Investigation of occupant kinematics and injury risk in a reclined and rearward-facing seat under various frontal crash velocities

Author(s):  
Ngo Anh Vu ◽  
Julian Becker ◽  
Dinesh Thirunavukkarasu ◽  
Peter Urban ◽  
Saiprasit Koetniyom ◽  
...  
Author(s):  
MohammadReza Seyedi ◽  
Sungmoon Jung

Rollover crashes of buses are usually associated with multiple impacts that can result in complex interactions between passengers and a bus superstructure. Although there have been a few field data studies that provide some insights into occupant injuries (e.g. severity and distribution of injuries) during the real-world bus rollover crash, because they had used post-crash data, the occupant kinematics and injury mechanisms were not completely detailed in their results. Based on a literature review, available numerical and experimental studies on a bus rollover safety have mainly focused on structural integrity rather than considering occupant responses in their assessment. In addition, their results about occupant responses in bus rollover crashes show some discrepancies in terms of the estimated injury distribution, severity, and causes. Therefore, the main objective of this study was to provide a more detailed understanding of the occupant kinematics and associated injury risk during the ECE R66 tilt table bus rollover test using validated finite element (FE) models. The ECE R66 tilt table rollover was simulated using a full finite element model of the bus. A 50th percentile male Hybrid III Anthropomorphic test device (ATD) and EuroSID-2re FE models were selected to simulate the occupant’s motion. Each ATD was seated adjacent to the impacted side wall and restrained with a 2-point seatbelt. Simulation parameters included two impact surface friction values and different side window conditions. The results indicated that both ATD estimated the highest injury risk when the partial ejection occurred. They predicted a similar injury risk for the head and thorax. The ES-2re estimated a very low risk of neck injury in all simulations, whereas the Hybrid III estimated the high risk of a neck injury. Finally, recommendations to potentially reduce the injuries were provided and possible future works were suggested.


Author(s):  
Randa Radwan Samaha ◽  
Priyaranjan Prasad ◽  
Sarath Kamalakkannan ◽  
Vamsi Kommineni ◽  
Lilly Nix ◽  
...  

Occupant model environments (MADYMO) are developed for four surrogate vehicles for injury risk computation in frontal crash fleet simulations: a small passenger car, a midsize passenger car, a midsize sport utility vehicle and a full size pickup truck. This research supports the initial implementation of a novel methodology for Evaluating Fleet, i.e., self and partner, Protection (EFP) of new vehicle designs through a systems modeling approach driven by structural and occupant modeling and real world crash and full scale test data. A two part general framework for development of occupant models for fleet vehicles is established: model development (Part I) and model verification and robustness evaluation (Part II). In Part I, current generic occupant models with seat belt and airbag restraints are obtained from restraint manufacturers and then modified to reflect the interior geometry and clearances of the desired vehicle. Data from finite element structural simulations, including the occupant compartment geometry, crash pulse, and toe pan intrusions, are utilized to drive the MADYMO models. Restraint system and dummy seating changes are incorporated to achieve a realistic match for both midsize male and small female driver dummy responses from available frontal crash tests. Part II involves comparing occupant responses from simulation and test data, and assessing trends in occupant responses in selected crash configurations for application in frontal crash fleet simulations.


PLoS ONE ◽  
2021 ◽  
Vol 16 (9) ◽  
pp. e0257292
Author(s):  
Cyrille Grébonval ◽  
Xavier Trosseille ◽  
Philippe Petit ◽  
Xuguang Wang ◽  
Philippe Beillas

Current highly automated vehicle concepts include reclined seat layouts that could allow occupants to relax during the drive. The main objective of this study was to investigate the effects of seat pan and pelvis angles on the kinematics and injury risk of a reclined occupant by numerical simulation of a frontal sled test. The occupant, represented by a detailed 50th percentile male human body model, was positioned on a semi-rigid seat. Three seat pan angles (5, 15, and 25 degrees from the horizontal) were used, all with a seatback angle of 40 degrees from the vertical. Three pelvis angles (60, 70, and 80 degrees from the vertical), representing a nominal and two relaxed sitting positions, were used for each seat pan angle. The model was restrained using a pre-inflated airbag and a three-point seatbelt equipped with a pretensioner and a load limiter before being subjected to two frontal crash pulses. Both model kinematic response and predicted injury risk were affected by the seat pan and the pelvis angles in a reclined seatback position. Submarining occurrence and injury risk increased with lower seat pan angle, higher pelvis angle, and acceleration pulse severity. In some cases (in particular for a 15 degrees seat pan), a small variation in seat pan or pelvis angle resulted in large differences in terms of kinematics and predicted injury. This study highlights the potential effects of the seat pan and pelvis angles for reclined occupant protection. These parameters should be assessed experimentally with volunteers to determine which combinations are most likely to be adopted for comfort and with post mortem human surrogates to confirm their significance during impact and to provide data for model validation. The sled and restraint models used in this study are provided under an open-source license to facilitate further comparisons.


1999 ◽  
Vol 4 (5) ◽  
pp. 4-7 ◽  
Author(s):  
Laura Welch

Abstract Functional capacity evaluations (FCEs) have become an important component of disability evaluation during the past 10 years to assess an individual's ability to perform the essential or specific functions of a job, both preplacement and during rehabilitation. Evaluating both job performance and physical ability is a complex assessment, and some practitioners are not yet certain that an FCE can achieve these goals. An FCE is useful only if it predicts job performance, and factors that should be assessed include overall performance; consistency of performance across similar areas of the FCE; consistency between observed behaviors during the FCE and limitations or abilities reported by the worker; objective changes (eg, blood pressure and pulse) that are appropriate relative to performance; external factors (illness, lack of sleep, or medication); and a coefficient of variation that can be measured and assessed. FCEs can identify specific movement patterns or weaknesses; measure improvement during rehabilitation; identify a specific limitation that is amenable to accommodation; and identify a worker who appears to be providing a submaximal effort. FCEs are less reliable at predicting injury risk; they cannot tell us much about endurance over a time period longer than the time required for the FCE; and the FCE may measure simple muscular functions when the job requires more complex ones.


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