The Experts below are selected from a list of 97863 Experts worldwide ranked by ideXlab platform
Philippe Beillas - One of the best experts on this subject based on the ideXlab platform.
-
Effect of anthropometry scaling on the response of the piper child scalable Human Body Model subject to pelvic impact
Journal of Biomechanics, 2020Co-Authors: Marie-christine Chevalier, Philippe BeillasAbstract:The Open Source PIPER child scalable Human Body Model was publicly released in April 2017 (www.piper-project.org) along with frontal and side impact validation conditions. The objective of this paper is to investigate the effect of anthropometry scaling on the response of the Model in side pelvic impact. Three setups from two published studies were used: (1) a lateral drop test (2) a greater trochanter impact with a rigid pendulum (3) a pelvis side impact with a flat surface. The first study used scaling assumption developed for crash test dummy design (setups 1 and 2) and the second performed tests on post mortem Human surrogates. The baseline 6 years old child Model was scaled using a Model morphing methodology to match the stature and weight of the surrogates used in the two published studies. Overall, the main trends observed in the three setups can be approached using the baseline Model. Although the Model morphing did not account for specific skeletal dimensions, it reduced some of the discrepancies between Model response and reference for the drop test and flat plate impact. However, it had little effect on the pendulum test. In that case, the Model response was in the corridor at low speed but above at higher speeds. Possible reasons for this difference should be further investigated.
-
Transformation Smoothing to use after Positioning of Finite Element Human Body Models
2018Co-Authors: Tomas Janak, Yoann Lafon, Philippe Petit, Philippe BeillasAbstract:While positioning Finite Element Human Body Models is required for many applications, positioning techniques often degrade the mesh quality or result in soft tis sues artefacts. This study presents a method to smooth the transformation between two states of the same Human Body Model in an attempt to maintain the initial element quality, conserve gaps between disconnected components and keep bones as rigid. Illustrative workflows are provided for three positioning test cases using either the PIPER positioning tool or a finite element simulation, and either the PIPER Child or the GHBMC M50?O detailed Human Body Model. The workflows describe how to correct surface artefacts such as unrealistic folds or how to remove elements with negative volumes resulting from the PIPER positioning tool, by using a combination of surface smoothing and transformation smoothing. Parameters and performance are discussed to help future applications. The approach requires limited user interaction and produces a smoothed Model within a few minutes, in most cases. The transformation smoothing is independent of the positioning approach and the topology of the Human Body Model, making it potentially applicable to multiple scenarios. The method is implemented within the PIPER open source framework.
-
Side impact applications of the PIPER scalable child Human Body Model
2017Co-Authors: Philippe Beillas, Anicet Le Ruyet, Marie-christine ChevalierAbstract:The PIPER scalable child Human Body Model was recently released. It is scalable as a function of stature/age within the PIPER software. While several applications have been performed in frontal impact as new versions of the Model were developed, no side impact applications have been reported up to now. The objectives of the current study were to investigate the usability of the PIPER child Model and software for side impact through two applications related to the effect of anthropometric variations. In the first application, the pelvic region validation setup from Ouyang et al. (2003) was investigated using five subject specific Models. The anthropometric variations were found to partially explain the experimental variability. In the second application, the extreme anthropometric range possibly represented by the Q3 dummy in the regulation R129 was studied. A large effect was also observed on the response in simplified side impact simulations. The results should be considered as preliminary considering some of the statistical and setup assumptions made to build the extreme Models. However, the methodology that was developed could be used with different assumptions to refine the extreme Models, and these could be use in the future to check the CRS dynamic behaviour not only for dummy dimensions but for the complete range of anthropometry a dummy is covering.
