High fidelity coupling methods for blast response of thin shell structures

Abstract

Computational simulation of structures subjected to blast loads requires integration of computational shock physics and structural response with finite deformations. The authors’ particular application of interest is blast loads on thin shell structures, which often deform concurrently with the shock or pressure wave evolution over the structure. This necessitates two-way coupled algorithms. We combine state-of-the-art shock physics, structural modeling with shell finite elements, and an immersed boundary method that accommodates arbitrarily thin structures. Building on successful techniques in the literature, we focus on accuracy and convergence rates of novel extensions to time step coupling approaches and immersed boundary treatments. The new techniques are developed to easily integrate with typical, industry-standard production analysis codes. The final recommended technique combines centered-difference structural time integration, predictor–corrector fluid time integration, level set surface tracking, and the Half Riemann Immersed Boundary method. Examples are given that show robust and accurate modeling of shock and pressure wave problems, and verification problems highlight good convergence properties for both fluid and fluid–structure applications. • Fluid–structure interaction algorithms for blast loads on thin structures. • Combine shock-physics, shell finite elements, and immersed boundaries. • Explore convergence rates of time step coupling and immersed boundary treatments. • Coupling approach takes advantage of convergence rates of underlying solvers.