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Seventeen concussive helmet-to-helmet impacts occurring in National Football League (NFL) games were analyzed using video footage and reconstructed by launching helmeted crash test dummies into each other in a laboratory. Helmet motion on-field and in the laboratory was tracked in 3D before, during, and after impact in multiple high frame rate video views. Multiple (3–10) tests were conducted for each of the 17 concussive cases (100 tests total) with slight variations in input conditions. Repeatability was assessed by duplicating one or two tests per case. The accuracy of the input conditions in each reconstruction was assessed based on how well the closing velocity, impact locations, and the path eccentricity of the dummy heads matched the video analysis. The accuracy of the reconstruction output was assessed based on how well the changes in helmet velocity (translational and rotational) from the impact matched the video analysis. The average absolute error in helmet velocity changes was 24% in the first test, 20% in the tests with the most accurate input configuration, and 14% in the tests with minimal error. Coefficients of variation in 22 repeated test conditions (1–2 per case) averaged 3% for closing velocity, 7% for helmet velocity changes, and 8% for peak head accelerations. Iterative testing was helpful in reducing error. A combination of sophisticated video analysis, articulated physical surrogates, and iterative testing was required to reduce the error to within half of the effect size of concussion.

Physical reconstructions are a valuable methodology for quantifying head kinematics in sports impacts. By recreating the motion of human heads observed in video using instrumented test dummies in a laboratory, physical reconstructions allow for in-depth study of real-world head impacts using well-established surrogates such as the Hybrid III crash test dummy. The purpose of this paper is to review all aspects of the physical reconstruction methodology and discuss the advantages and limitations associated with different choices in case selection, study design, test surrogate, test apparatus, text matrix, instrumentation, and data processing. Physical reconstructions require significant resources to perform and are therefore typically limited to small sample sizes and a case series or case–control study design. Their accuracy may also be limited by a lack of dummy biofidelity. The accuracy, repeatability, and sensitivity of the reconstruction process can be characterized and improved by good laboratory practices and iterative testing. Because wearable sensors have their own limitations and are not available or practical for many sports, physical reconstructions will continue to provide a useful and complementary approach to measuring head acceleration in sport for the foreseeable future.

The effects of a road accident where one vehicle hits its front on the side of another one are explored. In such cases, the impacted vehicle’s side is usually significantly deformed, which causes a risk of serious injury to vehicle occupants. An analysis of the front-to-side collision covers many nonlinear and highly complex processes, especially when it is based on the collision energy balance. For the analysis, a model of a front-to-side motorcar collision and a dummy representing the impacted vehicle’s driver was prepared. The model simulations carried out were supplemented with important experimental test results. The model validation and the drawing of conclusions from research results were based on crash test results. The shares of major components in the front-to-side collision energy balance were determined. The impact energy has been proposed as an alternative predicate of the road accident effects; as a measure of the effects, the risk of injury to vehicle occupant’s head and torso is considered. The model simulations were found to be in good conformity with experimental test results. The research results enabled determining the relation between the side impact energy and the risk of dummy’s head and torso injuries according to the Abbreviated Injury Scale. The relation obtained was approximated using the logit model. This relation helps to reconstruct road accidents and to improve the car side’s passive safety systems. A discussion of the results obtained has shown good consistence between the results of this work and other comparable research results.

Within the continuous development of automotive safety and increasingly stringent crash regulations under the Vision Zero initiative, physical crash testing remains essential for assessing occupant injury risk. This study focuses on the evaluation of occupant dynamics in full-overlap frontal collisions, based on real crash tests. Key parameters influencing injury severity, including impact speed, seat belt usages, and occupant anthropometry, were analyzed to identify worst-case scenarios. Frontal crash test protocols from regulatory and consumer programs were included in the analysis. Physical tests were conducted according to FMVSS 208 using Hybrid III 50th percentile male and 5th percentile female dummies. Both belt-restrained and unrestrained (unbelted) conditions were considered. Numerical simulations using LS-DYNA are used as a complementary tool to support and extend the interpretation of the experimental findings, particularly in assessing the influence of impact speed, seat belt usage, and occupant anthropometry on injury metrics. The results evaluate the factors with the greatest impact on injury risk and demonstrate the importance of physical frontal crash tests in the evaluation of the occupant protection. All experimental tests were carried out at IAV Vehicle Safety.

