Airbag deployments are associated with loud noise of short duration, called impulse noise. Research on impulse noise from weapons firing, in particular that of G.R. Price & J.T. Kalb of the United States Army Research Laboratory, has led to the development of a mathematical model of the ear. This model incorporates transfer functions which alter the incident sound pressure through various ear parts. It also calculates a function, called the "hazard": a measure of mechanical fatigue of the hair cells in the inner ear. In this study, the repeatability of the model was examined by comparing its predictive behaviour for airbag noise impulses generated by nominally identical airbag systems. Calculations of potential "hazard" made by the model were also examined for reasonableness based on mechanical and biomechanical considerations. A large number of airbag noise pulses were examined using the model. The results provide some counter-intuitive insights into the mechanism of noise-induced hearing loss from deployment of airbag systems. Based upon testing of feline subjects (which are believed to be a good indicator of the risk to the more susceptible segment of the human population), the results indicate the following: there could be a risk of temporary and possible permanent threshold shifts in approximately 67% of the 1990-1995 model year vehicles from 19 manufacturers which were tested and assessed using the human ear model. For Part I see IRRD 879203. For the covering abstract of the conference see IRRD E201429.
{"title":"INVESTIGATION INTO THE NOISE ASSOCIATED WITH AIRBAG DEPLOYMENT: PART II--INJURY RISK STUDY USING A MATHEMATICAL MODEL OF THE HUMAN EAR","authors":"S. Rouhana, S. Webb, Vaundle C. Dunn","doi":"10.4271/983162","DOIUrl":"https://doi.org/10.4271/983162","url":null,"abstract":"Airbag deployments are associated with loud noise of short duration, called impulse noise. Research on impulse noise from weapons firing, in particular that of G.R. Price & J.T. Kalb of the United States Army Research Laboratory, has led to the development of a mathematical model of the ear. This model incorporates transfer functions which alter the incident sound pressure through various ear parts. It also calculates a function, called the \"hazard\": a measure of mechanical fatigue of the hair cells in the inner ear. In this study, the repeatability of the model was examined by comparing its predictive behaviour for airbag noise impulses generated by nominally identical airbag systems. Calculations of potential \"hazard\" made by the model were also examined for reasonableness based on mechanical and biomechanical considerations. A large number of airbag noise pulses were examined using the model. The results provide some counter-intuitive insights into the mechanism of noise-induced hearing loss from deployment of airbag systems. Based upon testing of feline subjects (which are believed to be a good indicator of the risk to the more susceptible segment of the human population), the results indicate the following: there could be a risk of temporary and possible permanent threshold shifts in approximately 67% of the 1990-1995 model year vehicles from 19 manufacturers which were tested and assessed using the human ear model. For Part I see IRRD 879203. For the covering abstract of the conference see IRRD E201429.","PeriodicalId":291036,"journal":{"name":"Publication of: Society of Automotive Engineers","volume":"9 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1998-11-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116839835","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Reid T. Miller, S. Margulies, M. Leoni, M. Nonaka, Xiao‐Han Chen, Douglas H. Smith, D. Meaney
Traumatic brain injury (TBI) finite element (FE) analyses have evolved from crude geometric representations of the skull and brain system into sophisticated models which take into account distinct anatomical features. Two distinct FE modeling approaches have evolved to account for the relative motion that occurs between the skull and cerebral cortex during TBI. The first approach assumes that the relative motion can be estimated by representing the cerebrospinal fluid inside the subarachnoid space as a low shear modulus, virtually incompressible solid. The second approach assumes that the relative motion can be approximated by defining a frictional interface between the cerebral cortex and dura mater. This study presents data from an experimental model of TBI coupled with FE analyses to evaluate the modeling approach's ability to predict specific forms of TBI. Axial plane rotational accelerations produced prolonged traumatic coma in the miniature pig, axonal injury throughout regions of the white matter, and macroscopic hemorrhagic cortical contusions. Results from 2-dimensional FE analyses of the miniature pig showed that the manner in which the modeling approach accounts for the relative motions occurring between the skull and cerebral cortex can dramatically influence the outcome of an analysis. This study clearly demonstrated that the modeling approach which represented the relative motion between the skull and cerebral cortex as a frictional interface best predicted the resulting injury pattern in a 5th axial plane animal experiment.
