潘騰 陳力 方秦
摘要:在結(jié)構(gòu)構(gòu)件上施加均布沖擊(爆炸)荷載一直是動力試驗領域的難題。提出了一種落錘沖擊氣囊施加均布動荷載的試驗裝置,和一個雙自由度彈簧阻尼沖擊加載簡化分析模型;給出了該模型的基本力學方程、邊界條件和求解方法,并進行了有限元驗證;建立了所提出沖擊加載試驗裝置的精細化有限元模型,分析了構(gòu)件上各受荷區(qū)域的荷載均布情況,驗證了所提出裝置的可行性。基于所建立的簡化分析模型,討論了剛度、荷載作用時間和阻尼比等關鍵參數(shù),對構(gòu)件上動荷載的影響,并給出了基本規(guī)律。計算結(jié)果表明,在選定合適的參數(shù)后,落錘沖擊氣囊試驗裝置能夠較好地模擬構(gòu)件上的均布動荷載,為實驗室中進行爆炸沖擊試驗提供了一種可能。
關鍵詞:沖擊;氣囊;均布動荷載;爆炸荷載
中圖分類號:TU317
文獻標志碼:A文章編號:16744764(2016)01012207
Abstract:
It is very difficult to apply a uniform impact (explosion) loads on the structural member in the laboratory. We presented an innovative loading apparatus using a drop hammer impacting on the airbag to simulate the uniform loads,and proposed a twoDOF (degreeoffreedom) analytical model. The fundamental mechanical equation, boundary conditions and solution method were given and verified. A fine finite element model was established and the loading effects on the divided area were compared to verify the feasibility of presented apparatus. Some key factors of the dynamic loads were also discussed, including stiffness, load duration and damping ratio.The results show that the presented apparatus can be applied to simulate the uniform dynamic loads with choosing parameters,which provides a possibility for experiments simulating blast loading in the laboratory.
Keywords:impact;airbag;uniform dynamic loads; explosion load
燃氣爆炸、恐怖襲擊等偶然性爆炸災害頻繁發(fā)生,常常造成工程結(jié)構(gòu)損傷破壞,乃至坍塌。因此,結(jié)構(gòu)構(gòu)件在爆炸荷載作用下的動力響應一直是學術(shù)界的研究熱點[14]。在常見比例爆距范圍,通常認為構(gòu)件上的爆炸荷載是均布動荷載[1],而野外爆炸試驗又有難度大、費用高的不足,所以人們一直致力于尋找一種在實驗室范圍內(nèi)模擬結(jié)構(gòu)上均布動荷載(爆炸)的試驗方法。
目前,實驗室模擬沖擊(爆炸)動荷載的裝置主要有:模爆器、爆坑、輕氣炮,SHPB和落錘等。模爆器和爆坑試驗費用高、危險性大、試驗條件苛刻,所需炸藥不易獲得,且荷載持續(xù)時間長于實際情況。……