Change search
CiteExportLink to record
Permanent link

Direct link
Cite
Citation style
  • apa
  • harvard1
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf
Importance of Windscreen Modelling Approach for Head Injury Prediction
KTH, School of Technology and Health (STH), Medical Engineering, Neuronic Engineering.ORCID iD: 0000-0001-7908-6270
KTH, School of Technology and Health (STH), Medical Engineering, Neuronic Engineering.ORCID iD: 0000-0003-0125-0784
2016 (English)In: 2016 IRCOBI Conference Proceedings - International Research Council on the Biomechanics of Injury, 2016Conference paper, Published paper (Refereed)
Abstract [en]

The objective of this study is to evaluate the capability of two modelling approaches in capturing  both accelerations and deformations from head impacts, and to evaluate the effect of modelling approach on  brain injury prediction. The first approach is a so‐called smeared technique, in which the properties of the two  glass  sheets and  the intermediate  polyvinyl  butyral  (PVB) are  combined and  divided into  two  coinciding  shell layers, of which one can fracture. The second approach consists of three shell layers, representing the glass and  PVB,  separated by  the  distance of  their  thickness, using a non‐local  failure criterion  to initiate  fracture in  the  glass.  The  two  modelling  approaches  are  compared  to  impact  experiments  of  flat  circular  windscreens,  measuring  deformations  and  accelerations  as  well  as  accelerations  from  impacts  against  full  vehicle  windscreens.  They  are  also  used  to  study  head‐to‐windscreen  impacts  using  a  detailed  Finite  Element  (FE)  model,  varying  velocity,  impact  direction  and  impact  point.  Only  the  non‐local  failure  model  is  able  to  adequately  capture  both  the accelerations and  deformations  of an  impactor. The FE  head model  simulations  also reveal that the choice of modelling approach has a large effect on the both localisation of the strain in the  brain and the characteristics of the strain‐time curve, with a difference in peak strain between 8% and 40%.  

Place, publisher, year, edition, pages
2016.
Keyword [en]
brain injury, fem, finite element method, head impact, pedestrian, windscreen modelling
National Category
Medical Engineering
Identifiers
URN: urn:nbn:se:kth:diva-198525Scopus ID: 2-s2.0-84996656540OAI: oai:DiVA.org:kth-198525DiVA: diva2:1057243
Conference
International Research Council on the Biomechanics of Injury, 2016
Note

QC 20161219

Available from: 2016-12-16 Created: 2016-12-16 Last updated: 2017-10-12Bibliographically approved
In thesis
1. Understanding Boundary Conditions for Brain Injury Prediction: Finite Element Analysis of Vulnerable Road Users
Open this publication in new window or tab >>Understanding Boundary Conditions for Brain Injury Prediction: Finite Element Analysis of Vulnerable Road Users
2017 (English)Doctoral thesis, comprehensive summary (Other academic)
Abstract [en]

Vulnerable road users (VRUs) are overrepresented in the statistics on severe and deadly injuries in traffic accidents, most commonly involving the head. The finite element (FE) method presents the possibility to model complex interactions between the human body and vehicles in order to better understand the injury mechanisms. While the rapid development of computer capacity has allowed for increasingly detailed FE-models, there is always a benefit of reducing the studied problem. Due to its material properties, the brain is more sensitive to rotational motion than to purely linear, resulting in complex injury causation. When studying brain injuries caused by a direct impact to the head, simulations using an isolated head model significantly increases efficiency compared to using a complete human body model. Also evaluation of head protective systems uses isolated mechanical head representations. It is not, however, established the extent to which the boundary conditions of the head determine the outcome of brain injuries.

FE models of both the entire human body and the isolated head were used in this thesis to study the effect of the body, as well as active neck muscle tension, on brain injury outcome in VRU accidents. A pediatric neck model was also developed to enable the study of age-specific effects. A vehicle windscreen model was developed to evaluate the necessity of capturing the failure deformation during pedestrian head impacts.

It was shown that the influence of the neck and body on brain injury prediction is greater in longer duration impacts, such as pedestrian head-to-windscreen impacts with an average difference of 21%. In accidents with shorter duration impacts, such as head-to-ground bicycle accidents, the average influence was between 3-12%. The influence did not consistently increase or limit the severity, and was dependent on the degree of rotation induced by the impact, as well as the mode of deformation induced in the neck. It was also shown that the predicted brain injury severity is dependent on capturing the large deformations of fractured windscreen, with the greatest effect near the windscreen frame. The pediatric neck model showed a large effect of age-dependent anatomical changes on inertial head loading, making it a promising tool to study the age-dependent effects in VRU accidents.

Place, publisher, year, edition, pages
Stockholm: KTH Royal Institute of Technology, 2017. 83 p.
Series
TRITA-STH : report, ISSN 1653-3836 ; 2017:11
Keyword
Brain injuries; Vulnerable Road Users; windscreen impacts; Finite Element Analysis; pedestrian accidents; cycling accidents; pediatric neck
National Category
Other Medical Engineering
Research subject
Applied Medical Technology
Identifiers
urn:nbn:se:kth:diva-215643 (URN)978-91-7729-568-6 (ISBN)
Public defence
2017-11-06, T2, Hälsovägen 11C, Huddinge, 10:00 (English)
Opponent
Supervisors
Note

QC 20171013

Available from: 2017-10-13 Created: 2017-10-12 Last updated: 2017-10-16Bibliographically approved

Open Access in DiVA

No full text

Other links

ScopusPublished version

Search in DiVA

By author/editor
Alvarez, Victor SKleiven, Svein
By organisation
Neuronic Engineering
Medical Engineering

Search outside of DiVA

GoogleGoogle Scholar

Total: 20 hits
CiteExportLink to record
Permanent link

Direct link
Cite
Citation style
  • apa
  • harvard1
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf