空間高度對球面網殼結構內爆炸響應的影響

高軒能++付詩琪

摘要：

基于修正后的JohnsonCook材料模型，應用ANSYS/LSDYNA建立K8型單層球面網殼計算模型，對內爆炸下不同空間高度的結構爆炸響應進行計算和分析。首先，分析結構內爆炸沖擊波傳播規律，驗證模型參數選取的可行性；其次，討論內爆炸作用下球面網殼的動力響應，對比分析不同本構模型對爆炸響應的影響；最后，定義下部支承結構所圍體積占結構所圍總體積的比值為空間高度系數，討論空間高度系數對墻面未開洞和墻面開洞球面網殼動力響應的影響。結果表明，爆炸沖擊波在球面網殼結構角部有匯聚效應，與反射沖擊波共同作用，嚴重影響球面網殼結構的動力響應；對于墻面未開洞的球面網殼，爆炸響應受反射沖擊波影響較大；對于墻面開洞的球面網殼，爆炸響應受空間高度系數影響較大?；谘芯拷Y果給出了球面網殼結構在內爆炸下防爆和抗爆設計的合理空間高度系數建議值。

關鍵詞：

球面網殼；內爆炸；空間高度；動力響應；沖擊荷載

Abstract：

Based on the modified JohnsonCook material model， ANSYS / LSDYNA was used to establish the model of K8 singlelayer spherical reticulated shell， and the structural explosion responses were calculated and analyzed with different space heights. Firstly， the propagation law of the shock waves inside the structure was analyzed，and the feasibility of parameters selection was verified. Secondly， the dynamic responses of the spherical reticulated shell under the internal explosion were discussed， and the influence of different constitutive models on the explosion responses was comparative analyzed. Finally， the ratio of the volume enclosed by lower supporting structure to the total volume surrounded by the whole structure was defined as a space height coefficient. The influence of the space height coefficient on the dynamic responses of spherical latticed shell （with or without holes on wall） was studied and discussed. The results show that the shock waves have a converging effect at the corner of the spherical shell structure， combined with the reflected shock waves， which may seriously affect the dynamic responses of the spherical shell. For the spherical shell with wall no openings， the explosion responses were greatly affected by the reflected shock wave， and for the spherical shell with wall openings， the explosion responses were greatly affected by the space height coefficient. Based on the research results， the reasonable space height coefficient of explosionresistant design on spherical shell structure under internal explosion was proposed.

Keywords：

spherical reticulated shell； internal explosion； space height； dynamic response； impact load

單層球面網殼結構是一種典型的空間結構，多用于地標性建筑。此類建筑通常人員密集，一旦受到爆炸襲擊，將造成極為惡劣的社會影響，故研究大空間結構在內爆炸作用下的動力響應，對于結構抗爆設計具有重要的工程價值[1]。

爆炸沖擊荷載是典型的動力荷載，具有作用時間短、峰值大的特點，建筑結構在爆炸沖擊荷載作用下的結構響應十分復雜。高軒能等[25]建立鋼網殼結構數值計算模型，運用POD法分解鋼網殼內表面的沖擊波超壓，解決了沖擊波荷載的時空差異性，進而對單層球面鋼網殼在內爆炸作用下的動力響應進行了數值模擬計算，探索了不同參數變化對結構動力響應的影響。……