Numerical Dissipation and Stability Analyses of a Highly Efficient Numerical Approach Proposed for Predicting the Blast Loads from Large TNT-Equivalent Explosives on Building Structures

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An efficient CE/SE-based numerical method implemented in LS-DYNA R7.0 has been developed for predicting far-field blast loads from large TNT-equivalent explosives on structures, offering validated accuracy for engineering risk assessment. However, the stability and numerical dissipation characteristics induced by its non-physical parameters (α, β, CFL) remain unquantified, limiting optimal application. To resolve this, we analytically derived an explicit numerical dissipation term coefficient aβΔx(w+ − w−)(1 − CFL2)/4 from a simplified 1D continuity equation and established stability criteria via von Neumann analysis. Benchmark simulations of 1 kg TNT free-air bursts demonstrate that increasing α from 0.1 to 5.0 reduces peak overpressure by 13.0%, while β rising from 0.5 to 1.0 decreases it by 1.89%, and elevating CFL from 0.05 to 0.50 increases overpressure by 1.92%. Critically, stability requires α ≥ 0, 0 ≤ β ≤ 1, and 0 ≤ CFL ≤ 1. These first theoretical guidelines for non-physical parameter selection enhance the method’s prediction accuracy and computational efficiency.

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