接触爆炸作用下舰船箱型梁结构的止裂效应仿真分析

Numerical Analysis of the Anti-Crack Effect of Warship Box-Girder Structures Subjected to Contact Explosion

为研究箱型梁在舰船结构抗爆中的止裂效应,首先通过模型试验分析不同加筋对板架破口大小和裂纹扩展的影响,然后在此基础上,利用商用有限元程序MSC/Dytran对舰船箱型梁结构的抗爆止裂效果进行仿真分析。结果表明,在接触爆炸下,板架的强力构件(如特大筋)对破口大小和裂纹扩展能起到很好的限制作用;通过将模型数值计算与试验结果进行比较,验证了应用程序和计算模型参数的稳定性与可靠性;箱型梁在舰船结构抗爆中能起到很好的止裂效果,这是由于一方面箱型梁的存在对甲板边板和舷侧顶板以及两者之间的连接进行了加强,减小了甲板和舷侧外板连接处的应力,另一方面,作为舰船整体结构的强力构件,箱型梁本身就能有效阻止破口及其裂纹的扩展,从而大大降低舰船结构整体的毁伤程度。

In order to investigate the anti-crack effect of box girders in warship structures, model experi- ments are conducted to examine the crevasse size and crack extension under different stiffener conditions. Based on the experiment results, the anti-crack effect of warship box girders subjected to the contact explo- sion is simulated using the commercial FEM code MSC/Dytran. The comparison between the simulation da- ta and experiments data successfully validates the proposed method. Both results show that the strength structural components （such as king-sized stiffeners） can well restrict the sizes of crevasses and the exten- sion of cracks, and good anti-crack performance of box girders are observed in the process of anti-explo- sion. On the one hand, the existence of the box girder reinforces the deck stringer and upper shipboard as well as the connections between the two, which significantly absorbs the connection stresses. On the other hand, being a strength structural component itself, the box girder efficiently restrains the extension of cre- vasses and cracks, so that the damage degree of the whole warship structure can be greatly reduced.