Pediatric Wheelchair Transportation Safety: Transit Manual Wheelchair Design Guidelines and Injury Risk of 6-year-old Children in a Frontal Motor Vehicle Impact

Children with disabilities often cannot be seated in standard child seats or automobile seats because of physical deformities or poor trunk and head control. Therefore, when children with disabilities are transported to schools and developmental facilities, they often remain seated in their wheelchairs in vehicles such as school buses and family vans. Children who must travel seated in their wheelchairs are excluded from the protections dictated by the federal and state laws related to child protection in motor vehicle crashes. This dissertation investigated the safety of children in wheelchairs in transit, mainly using computer simulation software. Three pediatric manual wheelchairs were tested with a Hybrid III 6-year-old ATD in accordance with the ANSI/RESNA WC-19 standard. Using sled test data, a computer model representing a Zippie wheelchair seated with a Hybrid III 6-year-old ATD subjected to a 20g/48kph frontal crash was developed and validated in MADYMO. The injury risks of 6-year-old wheelchair occupants in a frontal impact motor vehicle crash was investigated by analyzing sled test data and by using the pediatric wheelchair computer model. The loads imposed on the wheelchair and occupant restraint system under 20g/48kph frontal impact conditions with varying wheelchair setup conditions was also investigated using the computer model. The study results showed that a 6-year-old wheelchair seated occupant may be subjected to a risk of neck and chest injuries in a frontal impact motor vehicle crash. Results also showed that altering wheelchair settings does have impact on kinematics and injury risk of a 6-year-old wheelchair occupant in a frontal motor vehicle crash. Changing wheelchair settings also had impact on wheelchair kinematics and loads imposed on the wheelchair and occupant restraint system. The study results presented in this dissertation will provide guidelines for manufacturers designing pediatric transit wheelchairs, seating, and occupant restraint system. The pediatric wheelchair model developed in this study will provide a foundation for studying the response of a manual pediatric wheelchair and a child occupant in crashes. Moreover, the model will promote the study of associated injury risks for pediatric wheelchair users in motor vehicle crashes

Post mortem human subject and dummy response in frontal deceleration

28ème congrès de la société de biomécanique, POITIERS, FRANCE, 11-/09/2003 - 12/09/2003In the European Union, the assessment of die protection offered by a vehicle to a restrained occupant in case of frontal collision, is based on biomechanical data measured on the Hybrid III crash test dummy as described by the European Frontal Directive (Directive 96/79/EC). Ibis dummy was developed in the 70's and is based on biomechanical knowledge from that time. The Thor dummy (Test device for Human Occupant Restraint) developed by NHTSA (USA Administration) is based on more recent biomechanical knowledge. Many parts of the dummy have been designed and modified to produce a more humanlike response to frontal impact loading. The general objective of the FID European research program (improved Frontal Impact protection through a world frontal impact Dummy) is a European contribution to the evaluation of a worldwide dummy in the frontal impact. The paper presents new biomechanical data, based PMHS (Post Mortem Human Subject) tests, under different frontal impact conditions. The same tests with exactly the same instrumentation mounted at the same location were performed with Hybrid III and with the Thor-alpha to assess die biofidelity of these dummies with respect to these biomechanical data

FIMCAR XI: FIMCAR Final Assessment Approach

The objectives of the FIMCAR (Frontal Impact and Compatibility Assessment Research) project are to answer the remaining open questions identified in earlier projects (such as understanding of the advantages and disadvantages of force based metrics and barrier deformation based metrics, confirmation of specific compatibility issues such as structural interaction, investigation of force matching) and to finalise the frontal impact test procedures required to assess compatibility. Research strategies and priorities were based on earlier research programs and the FIMCAR accident data analysis. The identified real world safety issues were used to develop a list of compatibility characteristics which were then prioritised within the consortium. This list was the basis for evaluating the different test candidates. This analysis resulted in the combination of the Full Width Deformable Barrier test (FWDB) with compatibility metrics and the existing Offset Deformable Barrier (ODB) as described in UN-ECE Regulation 94 with additional cabin integrity requirement as being proposed as the FIMCAR assessment approach. The proposed frontal impact assessment approach addresses many of the issues identified by the FIMCAR consortium but not all frontal impact and compatibility issues could be addressed