-
An investigation of Human Body Model morphing for the assessment of abdomen responses to impact against a population of test subjects
Traffic Injury Prevention, 2017Co-Authors: Philippe Beillas, Fabien BerthetAbstract:Objective: Human Body Models have the potential to better describe the Human anatomy and variability than dummies. However, data sets available to verify the Human response to impact are typically limited in numbers, and they are not size or gender specific. The objective of this study was to investigate the use of Model morphing methodologies within that context. Methods: In this study, a simple Human Model scaling methodology was developed to morph two detailed Human Models (Global Human Body Model Consortium Models 50th male, M50, and 5th female, F05) to the dimensions of post mortem Human surrogates (PMHS) used in published literature. The methodology was then successfully applied to 52 PMHS tested in 14 impact conditions loading the abdomen. The corresponding 104 simulations were compared to the responses of the PMHS and to the responses of the baseline Models without scaling (28 simulations). The responses were analysed using the CORA method and peak values. Results: The results suggest that Model scaling leads to an improvement of the predicted force and deflection but has more marginal effects on the predicted abdominal compressions. M50 and F05 Models scaled to the same PMHS were also found to have similar external responses, but large differences were found between the two sets of Models for the strain energy densities in the liver and the spleen for mid-abdomen impact simulations. These differences, which were attributed to the anatomical differences in the abdomen of the baseline Models, highlight the importance of the selection of the impact condition for simulation studies, especially if the organ location is not known in the test. Conclusions: While the methodology could be further improved, it shows the feasibility of using Model scaling methodologies to compare Human Models of different sizes and to evaluate scaling approaches within the context of Human Model validation.
-
Effect of Abdominal Loading Location on Liver Motion: Experimental Assessment using Ultrafast Ultrasound Imaging and Simulation with a Human Body Model
Stapp Car Crash Journal, 2016Co-Authors: Anicet Le Ruyet, Fabien Berthet, Frédéric Rongieras, Philippe BeillasAbstract:A protocol based on ultrafast ultrasound imaging was applied to study the in situ motion of the liver while the abdomen was subjected to compressive loading at 3 m/s by a hemispherical impactor or a seatbelt. The loading was applied to various locations between the lower abdomen and the mid thorax while feature points inside the liver were followed on the ultrasound movie (2000 frames per second). Based on tests performed on five post mortem Human surrogates (including four tested in the current study), trends were found between the loading location and feature point trajectory parameters such as the initial angle of motion or the peak displacement in the direction of impact. The impactor tests were then simulated using the GHBMC M50 Human Body Model that was globally scaled to the dimensions of each surrogate. Some of the experimental trends observed could be reproduced in the simulations (e.g. initial angle) while others differed more widely (e.g. final caudal motion). The causes for the discrepancies need to be further investigated. The liver strain energy density predicted by the Model was also widely affected by the impact location. Experimental and simulation results both highlight the importance of the liver position with respect to the impactor when studying its response in situ.
Joel D. Stitzel - One of the best experts on this subject based on the ideXlab platform.
-
Modeling Human Volunteers in Multidirectional, Uni-axial Sled Tests Using a Finite Element Human Body Model
Annals of Biomedical Engineering, 2019Co-Authors: James P. Gaewsky, Derek A. Jones, Bharath Koya, F. Scott Gayzik, Xin Ye, Kyle P. Mcnamara, Ashley A. Weaver, Jacob B. Putnam, Jeffrey T. Somers, Joel D. StitzelAbstract:A goal of the Human Research Program at National Aeronautics and Space Administration (NASA) is to analyze and mitigate the risk of occupant injury due to dynamic loads. Experimental tests of Human subjects and biofidelic anthropomorphic test devices provide valuable kinematic and kinetic data related to injury risk exposure. However, these experiments are expensive and time consuming compared to computational simulations of similar impact events. This study aimed to simulate Human volunteer biodynamic response to unidirectional accelerative loading. Data from seven experimental studies involving 212 volunteer tests performed at the Air Force Research Laboratory were used to reconstruct 13 unique loading conditions across four different loading directions using finite element Human Body Model (HBM) simulations. Acceleration pulses and boundary conditions from the experimental tests were applied to the Global Human Body Models Consortium (GHBMC) simplified 50th percentile male occupant (M50-OS) using the LS-Dyna finite element solver. Head acceleration, chest acceleration, and seat belt force traces were compared between the experimental and matched simulation signals using correlation and analysis (CORA) software and averaged into a comprehensive response score ranging from 0 to 1 with 1 representing a perfect match. The mean comprehensive response scores were 0.689 ± 0.018 (mean ± 1 standard deviation) in two frontal simulations, 0.683 ± 0.060 in four rear simulations, 0.676 ± 0.043 in five lateral simulations, and 0.774 ± 0.013 in two vertical simulations. The CORA scores for head and chest accelerations in these simulations exceeded mean scores reported in the original development and validation of the GHBMC M50-OS Model. Collectively, the CORA scores indicated that the HBM in these boundary conditions closely replicated the kinematics of the Human volunteers across all loading directions.
-
Robust Human Body Model injury prediction in simulated side impact crashes.
