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Liu J, Liu H, Bu W, Wang Y, Xu P, Wu M, Fan Y. Effects of different helmet-mounted devices on pilot's neck injury under simulated ejection. Comput Methods Biomech Biomed Engin 2023; 26:1510-1521. [PMID: 36129013 DOI: 10.1080/10255842.2022.2124860] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2022] [Revised: 09/02/2022] [Accepted: 09/11/2022] [Indexed: 11/03/2022]
Abstract
The helmet plays an important role in protection of pilot's head and enhances the pilot's capabilities and performance significantly with the use of mounted devices such as the Night Vision Goggle (NVG). However, the use of helmet-mounted devices might increase the risk of injury due to the increased helmet weight and change in the centre of gravity of head. In this study, four helmets with different combinations of mounted devices were modelled in a validated human head-neck multi-body model to analyse their effects on the pilot's neck injury during simulated ejection. The probability of neck injury was evaluated and predicted using the N i j neck injury criteria and human injury risk curves, considering the tolerance of injury for upper and lower cervical segment. It was demonstrated that the helmet-mounted devices would increase the compression force and bending moment on cervical spine, especially for the lower cervical segments with higher N i j . In the cases with Night Vision Goggle, N i j of the lower cervical segment reached 0.54, which exceeded the requirement in aviation filed. For the cases with Visor, excessive extension occurred, resulting in a high N i j . The simulation results of this study could provide a reference for helmet and mounted devices design and offer a proposal for the protection of pilots during ejection.
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Affiliation(s)
- Jinglong Liu
- Key Laboratory for Biomechanics and Mechanobiology of Ministry of Education, Beijing Advanced Innovation Centre for Biomedical Engineering, School of Biological Science and Medical Engineering, Beihang University, Beijing, China
| | - Heqing Liu
- Air Force Medical Centre, PLA, Beijing, China
| | - Weiping Bu
- Air Force Medical Centre, PLA, Beijing, China
| | - Yawei Wang
- Key Laboratory for Biomechanics and Mechanobiology of Ministry of Education, Beijing Advanced Innovation Centre for Biomedical Engineering, School of Biological Science and Medical Engineering, Beihang University, Beijing, China
| | - Peng Xu
- Key Laboratory for Biomechanics and Mechanobiology of Ministry of Education, Beijing Advanced Innovation Centre for Biomedical Engineering, School of Biological Science and Medical Engineering, Beihang University, Beijing, China
| | - Minglei Wu
- Air Force Medical Centre, PLA, Beijing, China
| | - Yubo Fan
- Key Laboratory for Biomechanics and Mechanobiology of Ministry of Education, Beijing Advanced Innovation Centre for Biomedical Engineering, School of Biological Science and Medical Engineering, Beihang University, Beijing, China
- Key Laboratory for Biomechanics and Mechanobiology of Ministry of Education, Beijing Advanced Innovation Centre for Biomedical Engineering, School of Engineering Medicine, Beihang University, Beijing, China
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2
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Lalwala M, Koya B, Devane KS, Hsu FC, Yates KM, Newby NJ, Somers JT, Gayzik FS, Stitzel JD, Weaver AA. Effects of Standing, Upright Seated, vs. Reclined Seated Postures on Astronaut Injury Biomechanics for Lunar Landings. Ann Biomed Eng 2022; 51:951-965. [PMID: 36352272 DOI: 10.1007/s10439-022-03108-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2022] [Accepted: 10/29/2022] [Indexed: 11/11/2022]
Abstract
Astronauts may pilot a future lunar lander in a standing or upright/reclined seated posture. This study compared kinematics and injury risk for the upright/reclined (30°; 60°) seated vs. standing postures for lunar launch/landing using human body modeling across 30 simulations. While head metrics for standing and upright seated postures were comparable to 30 cm height jumps, those of reclined postures were closer to 60 cm height jumps. Head linear acceleration for 60° reclined posture in the 5 g/10 ms pulse exceeded NASA's tolerance (10.1 g; tolerance: 10 g). Lower extremity metrics exceeding NASA's tolerance in the standing posture (revised tibia index: 0.36-0.53; tolerance: 0.43) were lowered in seated postures (0.00-0.04). Head displacement was higher in standing vs. seated (9.0 cm vs. 2.4 cm forward, 7.0 cm vs. 1.3 cm backward, 2.1 cm vs. 1.2 cm upward, 7.3 cm vs. 0.8 cm downward, 2.4 cm vs. 3.2 cm lateral). Higher arm movement was seen with seated vs. standing (40 cm vs. 25 cm forward, 60 cm vs. 15 cm upward, 30 cm vs. 20 cm downward). Pulse-nature contributed more than 40% to the injury metrics for seated postures compared to 80% in the standing posture. Seat recline angle contributed about 22% to the injury metrics in the seated posture. This study established a computational methodology to simulate the different postures of an astronaut for lunar landings and generated baseline injury risk and body kinematics data.
