舱室内爆多毁伤元载荷联合作用高效数值仿真方法

High-efficiency numerical simulation methods for combined effects of multi-damage loads in cabin internal explosions

  • 摘要:
    目的 旨在解决舱室内爆多毁伤元载荷联合作用仿真计算问题并兼顾计算精度和计算效率,提出新的接触−耦合重启动(以下简称“接触重启法”)和载荷等效加载(以下简称“等效加载法”)2种高效数值仿真方法。
    方法 接触重启法刚开始不启用破片与结构的接触设置,待破片快侵彻结构时启动;等效加载法简化考虑炸药爆轰的流固耦合过程,提取结构反射压力进行载荷的简化加载;考虑裸药内爆和炸药端部贴预制破片空爆这2种情况,验证上述2种高效数值仿真方法的合理性和准确性。与常规的全时域接触−耦合仿真方法(以下简称“全时域法”)进行对比,讨论所提方法对舱室内爆多毁伤元载荷联合作用仿真的可行性和优越性。
    结果 结果表明:相较于全时域法,在近距爆炸多毁伤元载荷联合作用仿真计算中,接触重启法不仅能保证计算精度,还可提升计算效率;等效加载法能够避免远距爆炸或大尺度舱室内爆多毁伤元载荷联合作用下网格尺寸不匹配和网格数过大等问题,极大地节省了计算资源,并兼顾了计算精度。
    结论 研究可为大尺度舱室内爆多毁伤元载荷联合作用数值仿真提供合理可行的方法。

     

    Abstract:
    Objective In order to find a numerical simulation method that can simulate the combined effects of multi-damage loads under cabin internal explosion, while considering both simulation accuracy and efficiency, this paper proposes two high-efficiency simulation methods, namely contact-coupling restart (CCR) and load equivalent loading (LEL).
    Methods In CCR, the contact setting between structures and fragments is inactive, and is activated just before the fragments penetrate the structures. The LEL method directly performs simplified loading based on empirical equations, and neglects the fluid-structure coupling process of charge detonation. The rationality and accuracy of the two proposed high-efficiency simulation methods are verified by bare-charge internal explosions and the air blasts of charges with prefabricated fragments pasted on both ends. The two high-efficiency simulation methods are then compared with the conventional whole-time contact-coupling simulation (WCC) method, and their feasibility and superiority are discussed.
    Results Compared with the WCC method, CCR can not only ensure simulation accuracy, but also greatly improve simulation efficiency in the case of the combined effects of multi-damage loads under close-range air blast. LEL can avoid the grid-size mismatching problem and excessive number of grids in the case of the combined effects of multi-damage loads under far-distance air blast or large-scale cabin internal explosion. LEL can also greatly save simulation resources and significantly enhance simulation accuracy.
    Conclusion This study can provide a reasonable and feasible method for the numerical simulation of the combined effects of multi-damage loads under cabin internal explosion.

     

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