The role of a composite polycarbonate-aerogel face shield in protecting the human brain from blast-induced injury: A fluid–structure interaction (FSI) study

2017 ◽  
Vol 21 (7) ◽  
pp. 2484-2511 ◽  
Author(s):  
Kwong Ming Tse ◽  
Long Bin Tan ◽  
Mohamad Ali Bin Sapingi ◽  
Melanie Franklyn ◽  
Peter Vee Sin Lee ◽  
...  

Background Blast-induced traumatic brain injury is the most prevalent injury sustained by combat soldiers at the frontline. The current study aims to investigate the effectiveness of composite polycarbonate-aerogel face shields with different configurations in mitigating blast-induced brain injuries. Method A series of dynamic fluid–structure interaction simulations of a helmeted head subjected to a frontal free field blast was performed, to evaluate the effectiveness of the current conventional polycarbonate face shield and three other composite face shields with different configurations when exposed to a frontal free-field blast. Results The simulation results demonstrated that the sandwiched structured face shields of polycarbonate and aerogel provided superior blast attenuation than a single-layered polycarbonate face shield. The alternate multi-layered transparent materials of high and low densities provided the best attenuation of blast pressure transmission to the head, with the polycarbonate exterior shell casing contributing to the structural integrity of the face shield, while the lower dense aerogel filler providing high acoustic impedance to blast wave transmission. Conclusion This study provides further insights on future development and design of personal protective equipment in mitigating blast-induced injuries to the head.

Fluids ◽  
2021 ◽  
Vol 6 (3) ◽  
pp. 95
Author(s):  
Stéphane Vincent ◽  
Jean-Paul Caltagirone

The unification of the laws of fluid and solid mechanics is achieved on the basis of the concepts of discrete mechanics and the principles of equivalence and relativity, but also the Helmholtz–Hodge decomposition where a vector is written as the sum of divergence-free and curl-free components. The derived equation of motion translates the conservation of acceleration over a segment, that of the intrinsic acceleration of the material medium and the sum of the accelerations applied to it. The scalar and vector potentials of the acceleration, which are the compression and shear energies, give the discrete equation of motion the role of conservation law for total mechanical energy. Velocity and displacement are obtained using an incremental time process from acceleration. After a description of the main stages of the derivation of the equation of motion, unique for the fluid and the solid, the cases of couplings in simple shear and uniaxial compression of two media, fluid and solid, make it possible to show the role of discrete operators and to find the theoretical results. The application of the formulation is then extended to a classical validation case in fluid–structure interaction.


2009 ◽  
Vol 46 (1) ◽  
pp. 43-52 ◽  
Author(s):  
Ryo Torii ◽  
Marie Oshima ◽  
Toshio Kobayashi ◽  
Kiyoshi Takagi ◽  
Tayfun E. Tezduyar

2019 ◽  
Vol 142 (4) ◽  
Author(s):  
Srinivas Swaroop Kolla ◽  
Ram S. Mohan ◽  
Ovadia Shoham

Abstract The gas-liquid cylindrical cyclone (GLCC©, The University of Tulsa, 1994) is a simple, compact, and low-cost separator, which provides an economically attractive alternative to conventional gravity-based separators over a wide range of applications. The GLCC© inlet section design is a key parameter, which is crucial for its performance and proper operation. An in-depth evaluation of specific design modifications and their effect on safety and structural robustness are carried out in this study using finite element analysis (FEA). Fluid–structure interaction (FSI) analysis is also carried out using the results of computational fluid dynamics (CFD) aimed at investigating the effect of fluid flow on the inlet section structural integrity. The selected design modifications are based on feasibility of GLCC© manufacturing and assembly for field applications. Different case studies incorporating sustained GLCC© internal pressure, dead weight loading, forces generated because of slug flow and high temperatures are analyzed and presented in this paper. The concept of holes cut out in baffle has been effective with no stresses or deformation in the baffle area. FSI simulation of slug flow has proved that FEA direct loading case studies are far more conservative.


2019 ◽  
Vol 92 (2) ◽  
pp. 129-147 ◽  
Author(s):  
Andrea La Spina ◽  
Christiane Förster ◽  
Martin Kronbichler ◽  
Wolfgang A. Wall

2010 ◽  
Vol 19 (3) ◽  
pp. 096369351001900
Author(s):  
G. Mohamed ◽  
C. Soutis ◽  
A. Hodzic

A numerical study into the dynamic behaviour of hybrid pressurised barrels manufactured from GLARE (Glass fibre Reinforced laminate) has been performed using the Arbitrary-Lagrangian-Eulerian (ALE) method that accounts for fluid structure interaction within the explicit finite element software RADIOSS. The results high-lighted the importance of the geometrical features of the closed barrel when assessing the shock wave propagation of the blast wave. Also the effect of pre-pressurisation was studied which proved significant in providing additional internal energy to the system. It was concluded that pressurisation should be accounted in all future studies to model the dynamic crack growth and structural integrity of typical aircraft structures subjected to blast.


CFD letters ◽  
2020 ◽  
Vol 12 (12) ◽  
pp. 115-136
Author(s):  
Hedy Soon Keey Tiew ◽  
Ming Wei Lee ◽  
Wei Shyang Chang ◽  
Mohammad Hafifi Hafiz Ishak ◽  
Farzad Ismail

To achieve high fuel efficiency, vehicles designs are inclined to choose lightweight materials and structures. However, these structures are generally weak, and structural integrity is a common concern. The purpose of this paper is to carry out fluid-structure interaction (FSI) study in one-way coupling analysis on a Shell Eco Marathon (SEM) prototype car which travels in a low-speed range to analyse its structural response. A new set of economical materials is proposed and analysed with the concern on self-fabrication process. The Flax fibre composite is introduced as a part of the proposed material set due to its environmental and economic advantages. The study herein is purely a numerical simulation work as a first approach to design a sustainable SEM prototype car. The fully assembled SEM prototype car was analysed with the proposed materials with ANSYS Workbench in the coupling of the fluid (ANSYS Fluent) and structural solver (ANSYS Mechanical) in a one-way FSI. Even with a thin shell design, the proposed material only experiences minimum deformations. The simulations also reveal that the maximum von-Mises stress experienced, after considered the safety factor, is still several order lower than the yield strength. This study has confirmed that the car design has fulfilled its structural requirements to operate at the design speed.


Author(s):  
Srinivas Swaroop Kolla ◽  
Ram S. Mohan ◽  
Ovadia Shoham

The Gas-Liquid Cylindrical Cyclone (GLCC©1) is a simple, compact and low-cost separator, which provides an economically attractive alternative to conventional gravity based separators over a wide range of applications. The GLCC© inlet section design is a key parameter, which is crucial for its performance and proper operation. An in-depth evaluation of specific design modifications and their effectiveness on safety and structural robustness are carried out in this study using Finite Element Analysis. Fluid-Structure Interaction (FSI) analysis is also carried out utilizing the results of Computational Fluid Dynamics (CFD) aimed at investigating the effect of fluid flow on the inlet section structural integrity. The selected design modifications are based on feasibility of GLCC© manufacturing and assembly for field applications. Different case studies incorporating sustained GLCC© internal pressure, dead weight loading, forces generated because of slug flow and high temperatures are evaluated and presented. The concept of holes cutout in baffle have been proven effective with no stresses or deformation in the baffle area. FSI simulation of slug flow have proved that FEA direct loading case studies are far more conservative.


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