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Affiliation(s)
- Mitesh Lalwala
- Department of Biomedical Engineering, Wake Forest School of Medicine, 575 N. Patterson Ave, Suite 530, Winston-Salem, NC, 27101, USA
- Virginia Tech-Wake Forest Center for Injury Biomechanics, 575 N. Patterson Ave, Suite 530, Winston-Salem, NC, 27101, USA
| | - Bharath Koya
- Department of Biomedical Engineering, Wake Forest School of Medicine, 575 N. Patterson Ave, Suite 530, Winston-Salem, NC, 27101, USA
- Virginia Tech-Wake Forest Center for Injury Biomechanics, 575 N. Patterson Ave, Suite 530, Winston-Salem, NC, 27101, USA
| | - Karan S Devane
- Department of Biomedical Engineering, Wake Forest School of Medicine, 575 N. Patterson Ave, Suite 530, Winston-Salem, NC, 27101, USA
- Virginia Tech-Wake Forest Center for Injury Biomechanics, 575 N. Patterson Ave, Suite 530, Winston-Salem, NC, 27101, USA
| | - Fang-Chi Hsu
- Department of Biostatistics and Data Science, Wake Forest School of Medicine, 525 Vine Street, Winston-Salem, NC, 27101, USA
| | | | | | - Jeffrey T Somers
- NASA Johnson Space Center, 2101 NASA Parkway, Houston, TX, 77058, USA
| | - F Scott Gayzik
- Department of Biomedical Engineering, Wake Forest School of Medicine, 575 N. Patterson Ave, Suite 530, Winston-Salem, NC, 27101, USA
- Virginia Tech-Wake Forest Center for Injury Biomechanics, 575 N. Patterson Ave, Suite 530, Winston-Salem, NC, 27101, USA
| | - Joel D Stitzel
- Department of Biomedical Engineering, Wake Forest School of Medicine, 575 N. Patterson Ave, Suite 530, Winston-Salem, NC, 27101, USA
- Virginia Tech-Wake Forest Center for Injury Biomechanics, 575 N. Patterson Ave, Suite 530, Winston-Salem, NC, 27101, USA
| | - Ashley A Weaver
- Department of Biomedical Engineering, Wake Forest School of Medicine, 575 N. Patterson Ave, Suite 530, Winston-Salem, NC, 27101, USA.
- Virginia Tech-Wake Forest Center for Injury Biomechanics, 575 N. Patterson Ave, Suite 530, Winston-Salem, NC, 27101, USA.