CORRELATION ANALYSIS OF VEHICLE FRONTAL IMPACT PARAMETERS

The article considers a possible improvement of road vehicle safety by using eCall – a system which initiates an emergency call in case of traffic accident. A possible way of better description of a frontal impact accident of a vehicle is examined and enriched by the information from the onboard e-call unit. In this article, we analyze results of frontal crash tests with different types of barriers and overlapping area and look for the correlation between the individual vehicle and collision parameters in order to provide a better description of the severity of the accident by the eCall system. The relation among the selected parameters is described using the correlation analysis

The biomechanics of lower limb injuries in frontal-impact road traffic collisions

Aim: We aimed to review the biomechanics of lower limb injuries caused by frontal-impact road traffic collisions.Methods: In this narrative review, we identified articles through pubmed, Scopus and Science Direct search engines for the period of 1990-2014. Search terms included: “biomechanics”, “lower limb injury”, “hip injury”, “knee injury”, “foot and ankle injury” and “frontal impact collision”. We studied factors affecting the anatomical site, frequency and severity of the injuries.Results: The most common reported mechanisms of injury were: the impaction of the knee with the dashboard resulting in acetabular fracture or posterior hip dislocation; and toepan intrusion in combination with forceful application of the brake resulting in foot and ankle fractures. The probability of an occupant sustaining significant injury to the hip is increased in taller males, and being out of position during the collision. The probability of an occupant sustaining a fracture to the foot and ankle is increased in shorter female occupants with a large overlap impact or a near oblique collision.Conclusion: Understanding the biomechanics of frontal-impact road traffic collisions is useful in alerting clinicians to the potential lower limb injuries sustained in these collisions.Keywords: Biomechanics, frontal-impact collisions, lower limb injury, knee, thigh and hip injury, lower leg, foot and ankle injury

Energy absorption of car chassis rails under impact conditions

Although the levels of safety offered to the occupants of cars has improved considerably in the recent past, car users still comprise more than 50% of all European road user fatalities. The predominant accident type experienced is a frontal impact with another car. at speeds below 64 kmh (40 mph). This type of accident is reproduced by the new European offset deformable barrier frontal impact test requirement which supplements the fully distributed. rigid barrier impact test that is still required in many countries around the world

Crash Analysis and Energy Absorption Characteristics of S-shaped Longitudinal Members

This paper presents finite element simulations of the crash behavior and the energy absorption characteristics of thin S-shaped longitudinal members with variable cross-sections made of different materials to investigate the design of optimized energy-absorbing members. Numerical studies are carried out by simulation via the explicit finite element code LS-DYNA [1] to determine the desired variables for the design of energy-absorbing members. The specific energy absorption (SEA), the weight of the members and the peak force responses during the frontal impact are the main measurements of the S-shaped members' performance. Several types of inner stiffening members are also investigated to determine the influence of the additional stiffness on the crash behavior

Computational simulation of frontal impact of motorcycle telescopic fork

This paper presents modelling aspects of a high fidelity finite element model of a motorcycle telescopic fork. For validation purpose, a series of impact tests of which a frontal impact load imposed on the individual fork by a rigid striker was conducted using factorial experiment approach. The model was then used to simulate all the impacts accordingly. The outcomes were evaluated in terms of permanent deformations of the fork, energy dissipated in the impact, and the velocity and displacement time histories of the striker. The overall performance and sensitivity of the model was also assessed using the factorial analysis. The deviations of time histories data were quantified by mean error, mean absolute error and root mean square error. The key responses of the fork were found to be successfully simulated and compared well to the test results. The computed largest value among the respective metrics over the total errors was 6.2% of which corresponding to the root mean square error of the displacement time histories data, whereas others were less than 3%. It is thus concluded that the fork model has been successfully validated and the modelling methods has been established. Recommendations for improvements were also given in the paper