Head Injury in Facial Impact—A Finite Element Analysis of Helmet Chin Bar Performance

2000 ◽  
Vol 122 (6) ◽  
pp. 640-646 ◽  
Author(s):  
Chih-Han Chang ◽  
Li-Tung Chang ◽  
Guan-Liang Chang ◽  
Shyh-Chour Huang ◽  
Chiou-Hua Wang
Keyword(s):  
Finite Element ◽  
Head Injury ◽  
Head Injuries ◽  
Element Analysis ◽  
Maximum Acceleration ◽  
Explicit Finite Element ◽  
Motorcycle Helmet ◽  
Energy Absorbing ◽  
Protective Performance ◽  
The Impact

The chin bar of a motorcycle helmet protects the rider from facial and head injuries. To evaluate the protective performance of chin bars against head injuries from facial impacts, an explicit finite element method was used to simulate the Snell Memorial Foundation test and a proposed drop test. The maximum acceleration and Head Injury Criterion (HIC) were employed to assess the impact-absorbing capability of the chin bar. The results showed that the proposed approach should be more practical than the Snell test, and provided more information for improving the chin bar design to protect against head injuries. The shell stiffness was important in determining the protective ability of the chin bar, but a chin bar with only an outer shell and comfort foam offered inadequate protection. An energy-absorbing liner was essential to increase the protective performance of the chin bar and the liner density should be denser than that used in the cranial portion of the helmet. For the chin bar with energy-absorbing liner, a shell design that is less stiff would provide better protection. [S0148-0731(00)01206-1]

scholarly journals Finite Element Analysis of the Motorcycle Helmet Material against Impact Velocity

2021 ◽  
Vol 9 (9) ◽  
pp. 979-995
Author(s):  
Arnav Gupta
Keyword(s):  
Finite Element ◽  
Head Injury ◽  
Impact Velocity ◽  
Head Injuries ◽  
Dynamic Responses ◽  
Element Analysis ◽  
Explicit Finite Element ◽  
Injury Criteria ◽  
Motorcycle Helmet ◽  
Head Injury Criteria

Abstract: A motorcycle helmet is the best protective headgear for the prevention of head injuries due to direct cranial impact. A finite element model based on realistic geometric features of a motorcycle helmet is established, and explicit finite element code is employed to simulate dynamic responses at different impact velocities. Peak acceleration and Head injury criterion values derived from the head form are used to assess the protective performance of the helmet. We have concluded that the dynamic responses of the helmet dramatically vary with impact velocity, as well as the mechanical properties of the outer shell and energy- absorbing liner. At low velocities e.g. 8.3 m/s, the shell stiffness and liner density should be relatively low to diminish head- contact force. At high velocity e.g. 11m/s, a stiffer shell and denser liner offer superior protection against head injuries. Different tests were performed in ansys explicit dynamics solver by taking different materials and calculating PLA, Head Injury Criteria, K.E, P.E, contact energy etc. The results obtained for different materials were then compared with easy other to draw the necessary conclusion’s. Keywords: Peak Linear Acceleration (PLA), Head Injury Criteria.

FINITE ELEMENT ANALYSIS OF HONEYCOMB IMPACT ATTENUATOR

2008 ◽  
Vol 22 (09n11) ◽  
pp. 1417-1422
Author(s):  
SEUNG-YONG YANG ◽  
SEUNG-KYU CHOI ◽  
NOHYU KIM
Keyword(s):  
Finite Element ◽  
Rigid Wall ◽  
Honeycomb Structure ◽  
Student Group ◽  
Safety Requirement ◽  
Element Analysis ◽  
Explicit Finite Element ◽  
University Of Technology ◽  
Deformation Behaviors ◽  
The Impact