Computer methods in biomechanics and biomedical engineering, 2015Co-Authors: Adam J. Golman, Kerry A. Danelson, Joel D. StitzelAbstract:This study developed a parametric methodology to robustly predict occupant injuries sustained in real-world crashes using a finite element (FE) Human Body Model (HBM). One hundred and twenty near-side impact motor vehicle crashes were simulated over a range of parameters using a Toyota RAV4 (bullet vehicle), Ford Taurus (struck vehicle) FE Models and a validated Human Body Model (HBM) Total Human Model for Safety (THUMS). Three bullet vehicle crash parameters (speed, location and angle) and two occupant parameters (seat position and age) were varied using a Latin hypercube design of Experiments. Four injury metrics (head injury criterion, half deflection, thoracic trauma index and pelvic force) were used to calculate injury risk. Rib fracture prediction and lung strain metrics were also analysed. As hypothesized, bullet speed had the greatest effect on each injury measure. Injury risk was reduced when bullet location was further from the B-pillar or when the bullet angle was more oblique. Age had strong c...
-
injury prediction in a side impact crash using Human Body Model simulation
Accident Analysis & Prevention, 2014Co-Authors: Adam J. Golman, Kerry A. Danelson, Logan E Miller, Joel D. StitzelAbstract:Abstract Background Improved understanding of the occupant loading conditions in real world crashes is critical for injury prevention and new vehicle design. The purpose of this study was to develop a robust methodology to reconstruct injuries sustained in real world crashes using vehicle and Human Body finite element Models. Methods A real world near-side impact crash was selected from the Crash Injury Research and Engineering Network (CIREN) database. An average sedan was struck at approximately the B-pillar with a 290 degree principal direction of force by a lightweight pickup truck, resulting in a maximum crush of 45 cm and a crash reconstruction derived Delta-V of 28 kph. The belted 73-year-old midsized female driver sustained severe thoracic injuries, serious brain injuries, moderate abdominal injuries, and no pelvic injury. Vehicle finite element Models were selected to reconstruct the crash. The bullet vehicle parameters were heuristically optimized to match the crush profile of the simulated struck vehicle and the case vehicle. The Total Human Model for Safety (THUMS) midsized male finite element Model of the Human Body was used to represent the case occupant and reconstruct her injuries using the head injury criterion (HIC), half deflection, thoracic trauma index (TTI), and pelvic force to predict injury risk. A variation study was conducted to evaluate the robustness of the injury predictions by varying the bullet vehicle parameters. Results The THUMS thoracic injury metrics resulted in a calculated risk exceeding 90% for AIS3+ injuries and 70% risk of AIS4+ injuries, consistent with her thoracic injury outcome. The THUMS Model predicted seven rib fractures compared to the case occupant's 11 rib fractures, which are both AIS3 injuries. The pelvic injury risk for AIS2+ and AIS3+ injuries were 37% and 2.6%, respectively, consistent with the absence of pelvic injury. The THUMS injury prediction metrics were most sensitive to bullet vehicle location. The maximum 95% confidence interval width for the mean injury metrics was only 5% demonstrating high confidence in the THUMS injury prediction. Conclusions This study demonstrates a variation study methodology in which Human Body Models can be reliably used to robustly predict injury probability consistent with real world crash injury outcome.
Marie-christine Chevalier - One of the best experts on this subject based on the ideXlab platform.
-
Effect of anthropometry scaling on the response of the piper child scalable Human Body Model subject to pelvic impact
Journal of Biomechanics, 2020Co-Authors: Marie-christine Chevalier, Philippe BeillasAbstract:The Open Source PIPER child scalable Human Body Model was publicly released in April 2017 (www.piper-project.org) along with frontal and side impact validation conditions. The objective of this paper is to investigate the effect of anthropometry scaling on the response of the Model in side pelvic impact. Three setups from two published studies were used: (1) a lateral drop test (2) a greater trochanter impact with a rigid pendulum (3) a pelvis side impact with a flat surface. The first study used scaling assumption developed for crash test dummy design (setups 1 and 2) and the second performed tests on post mortem Human surrogates. The baseline 6 years old child Model was scaled using a Model morphing methodology to match the stature and weight of the surrogates used in the two published studies. Overall, the main trends observed in the three setups can be approached using the baseline Model. Although the Model morphing did not account for specific skeletal dimensions, it reduced some of the discrepancies between Model response and reference for the drop test and flat plate impact. However, it had little effect on the pendulum test. In that case, the Model response was in the corridor at low speed but above at higher speeds. Possible reasons for this difference should be further investigated.