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3
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Albert DL. Variations in User Implementation of the CORA Rating Metric. STAPP CAR CRASH JOURNAL 2020; 64:1-30. [PMID: 33636001 DOI: 10.4271/2020-22-0001] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
The CORA rating metric is frequently used in the field of injury biomechanics to compare the similarity of response time histories. However, subjectivity exists within the CORA metric in the form of user-customizable parameters that give the metric the flexibility to be used for a variety of applications. How these parameters are customized is not always reported in the literature, and it is unknown how these customizations affect the CORA scores. Therefore, the purpose of this study was to evaluate how variations in the CORA parameters affect the resulting similarity scores. A literature review was conducted to determine how the CORA parameters are commonly customized within the literature. Then, CORA scores for two datasets were calculated using the most common parameter customizations and the default parameters. Differences between the CORA scores using customized and default parameters were statistically significant for all customizations. Furthermore, most customizations produced score increases relative to the default settings. The use of standard deviation corridors and exclusion of the corridor component were found to produce the largest score differences. The observed differences demonstrated the need for researchers to exercise transparency when using customized parameters in CORA analyses.
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Affiliation(s)
- Devon L Albert
- Center for Injury Biomechanics, Department of Biomedical Engineering and Mechanics, Virginia Tech
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4
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Meng Y, Hu W, Untaroiu C. An examination of the performance of damaged energy-absorbing end terminals. ACCIDENT; ANALYSIS AND PREVENTION 2020; 147:105789. [PMID: 33007743 DOI: 10.1016/j.aap.2020.105789] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/05/2020] [Revised: 09/05/2020] [Accepted: 09/14/2020] [Indexed: 06/11/2023]
Abstract
OBJECTIVES Guardrail end terminals are designed to gradually decelerate vehicles during impact and protect vehicle occupants from severe injuries. It has been observed that some in-service end terminals are damaged, and it is unclear if their safety performance is still acceptable. The objectives of this study were to examine the conditions of in-service end terminals, and to evaluate the performance of damaged relative to undamaged end terminals in simulated impacts. METHODS Common damage patterns of guardrail end terminals were investigated by using post-crash pictures collected from the National Automotive Sampling System-Crashworthiness Data System (NASS-CDS). Conditions of in-service end terminals mounted along roads in portions of six U.S. states were examined by using a sample from the second Strategic Highway Research Program-Roadway Information Database (SHRP2-RID). Finite Element (FE) models of two minorly and three severely damaged ET-Plus systems, a commonly used energy-absorbing guardrail end terminal along U.S. roads, were developed. To evaluate the performance of the damaged ET-Plus systems, we performed impact simulations with vehicle-to-damaged ET-Plus models according to the National Cooperative Highway Research Program (NCHRP) 350, test conditions 3-30. RESULTS Of the 1000 in-service end terminal cases we investigated, 73% were undamaged, 18% had minor damage, and 8% had major damage. Increases in the average vehicle deceleration rates, maximum vehicle yaw angles, and vehicle local deformations were observed in simulated impacts with damaged ET-Plus end terminals relative to impacts with undamaged ET-Plus end terminals. For one damaged ET-Plus, a secondary collision was observed. Overall, we found that the damaged end terminals usually increased collision severity when compared with undamaged end terminals. CONCLUSIONS The findings of this study point out the need for in-service performance evaluations and proper maintenance and repair practices of end terminals. The simulation models developed in this study could be further employed to investigate device performance in crash situations that are physically impractical to test and investigate the effects of site characteristics on device performance. The simulation models could also supplement crash tests to certify new hardware designs.
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Affiliation(s)
- Yunzhu Meng
- Department of Biomedical Engineering and Mechanics, Virginia Tech, United States
| | - Wen Hu
- Insurance Institute for Highway Safety, United States
| | - Costin Untaroiu
- Department of Biomedical Engineering and Mechanics, Virginia Tech, United States.
