scholarly journals The Effects of Curtain Airbag on Occupant Kinematics and Injury Index in Rollover Crash

2018 ◽  
Vol 2018 ◽  
pp. 1-12
Author(s):  
Hongyun Li ◽  
Chengyue Jiang ◽  
Dong Cui ◽  
Shuang Lu
Keyword(s):  
Restraint System ◽  
Head Acceleration ◽  
Physical Test ◽  
Injury Index ◽  
Hybrid Iii ◽  
Protection Area ◽  
Occupant Injuries ◽  
Occupant Kinematics ◽  
Head And Neck Injury ◽  
Rollover Crash

Background. Occupant injuries in rollover crashes are associated with vehicle structural performance, as well as the restraint system design. For a better understanding of the occupant kinematics and injury index in certain rollover crash, it is essential to carry out dynamic vehicle rollover simulation with dummy included. Objective. This study focused on effects of curtain airbag (CAB) parameters on occupant kinematics and injury indexes in a rollover crash. Besides, optimized parameters of the CAB were proposed for the purpose of decreasing the occupant injuries in such rollover scenario. Method and Material. The vehicle motion from the physical test was introduced as the input for the numerical simulation, and the 50% Hybrid III dummy model from the MADYMO database was imported into a simulation model. The restraint system, including a validated CAB module, was introduced for occupant kinematics simulation and injury evaluation. TTF setting, maximum inflator pressure, and protection area of the CAB were analysed. Results. After introducing the curtain airbag, the maximum head acceleration was reduced from 91.60 g to 49.52 g, and the neck Mx and neck Fz were reduced significantly. Among these CAB parameters, the TTF setting had the largest effect on the head acceleration which could reduce 8.6 g furthermore after optimization. The neck Fz was decreased from 3766.48 N to 2571.77 N after optimization of CAB protection area. Conclusions. Avoiding hard contact is critical for the occupant protection in the rollover crashes. The simulation results indicated that occupant kinematics and certain injury indexes were improved with the help of CAB in such rollover scenario. Appropriate TTF setting and inflator selection could benefit occupant kinematics and injury indexes. Besides, it was advised to optimize the curtain airbag thickness around the head contact area to improve head and neck injury indexes.

Development of an Improved Dummy Head for Use in Helmet Certification Tests

2000 ◽  
Author(s):  
Eric H. L. A. van den Bosch ◽  
Martijn W. B. M. Leensen ◽  
Nancy H. M. Klomp ◽  
Fons A. A. H. J. Sauren ◽  
Jac S. H. M. Wismans
Keyword(s):  
Brain Structure ◽  
Evaluation Process ◽  
Drop Test ◽  
Head Acceleration ◽  
First Order ◽  
Certification Tests ◽  
Hybrid Iii

Abstract First order improvements to the rigid headform, used in current helmet certification tests, are made by introducing a skull and brain structure. In developing the new headform certain requirements were taken into consideration. The new headform appears to meet all requirements but one. The 200 mm drop test with Hybrid-III skin padding on the anvil resulted in too low resultant linear head accelerations. Using a stiffer, more realistic padding on the anvil resulted in a resultant linear head acceleration which satisfies the requirements (100 – 150 g). The padding plays an important role in the evaluation process. Because of the deformable skull, a fairly stiff padding has to be used in order to let the resultant linear head acceleration satisfy the requirements. In contrast to the 200 mm drop test experiments, the padding properties of the skin are of no importance when an EPS padding is placed between the skin and the anvil.

The Influence of Hard Hat Design Features on Head Acceleration Attenuation

2020 ◽  
pp. 1-7
Author(s):  
Arthur Alves Dos Santos ◽  
James Sorce ◽  
Alexandra Schonning ◽  
Grant Bevill
Keyword(s):  
Lead Shot ◽  
Construction Site ◽  
Head Acceleration ◽  
Protective Capacity ◽  
Design Features ◽  
Shell Design ◽  
Hybrid Iii ◽  
Hard Hat ◽  
Head Neck

This study evaluated the performance of 6 commercially available hard hat designs—differentiated by shell design, number of suspension points, and suspension tightening system—in regard to their ability to attenuate accelerations during vertical impacts to the head. Tests were conducted with impactor materials of steel, wood, and lead shot (resembling commonly seen materials in a construction site), weighing 1.8 and 3.6 kg and dropped from 1.83 m onto a Hybrid III head/neck assembly. All hard hats appreciably reduced head acceleration to the unprotected condition. However, neither the addition of extra suspension points nor variations in suspension tightening mechanism appreciably influenced performance. Therefore, these results indicate that additional features available in current hard hat designs do not improve protective capacity as related to head acceleration metrics.