There is limited data on transporting small children in hip spica casts used to treat pediatric femur fractures. Specific challenges include the fixed position of the body in the casted position and the increased size of the child due to cast thickness. Additionally, children less than 2 years old are recommended to be rear facing during transportation. This traveling position requires seats that are specifically designed to accommodate the small size of the child as well as accommodate the rear facing position. While seats able to accommodate casted children are available, it is unclear if they provide adequate protection in side impact collisions for rear facing spica casted infants. Therefore, the aim of this study was to evaluate traumatic injury metrics in a side impact collision model where a spica casted infant crash dummy was restrained in currently available car seats. Two seats designed for spica casted children (R82 Quokka, Merritt Wallenberg) and two traditional car seats (Britax Emblem, Graco Sequel) able to accommodate a casted one-year-old crash test dummy were identified. Side impact collision testing was performed with the dummy positioned in the rear facing position and injury metrics recorded. Testing identified contact between the dummy's head and the door panel for a specialty spica car seat without protective side-wings for the head. All other seats contained side wings and prevented door-head contact. Casted children should be transported in a seat able to accommodate the cast and safely restrain them. Our results demonstrate the importance of side wing protection in any seat used to transport these children as side bolsters may help decrease the potential for head contact with the door and lower the risk of severe head injury. •Safe transport of spica casted infants remains challenging•Car seats often do not fit and have not been evaluated in side impact crashes•Seats with side wings reduce the risk for traumatic injury

Accurately estimating injury severity in crashes relies on understanding vehicle occupant movements. This is simulated using crash test dummies in controlled test cases. Currently, stationary high-speed cameras positioned outside the vehicle track the kinematics of the different dummy parts by following optical markers placed on these dummies. However, onboard high-speed cameras are primarily used for documentation and are not suitable for determining 3d object kinematics with the required accuracy. Furthermore, with the increasing sophistication of modern airbag systems, points inside the vehicle that need to be visible for the stationary cameras may be obscured by the deployment of airbags. To address this limitations, we propose relocating onboard high-speed cameras inside the vehicle and investigating the resulting uncertainties. The dynamic nature of crash events presents challenges for these onboard cameras to accurately self-localize, given the rapid changes occurring within the vehicle. To overcome this challenge, we introduce a novel method for determining the position and orientation of the onboard stereo camera pair at each time point, followed by an analysis of the uncertainties involved. We use Monte Carlo simulations and bootstrapping techniques to estimate the uncertainties associated with point measurements in crash test scenarios. And therefore we can determine the object kinematics and their related uncertainties inside the vehicle using the onboard high-speed cameras instead of the stationary high-speed cameras.

The article presents the displacement of individual body parts of volunteers during a controlled crash test at low speed. The crash test stand used is equipped with a vehicle seat with standard seat belts, which moves along the ramp rails. The stand enables both front, side and rear crash tests. The stand enables crash tests from 5 km/h to 20 km/h. The aim of the research is to compare the displacements of individual parts of the volunteers’ body, taking into account the division into sex. A study carried out on 130 volunteers (80 men and 50 women), at a collision speed of 15 km/h, showed slight differences in the trajectory of the volunteers’ head movement. Before the study, the volunteers were measured and weighed, and then assigned to the appropriate population percentile. Volunteers were classified into a given percentile group on the basis of the mean of 15 anthropometric dimensions of individual body parts. The obtained results are the basis for building a physical model of a dummy.

This paper presents an optimized method for evaluating and enhancing the crashworthiness of an electric vehicle (EV) battery frame, leveraging finite element model (FEM) simulations with minimal computational effort. The study begins by utilizing a publicly available LS-DYNA model of a conventional Toyota Camry, simplifying it to include only the structures relevant to a side pole crash scenario. The crash simulations adhere to FMVSS214 and UNR135 standards, while also extending to higher speeds of 45 km/h to evaluate performance under more severe conditions. A dummy frame with virtual mass is integrated into the model to approximate the realistic center of gravity (COG) of an EV and to facilitate visualization. Based on the side pole crash results, critical parameters are extracted to inform the development of load cases for the EV battery. The proposed battery frame, constructed from aluminum, houses a representative volume of battery cells. These cells are defined through a homogenization process derived from individual and pack of cell crash tests. The crashworthiness of the battery frame is assessed by measuring the overall intrusion along the Y-axis and the specific intrusion into the representative volume. This method not only highlights the challenges of adapting conventional vehicle platforms for EVs or for dual compatibility with both conventional and electric powertrains but also provides a framework for developing and testing battery frames independently. By creating relevant load cases derived from full vehicle crash data, this approach enables battery frames to be optimized and evaluated as standalone components, offering a method for efficient and adaptable battery frame development. This approach provides a streamlined yet effective process for optimizing the crash performance of EV battery systems within existing vehicle platforms.

Presently, most passive safety tests are performed with a precisely specified seat position and carefully seated ATD (anthropomorphic test device) dummies. Facing the development of autonomous vehicles, as well as the need for safety verification during crashes with various seat positions such research is even more urgently needed. Apart from the numerical environment, the existing testing equipment is not validated to perform such an investigation. For example, ATDs are not validated for nonstandard seatback positions, and the most accurate method of such research is volunteer tests. The study presented here was performed on a sled test rig utilizing a 50cc Hybrid III dummy according to a full factorial experiment. In addition, input factors were selected in order to verify a safe test condition for surrogate testing. The measured value was head acceleration, which was used for calculation of a head injury criterion. What was found was an optimal seat angle −117°—at which the head injury criteria had the lowest represented value. Moreover, preliminary body dynamics showed a danger of whiplash occurrence for occupants in a fully-reclined seat.