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Meng Y, Untaroiu C. Numerical investigation of occupant injury risks in car-to-end terminal crashes using dummy-based injury criteria and vehicle-based crash severity metrics. ACCIDENT; ANALYSIS AND PREVENTION 2020; 145:105700. [PMID: 32777560 DOI: 10.1016/j.aap.2020.105700] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/22/2020] [Revised: 06/28/2020] [Accepted: 07/21/2020] [Indexed: 06/11/2023]
Abstract
Guardrails were designed to deter vehicle access to off-road areas and consequently prevent hitting rigid fixed objects alongside the road (e.g. trees, utility poles, traffic barriers, etc.). However, guardrails cause 10 % of deaths in vehicle-to-fixed-object crashes, which recently attracted attention in the highway safety community on the vehicle-based injury criteria used in regulations. The objectives of this study were to investigate both full-body and body-region driver injury probabilities using finite element (FE) simulations, to quantify the influence of pre-impact conditions on injury probabilities, and to analyze the relationship between the vehicle-based crash severity metrics currently used in regulations and the injury probabilities assessed using dummy-based injury criteria. A total of 20 FE impact simulations between a car (Toyota Yaris) with a Hybrid III M50 dummy model in the driver seat and an end terminal model (ET-Plus) were performed in various configurations (e.g. pre-impact velocities, offsets, and angles). The driver's risk of serious injuries (AIS 3+) was estimated based on kinematic and kinetic responses of the dummy during the crashes. A non-linear regression approach was used to compare the injury probabilities assessed in this study to the vehicle-based crash severity metrics used in the testing regulations. In particular, the US Manual for Assessing Safety Hardware (MASH) guideline and European procedures (EN1317) were used for the study. All the recorded dummy-based injury criteria values pass the Federal Motor Vehicle Safety Standard (FMVSS) 208 limits which indicated a low driver risk of serious injury. Overall, the pre-impact vehicle velocity showed to have the highest influence in almost all injury probabilities (59 %, 79 %, 62 %, and 44 % in full-body, head, neck, and chest injuries, respectively). The offset between vehicle midline and the guardrail barrier was the most important variable for thigh injuries (56 %). The assessed injury probabilities were compared to vehicle-based severity metrics. The full-body and chest injuries showed the highest correlation with Occupant Impact Velocity (OIV), Acceleration Severity Index (ASI), and Theoretical Head Impact Velocity (THIV) (R2 > 0.6). Lower correlations of thigh injuries were recorded to OIV (R2 = 0.59) and THIV (R2 = 0.46). Meanwhile, weak correlations were observed between all the other regressions which indicated that no vehicle-based criteria could be used to predict head and neck injuries. Car-to-end terminal crash FE simulations involving a dummy model were performed for the first time in this study. The results pointed out the limitations of the standard vehicle-based injury methods in terms of head and neck injury prediction. The dummy-based injury assessment methodology presented in this study could supplement the crash tests for various impact conditions. In addition, the models could be used to design new advanced guardrail end terminals.
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Affiliation(s)
- Yunzhu Meng
- Department of Biomedical Engineering and Mechanics, Virginia Tech, Blacksburg, VA, USA
| | - Costin Untaroiu
- Department of Biomedical Engineering and Mechanics, Virginia Tech, Blacksburg, VA, USA.
