基于相似原则设计了全封闭对称结构船体梁模型,将TNT炸药置于模型中部正下方爆炸,通过改变爆距和药量来研究梁模型在水下近距非接触爆炸作用下的整体损伤特性,比较爆炸气泡运动对梁结构造成的中垂和中拱弯曲损伤作用,探索近距条件下炸药爆炸造成梁发生整体损伤变形时的高效攻击方式.研究发现:在近距非接触爆炸作用下,当爆炸气泡脉动频率与梁一阶湿频率相近时,水下爆炸气泡对梁结构造成的损伤作用以中垂弯曲为主,且爆径比越小,中垂损伤作用越明显;若爆径比不变,随着药量的增大,梁的整体损伤模式会由中垂弯曲向中拱弯曲转变;一定爆距范围内,炸药在远距离多次爆炸比近距离一次爆炸所造成的梁结构中垂损伤变形要大.%In order to investigate the damage modes of warship subjected to the non-contact underwater ex-plosions in near-field, a type of axisymmetrical ship-like beam was designed basing on similarity criterion, manufactured and tested. Dynamic responses of the beam model floating freely on water were explored by changing stand-off and amount of explosive where TNT charge was located closely under the mid-span of the model. A series of comparative tests were carried out to comprehend the damage effect of sagging or hogging caused by explosion bubbles, and look for an efficient attack way aiming for making the severest damage on ship hull. The experimental results show that underwater non-contact explosion bubble will mainly make ship-like beam damaged into sagging condition instead of hogging when the first wet fre-quency of the beam is approximate to the frequency of bubble pulse. The less the ratio of stand-off to maxi-mum bubble radius is, more possibly the sagging damage mode appears. If the ratio is unchanged, with adding the amount of explosive, the damage mode of beam will shift from sagging to hogging. Compared withone explosion attack happened in near-field, the sagging plastic deformation of beam is greater when it is subjected to twice explosions in the farer distance. Certainly, it is true where explosive is located in partic-ular range.
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