Investigation of Heavy Truck Restraint System Effectiveness Through Finite Element Computer Simulations in Frontal Crashes

2016 ◽  
Author(s):  
Nathan Schulz ◽  
Chiara Silvestri Dobrovolny ◽  
Abhinav Mohanakrishnan
Keyword(s):  
Finite Element ◽  
Injury Severity ◽  
Seat Belt ◽  
Restraint System ◽  
Rigid Barrier ◽  
Heavy Trucks ◽  
Ring Location ◽  
Heavy Truck ◽  
Frontal Crashes ◽  
Occupant Kinematics

Computer finite element simulations play an important role in reducing the cost and time taken for prediction of a crash scenario. While interior crash protection has received adequate attention for automobiles, very little is known for commercial vehicle such as heavy trucks. The understanding of injury types for heavy trucks occupants in relation to different crash scenarios would help mitigation of the injury severity. Finite element computer models of the heavy truck cabin structure, interior cabin components, anthropomorphic test device (ATD) (also called dummy) and passive restraint systems were developed and assembled to simulate head-on crash of a heavy truck into a rigid barrier. The researchers developed a computer simulation parametric evaluation with respect to specific seat belt restraint system parameters for a speed impact of 56.3 km/h (35 mph). Restraint parameter variations within this research study are seat belt load limiting characteristics, inclusion of seat belt pretensioner, and variation of seat belt D-ring location. Additionally an airbag was included to investigate another restraint system. For each simulated impact characteristic and restraint system variation, the occupant kinematics were observed and occupant risks were assessed. Within the approximations and assumptions included in this study, the results presented in this paper should be considered as preliminary guidance on the effectiveness of the use of seat belt as occupant injury mitigation system.

Reducing Occupant Injury in Frontal Crashes for a Low-Floor City Bus

2005 ◽  
Author(s):  
Elham Sahraei Esfahani ◽  
Kurosh Darvish ◽  
Mohamad Parnianpour ◽  
Akbar Bateni
Keyword(s):  
Plastic Material ◽  
Material Model ◽  
Element Model ◽  
Driver Model ◽  
City Bus ◽  
Hybrid Iii ◽  
Occupant Injury ◽  
Occupant Injuries ◽  
Frontal Crashes ◽  
Elastic Plastic Material

In this research, the effect of beam buckling in a predefined direction is used to reduce occupant injuries in frontal crashes of an ultra-low-floor (ULF) city bus. In ULF buses, the floor structure consists of several longitudinal long beams, which in case of a frontal crash may buckle due to the axial impact. The direction of rotational acceleration of the driver seat due to buckling is highly affected by the position of the driver seat. A finite element model of an ULF bus was developed using LS-Dyna. The driver model, a Hybrid III 50th male dummy with deformable jacket and abdomen, was restrained to the seat with a 3-point belt. An Elastic-Plastic material model was used for the bus structure to investigate the buckling behavior of the beam elements. Using diagonal beams to guide the buckling in a desired direction, rewarding results were achieved in reducing the occupant injuries. For example, with an extra diagonal beam under the seat, the driver’s HIC15 was reduced from 739 to 415.7 and HIC36 from 791 to 700.6.

Validation of a Wireless Head Acceleration Measurement System for Use in Soccer Play

2010 ◽  
Vol 26 (4) ◽  
pp. 424-431 ◽  
Author(s):  
Erin Hanlon ◽  
Cynthia Bir
Keyword(s):  
Measurement System ◽  
Cross Correlation ◽  
Angular Acceleration ◽  
Strong Relationship ◽  
Head Acceleration ◽  
Acceleration Measurement ◽  
Hybrid Iii ◽  
Cross Correlations ◽  
Rms Error ◽  
Soccer Heading

Soccer heading has been studied previously with conflicting results. One major issue is the lack of knowledge regarding what actually occurs biomechanically during soccer heading impacts. The purpose of the current study is to validate a wireless head acceleration measurement system, head impact telemetry system (HITS) that can be used to collect head accelerations during soccer play. The HIT system was fitted to a Hybrid III (HIII) head form that was instrumented with a 3-2-2-2 accelerometer setup. Fifteen impact conditions were tested to simulate impacts commonly experienced during soccer play. Linear and angular acceleration were calculated for both systems and compared. Root mean square (RMS) error and cross correlations were also calculated and compared for both systems. Cross correlation values were very strong withr= .95 ± 0.02 for ball to head forehead impacts andr= .96 ± 0.02 for head to head forehead impacts. The systems showed a strong relationship when comparing RMS error, linear head acceleration, angular head acceleration, and the cross correlation values.