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6
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Ye X, Jones DA, Gaewsky JP, Koya B, McNamara KP, Saffarzadeh M, Putnam JB, Somers JT, Gayzik FS, Stitzel JD, Weaver AA. Lumbar Spine Response of Computational Finite Element Models in Multidirectional Spaceflight Landing Conditions. J Biomech Eng 2020; 142:051007. [PMID: 31701120 PMCID: PMC7105154 DOI: 10.1115/1.4045401] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2019] [Revised: 10/30/2019] [Indexed: 11/08/2022]
Abstract
The goals of this study are to compare the lumbar spine response variance between the hybrid III, test device for human occupant restraint (THOR), and global human body models consortium simplified 50th percentile (GHBMC M50-OS) finite element models and evaluate the sensitivity of lumbar spine injury metrics to multidirectional acceleration pulses for spaceflight landing conditions. The hybrid III, THOR, and GHBMC models were positioned in a baseline posture within a generic seat with side guards and a five-point restraint system. Thirteen boundary conditions, which were categorized as loading condition variables and environmental variables, were included in the parametric study using a Latin hypercube design of experiments. Each of the three models underwent 455 simulations for a total of 1365 simulations. The hybrid III and THOR models exhibited similar lumbar compression forces. The average lumbar compression force was 45% higher for hybrid III (2.2 ± 1.5 kN) and 51% higher for THOR (2.0 ± 1.6 kN) compared to GHBMC (1.3 ± 0.9 kN). Compared to hybrid III, THOR sustained an average 64% higher lumbar flexion moment and an average 436% higher lumbar extension moment. The GHBMC model sustained much lower bending moments compared to hybrid III and THOR. Regressions revealed that lumbar spine responses were more sensitive to loading condition variables than environmental variables across all models. This study quantified the intermodel lumbar spine response variations and sensitivity between hybrid III, THOR, and GHBMC. Results improve the understanding of lumbar spine response in spaceflight landings.
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Affiliation(s)
- Xin Ye
- Center for Injury Biomechanics, Wake Forest University School of Medicine,
Virginia-Tech Wake Forest University 575 N. Patterson Avenue, Suite 120, Winston-Salem, NC 27101
e-mail:
| | - Derek A. Jones
- Center for Injury Biomechanics, Wake Forest University School of Medicine,
Virginia-Tech Wake Forest University, 575 N. Patterson Avenue, Suite 120, Winston-Salem, NC 27101
e-mail:
| | - James P. Gaewsky
- Center for Injury Biomechanics, Wake Forest University School of Medicine,
Virginia-Tech Wake Forest University, 575 N. Patterson Avenue, Suite 120, Winston-Salem, NC 27101
e-mail:
| | - Bharath Koya
- Center for Injury Biomechanics, Wake Forest University School of Medicine,
Virginia-Tech Wake Forest University, 575 N. Patterson Avenue, Suite 120, Winston-Salem, NC 27101
e-mail:
| | - Kyle P. McNamara
- Center for Injury Biomechanics, Wake Forest University School of Medicine,
Virginia-Tech Wake Forest University, 575 N. Patterson Avenue, Suite 120, Winston-Salem, NC 27101
e-mail:
| | - Mona Saffarzadeh
- Center for Injury Biomechanics, Wake Forest University School of Medicine,
Virginia-Tech Wake Forest University, 575 N. Patterson Avenue, Suite 120, Winston-Salem, NC 27101
e-mail:
| | - Jacob B. Putnam
- NASA Langley Research Center, 1 NASA Dr., Hampton, VA 23666
e-mail:
| | | | - F. Scott Gayzik
- Center for Injury Biomechanics, Wake Forest University School of Medicine,
Virginia-Tech Wake Forest University, 575 N. Patterson Avenue, Suite 120, Winston-Salem, NC 27101
e-mail:
| | - Joel D. Stitzel
- Center for Injury Biomechanics, Wake Forest University School of Medicine,
Virginia-Tech Wake Forest University, 575 N. Patterson Avenue, Suite 120, Winston-Salem, NC 27101
e-mail:
| | - Ashley A. Weaver
- Center for Injury Biomechanics, Wake Forest University School of Medicine,
Virginia-Tech Wake Forest University, 575 N. Patterson Avenue, Suite 120, Winston-Salem, NC 27101
e-mail:
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7
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Jones D, Gaewsky J, Saffarzadeh M, Putnam J, Weaver A, Somers J, Stitzel JD. Multi-Direction Validation of a Finite Element 50th Percentile Male Hybrid III Anthropomorphic Test Device for Spaceflight Applications. J Biomech Eng 2018; 141:2712944. [PMID: 30383185 DOI: 10.1115/1.4041906] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2018] [Indexed: 11/08/2022]
Abstract
The use of anthropomorphic test devices (ATDs) for calculating injury risk of occupants in spaceflight scenarios is crucial for ensuring the safety of crewmembers. Finite element (FE) modeling of ATDs reduces cost and time in the design process. The objective of this study was to validate a Hybrid III ATD FE model using a multi-direction test matrix for future spaceflight configurations. 25 Hybrid III physical tests were simulated using a 50th percentile male Hybrid III FE model. The sled acceleration pulses were approximately half-sine shaped, and can be described as a combination of peak acceleration and time to reach peak (rise time). The range of peak accelerations was 10-20G, and the rise times were 30-110 ms. Test directions were frontal (-GX), rear (GX), vertical (-GZ), and lateral (-GY). Simulation responses were compared to physical tests using the CORrelation and Analysis (CORA) method. Correlations were very good to excellent and the order of best average response by direction was -GX (0.916±0.020), GZ (0.860±0.116), GX (0.829±0.112), and finally GY (0.804±0.053). Qualitative and quantitative results demonstrated the model was sufficiently validated for spaceflight configuration modeling and simulation.
