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.