饱和冲量及其等效方法在舱室内爆炸中的应用

Saturated impulse and application of saturation equivalent method in cabin explosion

  • 摘要:
      目的  对于受到爆炸脉冲载荷冲击作用的船体结构,基于饱和冲量现象的相关研究表明,仅根据最大载荷幅值和脉冲总冲量来设计船体结构是不合理的,需探究工程应用中的饱和冲量现象。
      方法  首先,总结饱和冲量概念的提出及研究发展;然后,以舱室内爆炸为典型算例,分析内爆炸载荷的曲线特性及结构响应特征;最后,基于饱和等效方法将复杂的内爆炸载荷等效为矩形脉冲载荷,采用理论及数值方法对等效载荷进行计算。
      结果  结果表明:在舱室内爆炸准静态超压情况下普遍存在饱和冲量现象,实际工程应用中爆炸载荷会对结构造成较大的塑性变形,通常超过10倍板厚;而运用基于饱和冲量的等效方法分析,所得结果与数值仿真结果的误差小于10%。
      结论  运用此方法可更准确地得出结构塑性动力响应结果,在结构抗冲击设计优化时,还可减少繁琐的复杂非线性数值计算,使设计更高效。

     

    Abstract:
      Objectives  For the ship structures subjected to pulse loading such as explosion or slamming, research on the "saturated impulse" phenomenon shows that designing hull structures with maximum loading amplitude and total impulse is unreasonable. Hence, exploring the application of saturated impulse in engineering is necessary.
      Methods  The concept and development of the saturation phenomenon are first summarized. Then, taking a cabin internal explosion as a typical example, the loading curve and structural response characteristics are analyzed by FEM. Following that, the complex blast loadings are equivalent to the rectangular pressure pulse loadings of the saturated equivalent method, and the response of structures under the equivalent loadings are calculated by theoretical and numerical methods.
      Results   The results show that the saturated impulse phenomenon exists in a wide array of cabin explosions due to the existence of quasi-static overpressure. In practical engineering problems, the explosion loading will produce large plastic deformation (usually more than 10 times the plate thickness), with an error of less than 10% between the analysis results and the numerical simulation results, by using the equivalent method based on saturated impulse.
      Conclusions  By studying the cabin internal explosion saturation phenomenon, the results of the plastic dynamic response of the structure can be given more accurately, and repeated complex nonlinear numerical calculations can be reduced in structural optimization, so as to carry out the anti-impact design of the hull structure more effectively.

     

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