Design and Analysis of an Energy Absorbing Restraint System for Light Aircraft Crash-Impact

1974 ◽  
Vol 96 (2) ◽  
pp. 495-502 ◽  
Author(s):  
M. S. Hundal ◽  
R. W. McLay ◽  
L. Folsom
Keyword(s):  
Mathematical Model ◽  
Steel Wire ◽  
Plane Motion ◽  
General Aviation ◽  
Restraint System ◽  
Occupant Restraint System ◽  
Crash Protection ◽  
Occupant Injuries ◽  
Energy Absorbing ◽  
Aircraft Crash

The application of a miniaturized energy absorbing mechanism to a light airplane occupant restraint system is presented. The mechanism absorbs energy through the continuous plastic deformation of a steel wire, closely approximating a constant force energy absorber. The design philosophy and the installation details for the aircraft are presented. A mathematical model is used for determining the occupant response during aircraft crash. The model considers plane motion of the aircraft and the human body, the latter being approximated by five rigid body segments. Occupant displacements and curves for accelerations and restraint forces are presented for a typical survivable light aircraft crash. The experimental results and the mathematical model response suggest that incorporation of the energy absorbing mechanism would produce a significant decrease in occupant injuries and fatalities. A parametric study of the occupant/restraint system is presented. Recommendations are made on steps towards improved crash protection and survival in general aviation.

scholarly journals New test method with a Hybrid III Anthropomorphic Dummy for Textile Safety Harnesses

2020 ◽  
Vol 28 (1(139)) ◽  
pp. 81-86
Author(s):  
Krzysztof Baszczyński
Keyword(s):  
Test Method ◽  
Strength Testing ◽  
Head Acceleration ◽  
Testing Methods ◽  
Testing Method ◽  
Experimental Stand ◽  
Hybrid Iii ◽  
Mechanical Factors ◽  
Fall Arrest ◽  
Full Body

A full body harness is a basic component of personal fall arrest equipment. It is made from webbing connected by seams and metal fittings to firmly hold and support the user’s body. The paper proposes a new method for full body harness testing using a Hybrid III anthropomorphic dummy; also the design of the experimental stand and software used are described. The method analyses the behaviour of a dummy during a fall arrest under well-defined conditions. The critical mechanical factors measured during the study presented were: the head acceleration, forces acting on the spine, the position of the dummy, the impacts of harness elements to the head, etc. The tests identified some potentially dangerous phenomena associated with falls from a height. The harness testing method developed turned out to be a valuable tool that should be applied in conjunction with existing strength testing methods.

An Improved Dummy Neck Assembly for Dynamic Rollover Testing

2010 ◽  
Author(s):  
Jacqueline G. Paver ◽  
Justin Caplinger ◽  
Garrett Mattos ◽  
Donald Friedman
Keyword(s):  
Real World ◽  
Muscle Tension ◽  
Human Head ◽  
Matched Pair ◽  
Neck Injuries ◽  
Stiff Neck ◽  
Ongoing Research ◽  
Compliance Testing ◽  
Hybrid Iii ◽  
Rollover Crash

In the U.S., more than 27,000 catastrophic and fatal injuries occur annually in rollover crashes. Due to the incidence and severity of injuries in rollover crashes, a strategy for injury mitigation is dynamic compliance testing with dummy-occupied vehicles and occupant protection requirements, similar to that required for frontal and side impacts. Presently, there are dynamic vehicle rollover test devices like the Controlled Rollover Impact System and the Jordan Rollover System that realistically recreate real-world rollover crash scenarios. However, the Hybrid III dummy, which is considered to be the best available human surrogate for dynamic rollover tests, has a very stiff neck with limited biofidelity in rollover crashes; the Hybrid III neck is much stiffer than the human neck. Catastrophic human head or neck injuries resulting from roof interaction and partial ejection in real-world rollover crashes are poorly replicated by dynamic rollover tests with the non-biofidelic Hybrid III dummy neck. Only with a more biofidelic dummy can effective testing result in injury mitigation in rollover crashes. This study is part of an ongoing research project aimed at mitigating catastrophic human neck injuries in real-world rollover crashes. The goal was to develop a biofidelic neck assembly for the Hybrid III dummy in rollover crash environments. The design goals of this prototype neck included decreased stiffness and a mechanism that represents the unknowable human muscle tension in rollover crash environments. This paper and its companion paper in this conference introduce the new neck design, present results of matched-pair tests that compare the responses of the new neck with the production Hybrid III neck, and propose preliminary rollover injury criteria for this neck. The neck demonstrates repeatability, improved biofidelity, which results in more realistic occupant kinematics, dynamics, injury prediction, and evaluation of various countermeasures.

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