To participate in Student Formula Society of Automotive Engineers (SAE) competitions, it is necessary to build an impact attenuator that would give an average deceleration not to exceed 20g when it runs into a rigid wall. Students can use numerical simulations or experimental test data to show that their car satisfies this safety requirement. A student group to study formula cars at the Korea University of Technology and Education has designed a vehicle to take part in a SAE competition, and a honeycomb structure was adopted as the impact attenuator. In this paper, finite element calculations were carried out to investigate the dynamic behavior of the honeycomb attenuator. Deceleration and deformation behaviors were studied. Effect of the yield strength was checked by comparing the numerical results. ABAQUS/Explicit finite element code was used.

scholarly journals Medical Cost and Motorcycle Helmet Law in Taiwan

2012 ◽  
Vol 2012 ◽  
pp. 1-8
Author(s):  
Chin-Shyan Chen ◽  
Tsai-Ching Liu
Keyword(s):  
Head Injury ◽  
Medical Cost ◽  
Head Injuries ◽  
Population Based ◽  
Positive Influence ◽  
Hospital Length ◽  
Hospital Length Of Stay ◽  
Helmet Use ◽  
Motorcycle Helmet ◽  
The Impact

The objective of this study was to examine whether the implementation of the helmet law had reduced the likelihood of head injury and the associated medical cost in Taiwan. Data were taken from the 1996 and 1998 population-based data. In total, 888,179 and 921,058 effective samples were used in the study from the two years. Two different types of regression model were adopted to evaluate the impact of the motorcycle helmet use law on incidences of head injury and associated medical cost and hospital length of stay. The results reveal that medical cost is down by 11.5 percent and hospital LOS has fallen by 18.58 percent. Thus, with the introduction of the motorcycle helmet use law having had a demonstrably positive influence on motorcycle head injuries and fatalities, significant savings are clearly being achieved, not only in terms of economic and social costs, but also with regard to medical cost.

Agricultural aircraft wing slat tolerance for bird strike

2017 ◽  
Vol 89 (4) ◽  
pp. 590-598 ◽  
Author(s):  
Adam Deskiewicz ◽  
Rafał Perz
Keyword(s):  
Finite Element ◽  
Impact Velocity ◽  
Structural Response ◽  
Element Model ◽  
Bird Strike ◽  
Element Analysis ◽  
Content Type ◽  
Explicit Finite Element ◽  
Explicit Finite Element Analysis ◽  
The Impact

Purpose The aim of this study is to assess and describe possible consequences of a bird strike on a Polish-designed PZL-106 Kruk agricultural aircraft. Due to its susceptibility to such events, a wing slat has been chosen for analysis. Design/methodology/approach Smooth particle hydrodynamics (SPH) formulation has been used for generation of the bird finite element model. The simulations were performed by the LS-Dyna explicit finite element analysis software. Several test cases have been analysed with differing parameters such as impact velocity, initial velocity vector direction, place of impact and bird mass. Findings Results of this study reveal that the structure remains safe after an impact at the velocity of 25 m/s. The influence of bird mass on slat damage is clearly observable when the impact velocity rises to 60 m/s. Another important finding was that in each case where the part did not withstand the applied load, it was the lug where first failure occurred. Some of the analysed cases indicated the possibility a consequent wing box damage. Practical implications This finding provides the manufacturer an important insight into the behaviour of the slat and suggests that more detailed analysis of the current lug design might improve the safety of the structure. Originality/value Even though similar analyses have been performed, they tended to focus on large transport aircraft components. This investigation will enhance our understanding of structural response of small, low-speed aircraft to a bird impact, which is a realistic scenario for the chosen case of an agricultural plane.

scholarly journals Measured Impact

2018 ◽  
Vol 140 (01) ◽  
pp. 42-45
Author(s):  
James G. Skakoon
Keyword(s):  
Finite Element ◽  
Corpus Callosum ◽  
Degrees Of Freedom ◽  
Head Injuries ◽  
Analysis Model ◽  
Element Analysis ◽  
Falx Cerebri ◽  
Institute Of Technology ◽  
The Impact ◽  
The Brain

