# Blast Resistance of Confined Multilayer Graded Corrugated-Core Sandwich Cylindrical Shells

## TL;DR

Graded multilayer corrugated-core cylindrical shells improve blast resistance by up to 75% through optimized thickness and core design.

## Contribution

A new method using surrogate modeling and optimization identifies optimal thickness-graded designs for blast resistance.

## Key findings

- Inner-thick/outer-thin wall gradients reduce outer-facesheet deformation by up to 75%.
- Thickness grading outperforms height grading under blast loads.
- Optimized designs can reduce mass by ~18% or deformation by ~20%.

## Abstract

What are the main findings?
Graded multilayer corrugated-core shells enhance resistance to internal blasts..An inner-thick/outer-thin wall gradient reduces outer-facesheet deformation by up to 75%.Thickness grading performs better than height grading under the studied blast loads.Surrogate modeling with ASA optimization identifies optimal thickness distributions.

Graded multilayer corrugated-core shells enhance resistance to internal blasts..

An inner-thick/outer-thin wall gradient reduces outer-facesheet deformation by up to 75%.

Thickness grading performs better than height grading under the studied blast loads.

Surrogate modeling with ASA optimization identifies optimal thickness distributions.

What are the implications of the main findings?
Aligning core strength with blast attenuation promotes more uniform and complete layer compaction.Optimized designs can reduce mass by ~18% at a prescribed deformation limit.Alternatively, they can reduce deformation by ~20% at a prescribed mass limit.

Aligning core strength with blast attenuation promotes more uniform and complete layer compaction.

Optimized designs can reduce mass by ~18% at a prescribed deformation limit.

Alternatively, they can reduce deformation by ~20% at a prescribed mass limit.

A graded multilayer corrugated-core sandwich cylindrical shell is proposed as an innovative blast-resistant container to resist internal blast loading. The blast resistance performance of both uniform and graded multilayer corrugated shells was systematically investigated through finite element analysis. Results revealed that sandwich shells featuring an internally thick and externally thin core wall arrangement exhibited superior blast resistance. This configuration optimally aligns with the natural attenuation behavior of blast pressure, which gradually decreases from inner to outer layers during multilayer core collapse. Structures with core layer height gradients, characterized by internally high and externally low layers, also demonstrated enhanced performance under blast loading. While increasing the gradient magnitude generally improves blast resistance, this benefit diminishes with escalating blast intensity. Notably, wall-thickness-graded structures consistently outperformed height-graded configurations. Finally, a radial basis function surrogate model combined with adaptive simulated annealing optimization was employed to identify optimal thickness-graded cylindrical shell configurations tailored for either maximum blast resistance or minimum structural mass.