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Affiliation(s)
- Derek/A Jones
- Wake Forest University School of Medicine, Virginia-Tech Wake Forest University Center for Injury Biomechanics, 575 N. Patterson Ave, Suite 120, Winston-Salem, NC 27101
| | - James Gaewsky
- Wake Forest University School of Medicine, Virginia-Tech Wake Forest University Center for Injury Biomechanics, 575 N. Patterson Ave, Suite 120, Winston-Salem, NC 27101
| | - Mona Saffarzadeh
- Wake Forest University School of Medicine, Virginia-Tech Wake Forest University Center for Injury Biomechanics, 575 N. Patterson Ave, Suite 120, Winston-Salem, NC 27101
| | | | - Ashley Weaver
- Wake Forest University School of Medicine, Virginia-Tech Wake Forest University Center for Injury Biomechanics, 575 N. Patterson Ave, Suite 120, Winston-Salem, NC 27101
| | | | - Joel D Stitzel
- Wake Forest University School of Medicine, Virginia-Tech Wake Forest University Center for Injury Biomechanics, 575 N. Patterson Ave, Suite 120, Winston-Salem, NC 27101
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8
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McNamara KP, Jones DA, Gaewsky JP, Putnam JB, Somers JT, Weaver AA, Stitzel JD. Validation of a Finite Element 50th Percentile THOR Anthropomorphic Test Device in Multiple Sled Test Configurations. STAPP CAR CRASH JOURNAL 2018; 62:415-442. [PMID: 30609003 DOI: 10.4271/2018-22-0012] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
Computational models of anthropomorphic test devices (ATDs) can be used in crash simulations to quantify the injury risks to occupants in both a cost-effective and time-sensitive manner. The purpose of this study was to validate the performance of a 50th percentile THOR finite element (FE) model against a physical THOR ATD in 11 unique loading scenarios. Physical tests used for validation were performed on a Horizontal Impact Accelerator (HIA) where the peak sled acceleration ranged from 8-20 G and the time to peak acceleration ranged from 40-110 ms. The directions of sled acceleration relative to the THOR model consisted of -GX (frontal impact), +GY (left-sided lateral impact), and +GZ (downward vertical impact) orientations. Simulation responses were compared to physical tests using the CORrelation and Analysis (CORA) method. Using a weighted method, the average response and standard error by direction was +GY (0.83±0.03), -GX (0.80±0.01), and +GZ (0.76±0.03). Qualitative and quantitative results demonstrated the FE model's kinetics and kinematics were sufficiently validated against its counterpart physical model in the tested loading directions.
