D拓樸最佳化方法對儀表板之撞擊區域進行厚度設計，並在頭部撞擊儀表板時之最大位移處，以最大化其輸出位移為目標進行拓樸最佳化，最後將不同目標體積之拓樸結果應用於有限元素分析中，其結果顯示，經拓樸最佳化之汽車儀表板均具有提高頭部安全性之效果。

Head impact protection is one of the major criteria for occupant safety. This study presents the numerical and experimental interior head impact analysis of automotive instrument panel according to the United Nations Economic Commission for Europe Regulation 21 (ECE R21). To minimize the possible injury risk for unrestrained front seat passengers due to the interior head impact with the instrument panel, the panel design needs to meet the ECE R21 standard which defines a pendulum-type head form as the impactor. In this study, a numerical model based on the explicit dynamic finite element analysis (FEA) by using the commercial FEA solver, LS-DYNA, is developed. To minimize the experimental cost, a gravity-based impactor with a smaller impact speed is developed as the test apparatus for pendulum impactor in longitudinal plane (PILP) for verification purpose. The simulated results agree well with the experimental data; the average accuracy for the maximum acceleration at the head form is 95.78%. After the verification, the standard test conditions with higher impact speed are performed to evaluate the design of the instrument panel. The 3D topology optimization technique is also used to optimize the instrument panel; the objective function is to maximize the output displacement. The results show that the proposed topology optimized design can reduce the maximum acceleration of the head form during the impact.

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