-
Side impact applications of the PIPER scalable child Human Body Model
2017Co-Authors: Philippe Beillas, Anicet Le Ruyet, Marie-christine ChevalierAbstract:The PIPER scalable child Human Body Model was recently released. It is scalable as a function of stature/age within the PIPER software. While several applications have been performed in frontal impact as new versions of the Model were developed, no side impact applications have been reported up to now. The objectives of the current study were to investigate the usability of the PIPER child Model and software for side impact through two applications related to the effect of anthropometric variations. In the first application, the pelvic region validation setup from Ouyang et al. (2003) was investigated using five subject specific Models. The anthropometric variations were found to partially explain the experimental variability. In the second application, the extreme anthropometric range possibly represented by the Q3 dummy in the regulation R129 was studied. A large effect was also observed on the response in simplified side impact simulations. The results should be considered as preliminary considering some of the statistical and setup assumptions made to build the extreme Models. However, the methodology that was developed could be used with different assumptions to refine the extreme Models, and these could be use in the future to check the CRS dynamic behaviour not only for dummy dimensions but for the complete range of anthropometry a dummy is covering.
Svein Kleiven - One of the best experts on this subject based on the ideXlab platform.
-
performances of the piper scalable child Human Body Model in accident reconstruction
PLOS ONE, 2017Co-Authors: Chiara Giordano, Svein KleivenAbstract:Human Body Models (HBMs) have the potential to provide significant insights into the pediatric response to impact. This study describes a scalable/posable approach to perform child accident reconstructions using the Position and Personalize Advanced Human Body Models for Injury Prediction (PIPER) scalable child HBM of different ages and in different positions obtained by the PIPER tool. Overall, the PIPER scalable child HBM managed reasonably well to predict the injury severity and location of the children involved in real-life crash scenarios documented in the medical records. The developed methodology and workflow is essential for future work to determine child injury tolerances based on the full Child Advanced Safety Project for European Roads (CASPER) accident reconstruction database. With the workflow presented in this study, the open-source PIPER scalable HBM combined with the PIPER tool is also foreseen to have implications for improved safety designs for a better protection of children in traffic accidents.
Seungbok Choi - One of the best experts on this subject based on the ideXlab platform.
-
an adaptive fuzzy sliding mode control of magneto rheological seat suspension with Human Body Model
Journal of Intelligent Material Systems and Structures, 2016Co-Authors: Do Kyun Shin, Do Xuan Phu, Sangmin Choi, Seungbok ChoiAbstract:This article presents the control performances of a vehicle seat suspension system equipped with magneto-rheological dampers using a new adaptive fuzzy sliding mode controller. A magneto-rheological damper is designed by applying the Bingham Model incorporating with the field-dependent rheological properties of magneto-rheological fluid. On the other hand, a seat suspension Model is established by integrating with a 4-degree-of-freedom Human Body Model. Then, the governing equations are then derived considering the vertical motion of the seat. Subsequently, an adaptive fuzzy controller is formulated by considering the acceleration of the seat. This controller is combined with the sliding mode controller to ensure the robustness against Model uncertainty and external disturbances. The controller is then evaluated through experiment. It is demonstrated that the proposed seat suspension system realized by the proposed adaptive fuzzy sliding mode controller can provide very effective ride comfort performances...
-
vibration control of electrorheological seat suspension with Human Body Model using sliding mode control
Journal of Sound and Vibration, 2007Co-Authors: Seungbok Choi, Youngmin HanAbstract:This paper presents vibration control performance of a semi-active electrorheological (ER) seat suspension system using a robust sliding mode controller (SMC). A cylindrical type of ER seat damper is manufactured for a commercial vehicle seat suspension and its field-dependent damping force is experimentally evaluated. A vertical vibration Model of Human-Body is then derived and integrated with the governing equations of the ER seat suspension system. The integrated seat-driver Model featured by a high order degree-of-freedom (dof) is reduced through a balanced Model reduction method. The SMC is then designed based on the reduced Model and the state observer is formulated to estimate feedback states which cannot be directly measured from sensors. By imposing a semi-active actuating condition, the synthesized SMC is experimentally realized. In the experimental implementation, a driver directly sits on the controlled seat. Both vertical displacement and acceleration are measured at seat frame and driver's head, respectively. Control performances are evaluated under various road conditions and compared with those obtained from conventional passive seat suspension system.