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Affiliation(s)
- Kyle P McNamara
- Wake Forest School of Medicine, Virginia Tech - Wake Forest University Center for Injury Biomechanics
| | - Derek A Jones
- Wake Forest School of Medicine, Virginia Tech - Wake Forest University Center for Injury Biomechanics
| | - James P Gaewsky
- Wake Forest School of Medicine, Virginia Tech - Wake Forest University Center for Injury Biomechanics
| | | | | | - Ashley A Weaver
- Wake Forest School of Medicine, Virginia Tech - Wake Forest University Center for Injury Biomechanics
| | - Joel D Stitzel
- Wake Forest School of Medicine, Virginia Tech - Wake Forest University Center for Injury Biomechanics
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9
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Abellán-López D, Sánchez-Lozano M, Martínez-Sáez L. Frontal crashworthiness characterisation of a vehicle segment using curve comparison metrics. ACCIDENT; ANALYSIS AND PREVENTION 2018; 117:136-144. [PMID: 29702331 DOI: 10.1016/j.aap.2018.04.017] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/30/2017] [Revised: 02/28/2018] [Accepted: 04/13/2018] [Indexed: 06/08/2023]
Abstract
The objective of this work is to propose a methodology for the characterization of the collision behaviour and crashworthiness of a segment of vehicles, by selecting the vehicle that best represents that group. It would be useful in the development of deformable barriers, to be used in crash tests intended to study vehicle compatibility, as well as for the definition of the representative standard pulses used in numerical simulations or component testing. The characterisation and selection of representative vehicles is based on the objective comparison of the occupant compartment acceleration and barrier force pulses, obtained during crash tests, by using appropriate comparison metrics. This method is complemented with another one, based exclusively on the comparison of a few characteristic parameters of crash behaviour obtained from the previous curves. The method has been applied to different vehicle groups, using test data from a sample of vehicles. During this application, the performance of several metrics usually employed in the validation of simulation models have been analysed, and the most efficient ones have been selected for the task. The methodology finally defined is useful for vehicle segment characterization, taken into account aspects of crash behaviour related to the shape of the curves, difficult to represent by simple numerical parameters, and it may be tuned in future works when applied to larger and different samples.
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Affiliation(s)
- D Abellán-López
- Mechanical Engineering and Energy Department, Universidad Miguel Hernández de Elche, Av. Universitat sn, 03202, Elche, Spain
| | - M Sánchez-Lozano
- Mechanical Engineering and Energy Department, Universidad Miguel Hernández de Elche, Av. Universitat sn, 03202, Elche, Spain.
| | - L Martínez-Sáez
- University Institute for Automobile Research (INSIA), Universidad Politécnica de Madrid, Carretera de Valencia (A-3), km 7, 28031, Madrid, Spain
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10
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Untaroiu CD, Pak W, Meng Y, Schap J, Koya B, Gayzik S. A Finite Element Model of a Midsize Male for Simulating Pedestrian Accidents. J Biomech Eng 2017; 140:2653833. [DOI: 10.1115/1.4037854] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2017] [Indexed: 11/08/2022]
Abstract
Pedestrians represent one of the most vulnerable road users and comprise nearly 22% the road crash-related fatalities in the world. Therefore, protection of pedestrians in car-to-pedestrian collisions (CPC) has recently generated increased attention with regulations involving three subsystem tests. The development of a finite element (FE) pedestrian model could provide a complementary component that characterizes the whole-body response of vehicle–pedestrian interactions and assesses the pedestrian injuries. The main goal of this study was to develop and to validate a simplified full body FE model corresponding to a 50th male pedestrian in standing posture (M50-PS). The FE model mesh and defined material properties are based on a 50th percentile male occupant model. The lower limb-pelvis and lumbar spine regions of the human model were validated against the postmortem human surrogate (PMHS) test data recorded in four-point lateral knee bending tests, pelvic\abdomen\shoulder\thoracic impact tests, and lumbar spine bending tests. Then, a pedestrian-to-vehicle impact simulation was performed using the whole pedestrian model, and the results were compared to corresponding PMHS tests. Overall, the simulation results showed that lower leg response is mostly within the boundaries of PMHS corridors. In addition, the model shows the capability to predict the most common lower extremity injuries observed in pedestrian accidents. Generally, the validated pedestrian model may be used by safety researchers in the design of front ends of new vehicles in order to increase pedestrian protection.
