A Numerical Study of Traumatic Brain Injury Due to Ground Impact in an SUV-Pedestrian Crash Using Full-Scale Finite Element Models

2010 ◽  
Author(s):  
Atsutaka Tamura
Keyword(s):  
Traumatic Brain Injury ◽  
Finite Element ◽  
Brain Injury ◽  
Numerical Study ◽  
Element Model ◽  
Whole Body ◽  
Impact Speed ◽  
Intrinsic Complexity ◽  
Pedestrian Crashes ◽  
Ground Impact

A number of studies have worked on traffic injuries or traumas related to pedestrian impacts. However, most of them placed more focuses on traumatic injuries due to primary impact with a striking vehicle rather than those involved in secondary impact with the ground. In this study, a validated, human whole-body, pedestrian finite element model was utilized to investigate the potential risk of traumatic brain injury (TBI) relevant to the ground impact as well as primary head strike in an SUV-to-pedestrian collision. By conducting a set of numerical experiments at impact speed of 25 and 40 km/h with pedestrian’s pre-impact, transverse, traveling speed of 1.3 m/s, it was found that ground impact is likely to cause serious TBI even in a low impact speed level. Although the post-impact kinematics and subsequent kinetics were considerably unpredictable due to the intrinsic complexity of pedestrian impact, this finding also suggests that impact speed does not necessarily contribute to the severity of pedestrian TBI involving vehicle with a higher profile. In the future, an effective countermeasure for ground impact should be taken into account to reduce the risk of sustaining serious TBIs in pedestrian crashes.

Pedestrian Accident Reconstruction Using a Human Body Finite Element Model

2015 ◽  
Author(s):  
Atsutaka Tamura ◽  
Takao Koide
Keyword(s):  
Finite Element ◽  
Numerical Experiments ◽  
Element Model ◽  
Accident Reconstruction ◽  
Fe Model ◽  
Pedestrian Accident ◽  
Intrinsic Complexity ◽  
Post Impact ◽  
Ground Impact ◽  
Kinematics And Kinetics

A series of numerical experiments were carried out using a full-scale vehicle finite element (FE) model and a validated pedestrian FE model with a detailed brain to replicate a typical, vehicle-to-pedestrian collision. We revealed that post-impact kinematics and kinetics are considerably unpredictable due to the intrinsic complexity of pedestrian crash, and ground impact rather than the primary head strike is likely to cause a serious traumatic brain injury (TBI) for struck pedestrians. We also found the importance of accounting for both translational and rotational acceleration pulses applied to the head to assess the potential risk of TBI due to eventual contact with the ground. These findings suggest that an effective countermeasure should be introduced to reduce the risk of sustaining TBIs due to secondary as well as primary head strikes even at the low-speed impact levels.

A Finite Element Model for Estimating Axonal Damage in Traumatic Brain Injury

2012 ◽  
Author(s):  
Rika M. Wright ◽  
K. T. Ramesh
Keyword(s):  
Traumatic Brain Injury ◽  
Finite Element ◽  
Brain Injury ◽  
White Matter ◽  
Finite Element Model ◽  
Axonal Injury ◽  
Diffuse Axonal Injury ◽  
Element Model ◽  
Cellular Level ◽  
The Brain

There has been an ongoing effort to reduce the occurrence of sports-related traumatic brain injury. These injuries are caused by an impact to the head and often lead to the damage of neural axons in the brain. This type of damage is classified as diffuse axonal injury (DAI) or traumatic axonal injury (TAI) [1]. One of the difficulties in studying the progression of axonal injury is that the structural signature of DAI cannot be readily visualized with conventional medical imaging modalities since the damage occurs at the cellular level [2]. This also makes the injury difficult to diagnose. Many researchers have turned to finite element (FE) models to study the development of diffuse axonal injury. FE models provide a means for observing the mechanical process of injury development from the loads to the head at the macroscale to the damage that results at the cellular level. However, for a finite element model to be a viable tool for studying DAI, the model must be able to accurately represent the behavior of the brain tissue, and it must be able to accurately predict injury. In this work, we address both of these issues in an effort to improve the material models and injury criteria used in current FE models of TBI. We represent the white matter with an anisotropic, hyper-viscoelastic constitutive model, incorporate the microstructure of the white matter through the use of diffusion tensor imaging (DTI), and estimate injury using an axonal strain injury (ASI) criterion (Figure 1). We also develop a novel method to quantify the degree of axonal damage in the fiber tracts of the brain.

Numerical Study for Global Detection of Cracks Embedded in Beams

1999 ◽  
Author(s):  
S. A. Lipsey ◽  
Y. W. Kwon
Keyword(s):  
Finite Element ◽  
Dynamic Analysis ◽  
Natural Frequency ◽  
Mode Shape ◽  
Numerical Study ◽  
Element Model ◽  
Mode Shapes ◽  
Linear Effect ◽  
Modes Of Vibration ◽  
Damage Simulation

Abstract Damage reduces the flexural stiffness of a structure, thereby altering its dynamic response, specifically the natural frequency, damping values, and the mode shapes associated with each natural frequency. Considerable effort has been put into obtaining a correlation between the changes in these parameters and the location and amount of the damage in beam structures. Most numerical research employed elements with reduced beam dimensions or material properties such as modulus of elasticity to simulate damage in the beam. This approach to damage simulation neglects the non-linear effect that a crack has on the different modes of vibration and their corresponding natural frequencies. In this paper, finite element modeling techniques are utilized to directly represent an embedded crack. The results of the dynamic analysis are then compared to the results of the dynamic analysis of the reduced modulus finite element model. Different modal parameters including both mode shape displacement and mode shape curvature are investigated to determine the most sensitive indicator of damage and its location.

Étude de la réouverture de la lagune du Havre aux Basques. I. Modélisation numérique des conditions d'écoulement

1995 ◽  
Vol 22 (1) ◽  
pp. 55-71
Author(s):  
Y. Ouellet ◽  
A. Khelifa ◽  
J.-F. Bellemare
Keyword(s):  
Finite Element ◽  
Numerical Study ◽  
Element Model ◽  
Two Dimensional ◽  
Flow Conditions ◽  
Modélisation Numérique ◽  
Tidal Flows ◽  
Dimensional Finite Element ◽  
The Stability ◽  
La Madeleine

A numerical study based on a two-dimensional finite element model has been conducted to analyze flow conditions associated with different possible designs for the reopening of Havre aux Basques lagoon, located in Îles de la Madeleine, in the middle of the Gulf of St. Lawrence. More specifically, the study has been done to better define the depth and geometry of the future channel as well as its orientation with regard to tidal flows within the inlet and the lagoon. Results obtained from the model have been compared and analyzed to put forward some recommendations about choice of a design insuring the stability of the inlet with tidal flows. Key words: numerical model, finite element, lagoon, reopening, Havre aux Basques, Îles de la Madeleine.

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