冰碰载荷下船体板弹塑性动力响应分析

Elastic-plastic responses of ship plates under ice impact loading

  • 摘要:
      目的  北极航道在远洋运输中发挥着越来越重要的作用。极地船舶在北极航行过程中不可避免地会与浮冰发生碰撞,从而使结构产生塑性变形损伤,严重影响船舶的航行安全。为了研究浮冰碰撞载荷作用下船体板所产生的塑性变形损伤和能量吸收情况,开展楔形冰与船体板碰撞模型实验研究。
      方法  首先,分析船体板的塑性变形损伤以及冰体破碎失效情况;然后,总结并对比现有不同冰体材料模型下冰撞刚性墙的计算结果,揭示不同冰材料模型下计算结果的差异;最后,采用数值模拟方法研究冰碰撞载荷作用下固支矩形板的塑性变形和碰撞力时间历程,并与模型实验结果进行对比验证。
      结果  结果显示,不同冰体材料模型的数值模拟结果其差异性和离散性较大;采用了各向同性弹脆性冰数值材料的计算模型其数值计算结果与实验结果吻合较好;在碰撞条件相同冰体与刚体碰撞时,冰体碰撞下船体板的最终塑性变形值和能量吸收值比刚体碰撞下的小。
      结论  研究成果可为极地船舶结构安全评估方法提供参考建议。

     

    Abstract:
      Objectives   Arctic channel plays an increasingly significant role in ocean transportation. Polar ships inevitably encounter ice floe impacts in the Arctic channel. These impacts may cause some permanent structural deformations, which will result in some negative effects on their work performance. Therefore, to study the plastic deformation damage and energy absorption of the plate under ice impact loading, laboratory scale impact tests between the rectangular plate and freshwater ice wedges were performed.
      Methods   The plastic deformation damage and ice failure process were obtained from ice impact tests. Also, a digital simulation for a conically shaped iceberg colliding with a rigid wall is performed based on some existing ice models. The differences in results calculated by these ice models are analyzed. Based on the digital method, the plastic deformations and time history of impact force of clamped plates under ice impact are studied in this paper, which is validated with the test results.
      Results   The results show that the results calculated by these existing ice models have large differences, and the digital results using the isotropic elastic failure ice model are compared well with the test results. The plastic deformations and energy absorptions of the plates under ice impact are smaller than those of rigid indenter impacts in the same impact conditions.
      Conclusions  These works can provide valuable information for the safety assessment of polar ship structures.

     

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