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Affiliation(s)
- Costin D. Untaroiu
- Department of Biomedical Engineering and Mechanics, Virginia Tech, Blacksburg, VA 24060 e-mail:
| | - Wansoo Pak
- Department of Biomedical Engineering and Mechanics, Virginia Tech, Blacksburg, VA 24060
| | - Yunzhu Meng
- Department of Biomedical Engineering and Mechanics, Virginia Tech, Blacksburg, VA 24060
| | - Jeremy Schap
- Department of Biomedical Engineering, Wake Forest University School of Medicine, Winston-Salem, NC 27101
| | - Bharath Koya
- Department of Biomedical Engineering, Wake Forest University School of Medicine, Winston-Salem, NC 27101
| | - Scott Gayzik
- Department of Biomedical Engineering, Wake Forest University School of Medicine, Winston-Salem, NC 27101
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11
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Baker WA, Untaroiu CD, Crawford DM, Chowdhury MR. Mechanical characterization and finite element implementation of the soft materials used in a novel anthropometric test device for simulating underbody blast loading. J Mech Behav Biomed Mater 2017; 74:358-364. [PMID: 28668593 DOI: 10.1016/j.jmbbm.2017.06.021] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2017] [Revised: 06/16/2017] [Accepted: 06/19/2017] [Indexed: 11/15/2022]
Abstract
Soft materials (e.g. polymers) are widely used in biomechanical devices to represent the nonlinear viscoelastic properties inherent in biological soft tissues. Knowledge of their mechanical properties is used to inform design choices and develop accurate finite element (FE) models of human surrogates. The goal of this study was to characterize the behavior of eight polymeric materials used in the design of a novel anthropomorphic test device (ATD) and implement these materials in an FE model of the ATD. Tensile and compressive tests at strain rates ranging from 0.01s-1 to 1000s-1 were conducted on specimens from each material. Stress-strain relationships at discrete strain rates were used to define strain rate-dependent hyper-elastic material models in a commercial finite element solver. Then, the material models were implemented into an FE model of the ATD. The performance of the material models in the FE model was evaluated by simulating experiments that were conducted on the ATD lower limb. The material characterization tests revealed viscoelastic strain rate-dependent properties in the flesh and compliant elements of the ATD. Higher modulus polymers exhibited rate-dependent, strain-hardening properties. A strong agreement was seen between the material model simulations and corresponding experiments. In component simulations, the materials performed well and the model reasonably predicted the forces observed in experiments.
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Affiliation(s)
- Wade A Baker
- Virginia Tech, Department of Biomedical Engineering and Mechanics, Center for Injury Biomechanics, 2280 Kraft Drive, Blacksburg, VA 24061, United States.
| | - Costin D Untaroiu
- Virginia Tech, Department of Biomedical Engineering and Mechanics, Center for Injury Biomechanics, 2280 Kraft Drive, Blacksburg, VA 24061, United States.
| | - Dawn M Crawford
- United States Army Research Laboratory, WIAMan Engineering Office, APG, MD, 2800 Powder Mill Road, Adelphi, MD 20783-1138, United States
| | - Mostafiz R Chowdhury
- United States Army Research Laboratory, WIAMan Engineering Office, APG, MD, 2800 Powder Mill Road, Adelphi, MD 20783-1138, United States
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Yates KM, Lu YC, Untaroiu CD. Statistical shape analysis of the human spleen geometry for probabilistic occupant models. J Biomech 2016; 49:1540-1546. [DOI: 10.1016/j.jbiomech.2016.03.027] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2015] [Revised: 02/22/2016] [Accepted: 03/17/2016] [Indexed: 11/25/2022]
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