防爆門受衝擊荷載之數值分析

Numerical Analysis of Blastdoor Under Impact Loading

陳宗湧(Tzong-Yong Chen)

指導教授 ： 翁宗賢

國立臺灣大學/工學院/應用力學研究所/碩士(2008年)

https://doi.org/10.6342/NTU.2008.01736

摘要

防爆門為多層強韌結構，具備耐衝擊、抗炸、防火、防彈等性能，應用於國防、高科技工業、民生安全場所等區域。本文根據一新設計之防爆門，以承受重51 lb (23 kg) 的TNT裸藥在距離6公尺處爆炸時，產生10 bar的爆炸壓力衝擊。本研究運用Pro/E繪圖軟體建構防爆門的幾何模型，再經由ANSYS有限元素分析軟體進行元素分割、材料設定，並依據美軍TM5-1300手冊設定邊界爆壓，並藉由LS-DYNA求解器計算與分析其結果數值，以了解防爆門受到爆壓衝擊時的暫態響應行為與破壞產生的模式。
數值摹擬首先進行網格獨立性測試，以確定數值解的可靠性，並由數值解的差異性，了解網格劃分密度的合適度。由分析防爆門受衝擊的模擬結果得知：在10 bar的爆壓衝擊下，顯示整體的門扇不會有破壞穿孔，門扇未脫離固定鉸鏈與門樘。但門扇中心骨架有明顯的超過材料的極限強度，若改以強度較高的I型樑結構，則應力強度與變型量均有所改善。門扇外包框和外側補強骨料鍍鋅鋼板應力破壞較大的區域，應給予適當的補強。雖然增加門扇外側補強骨料鍍鋅鋼板的厚度，對其結構強度會增強，但厚度在增加到一定的值之後，對其整體結構強度的增加效率就不是很高，所以我們可以考慮在符合其經濟成本和門扇的安全度两者之間找到一個理想的平衡點。

關鍵字

防爆門 ； 衝擊摹擬

並列摘要

The blast door is a multi-layer structure capable of impact resistance, fire resistance, and bullet resistance. It has been widely applied in national defense, high technology industry, life safety, and so on. The specially designed blast door which can stand 10 bar explosion pressure shock, as a result of 51 lb (23kg) TNT exploding at a distance of 6m, was investigated numerically in this thesis.
This research adapted the software Pro/E to build up the geometry model of the blast door and exported the model frame to the simulation software ANSYS/LS- DYNA for the setup of element mesh and material properties. Then the boundary condition parameters were set by following the U.S. Army Technical Manual TM5- 1300. Finally, the results were obtained by executing the LS-DYNA solver. By such steps mentioned above one can explore the transient response and the destruction mode of the blast door subjected to the blast pressure shock.
The grid independency was also checked to confirm the reliability of the numerical results in prior. The simulation results dictates that there is no fatal destruction in the whole assembly of the blast door under the attack of 10 bar explosion pressure shock.
The numerical works show that the anti-blast plate will not be torn from the hinges and latch. However, the central frame of the blast door displays obviously deformation and exceeds the ultimate strength of the material. As the square member of central frame of the blast door replaced by I-beam of the same cross-sectional area, the stress and deformation of the blast door are both improved. The outer rib of the blast door could be appropriately strengthened by increasing the thickness of the iron plate coated with zinc. But the improvement will be degraded as the thickness of the plate reaches some values. There is a trade off between the strength of pressure shock resistance and cost of the blast door. Anyhow, dynamic simulation provides a valuable tool to explore the performance of a blast door under shock impact at a very low cost.

並列關鍵字

blast door ； impact simulation ； LS-DYNA ； ANSYS

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