This article focuses on an innovative methodology developed by researchers at Stanford University. The new way of measuring the forces that cause head injuries aim to change how engineers protect professional and weekend athletes. By embedding both accelerometers and gyroscopes within the mouth guards, the laboratory tracked all six degrees of freedom and slashed data errors to 10 percent or less. According to one of the developer, since the upper teeth are firmly coupled to the bones of the cranium, the mouthguards can provide data accurate enough for the lab to use in finite element models to describe what is happening inside the brain. The team input the incident’s kinematics data into a finite element analysis model of the brain developed by the KTH Royal Institute of Technology in Sweden. This enabled them to simulate how different structures within the brain responded to the impact. The computer simulation showed that the falx cerebri appears to be the culprit. It is a rigid vertical sheet that separates the brain’s two lobes. It lies right above the corpus callosum and extends upward, attaching to the skull at the very top. It conducts impact energy from the skull deep into the brain, where it oscillates and induces strain in the corpus callosum.

Tire Cornering Simulation Using an Explicit Finite Element Analysis Code

1998 ◽  
Vol 26 (2) ◽  
pp. 109-119 ◽  
Author(s):  
M. Koishi ◽  
K. Kabe ◽  
M. Shiratori
Keyword(s):  
Finite Element Method ◽  
Finite Element Analysis ◽  
Finite Element ◽  
Test System ◽  
Experimental Results ◽  
The Finite Element Method ◽  
Element Analysis ◽  
Explicit Finite Element ◽  
Explicit Finite Element Analysis ◽  
Element Method

Abstract The finite element method has been used widely in tire engineering. Most tire simulations using the finite element method are static analyses, because tires are very complex nonlinear structures. Recently, transient phenomena have been studied with explicit finite element analysis codes. In this paper, the authors demonstrate the feasibility of tire cornering simulation using an explicit finite element code, PAM-SHOCK. First, we propose the cornering simulation using the explicit finite element analysis code. To demonstrate the efficiency of the proposed simulation, computed cornering forces for a 175SR14 tire are compared with experimental results from an MTS Flat-Trac Tire Test System. The computed cornering forces agree well with experimental results. After that, parametric studies are conducted by using the proposed simulation.

scholarly journals Potential and limitations of finite element modelling in assessing structural integrity of coralline algae under future global change

2015 ◽  
Vol 12 (19) ◽  
pp. 5871-5883 ◽  
Author(s):  
L. A. Melbourne ◽  
J. Griffin ◽  
D. N. Schmidt ◽  
E. J. Rayfield
Keyword(s):  
Climate Change ◽  
Finite Element ◽  
Structural Integrity ◽  
Geometric Model ◽  
Algal Growth ◽  
Coralline Algae ◽  
Rocky Shores ◽  
Element Analysis ◽  
Scan Data ◽  
The Impact

Abstract. Coralline algae are important habitat formers found on all rocky shores. While the impact of future ocean acidification on the physiological performance of the species has been well studied, little research has focused on potential changes in structural integrity in response to climate change. A previous study using 2-D Finite Element Analysis (FEA) suggested increased vulnerability to fracture (by wave action or boring) in algae grown under high CO2 conditions. To assess how realistically 2-D simplified models represent structural performance, a series of increasingly biologically accurate 3-D FE models that represent different aspects of coralline algal growth were developed. Simplified geometric 3-D models of the genus Lithothamnion were compared to models created from computed tomography (CT) scan data of the same genus. The biologically accurate model and the simplified geometric model representing individual cells had similar average stresses and stress distributions, emphasising the importance of the cell walls in dissipating the stress throughout the structure. In contrast models without the accurate representation of the cell geometry resulted in larger stress and strain results. Our more complex 3-D model reiterated the potential of climate change to diminish the structural integrity of the organism. This suggests that under future environmental conditions the weakening of the coralline algal skeleton along with increased external pressures (wave and bioerosion) may negatively influence the ability for coralline algae to maintain a habitat able to sustain high levels of biodiversity.

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