{"title":"FINITE ELEMENT MODELING APPROACHES FOR PREDICTING INJURY IN AN EXPERIMENTAL MODEL OF SEVERE DIFFUSE AXONAL INJURY","authors":"Reid T. Miller, S. Margulies, M. Leoni, M. Nonaka, Xiao‐Han Chen, Douglas H. Smith, D. Meaney","doi":"10.4271/983154","DOIUrl":"https://doi.org/10.4271/983154","url":null,"abstract":"Traumatic brain injury (TBI) finite element (FE) analyses have evolved from crude geometric representations of the skull and brain system into sophisticated models which take into account distinct anatomical features. Two distinct FE modeling approaches have evolved to account for the relative motion that occurs between the skull and cerebral cortex during TBI. The first approach assumes that the relative motion can be estimated by representing the cerebrospinal fluid inside the subarachnoid space as a low shear modulus, virtually incompressible solid. The second approach assumes that the relative motion can be approximated by defining a frictional interface between the cerebral cortex and dura mater. This study presents data from an experimental model of TBI coupled with FE analyses to evaluate the modeling approach's ability to predict specific forms of TBI. Axial plane rotational accelerations produced prolonged traumatic coma in the miniature pig, axonal injury throughout regions of the white matter, and macroscopic hemorrhagic cortical contusions. Results from 2-dimensional FE analyses of the miniature pig showed that the manner in which the modeling approach accounts for the relative motions occurring between the skull and cerebral cortex can dramatically influence the outcome of an analysis. This study clearly demonstrated that the modeling approach which represented the relative motion between the skull and cerebral cortex as a frictional interface best predicted the resulting injury pattern in a 5th axial plane animal experiment.","PeriodicalId":291036,"journal":{"name":"Publication of: Society of Automotive Engineers","volume":"5 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1998-11-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133922079","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Two-dimensional film analysis was conducted to study the kinematics of the head and neck of 17 restrained human volunteers in 24 frontal impacts for acceleration levels from 6 to 15g. The trajectory of the head center-of-gravity relative to upper torso reference points and the rotation of the head and neck relative to the lower torso during the forward motion phase were of particular interest. The purpose of this study was to analyze the head-neck kinematics in the mid-sagittal plane for a variety of human volunteer frontal sled tests from different laboratories using a common analysis method for all tests. The study also sought to define a common response corridor for the trajectory of the head center-of-gravity from those tests.
{"title":"Head-neck kinematics in dynamic forward flexion","authors":"B. Deng, J. Melvin, S. Rouhana","doi":"10.4271/983156","DOIUrl":"https://doi.org/10.4271/983156","url":null,"abstract":"Two-dimensional film analysis was conducted to study the kinematics of the head and neck of 17 restrained human volunteers in 24 frontal impacts for acceleration levels from 6 to 15g. The trajectory of the head center-of-gravity relative to upper torso reference points and the rotation of the head and neck relative to the lower torso during the forward motion phase were of particular interest. The purpose of this study was to analyze the head-neck kinematics in the mid-sagittal plane for a variety of human volunteer frontal sled tests from different laboratories using a common analysis method for all tests. The study also sought to define a common response corridor for the trajectory of the head center-of-gravity from those tests.","PeriodicalId":291036,"journal":{"name":"Publication of: Society of Automotive Engineers","volume":"2006 24","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1998-11-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"120847771","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
E. Lizée, S. Robin, E. Song, N. Bertholon, J. L. Coz, B. Besnault, F. Lavaste
Even though computational techniques are now very common in automotive safety engineering, there is still a need for further development of biofidelic tools for assessing human responses in crash situations. The authors of this paper designed a 3D finite element model of the human body and constituted a large experimental database for the purpose of validation. The geometry of the seated 50th percentile adult male was chosen for the model. The number of elements used to represent the anatomy was limited to 10,000. Material laws come from existing literature and when necessary, parameter identification processes were used. Special attention was paid to the constitution of the validation database. Boundary conditions and results from most of the available cadaver and volunteer experiments were analyzed. More than 30 test configurations were selected, including sled, impactor, and belt compression tests with a wide range of energy levels and in frontal, lateral, and oblique directions. 120+ corridors were derived and integrated into the development of the validation phase. The model behavior was evaluated in the light of a set of impacts in a vehicle environment. The validation database is described in detail and correlation obtained between model responses and experimental results is shown. Uses of the model are discussed.
{"title":"DEVELOPMENT OF A 3D FINITE ELEMENT MODEL OF THE HUMAN BODY","authors":"E. Lizée, S. Robin, E. Song, N. Bertholon, J. L. Coz, B. Besnault, F. Lavaste","doi":"10.4271/983152","DOIUrl":"https://doi.org/10.4271/983152","url":null,"abstract":"Even though computational techniques are now very common in automotive safety engineering, there is still a need for further development of biofidelic tools for assessing human responses in crash situations. The authors of this paper designed a 3D finite element model of the human body and constituted a large experimental database for the purpose of validation. The geometry of the seated 50th percentile adult male was chosen for the model. The number of elements used to represent the anatomy was limited to 10,000. Material laws come from existing literature and when necessary, parameter identification processes were used. Special attention was paid to the constitution of the validation database. Boundary conditions and results from most of the available cadaver and volunteer experiments were analyzed. More than 30 test configurations were selected, including sled, impactor, and belt compression tests with a wide range of energy levels and in frontal, lateral, and oblique directions. 120+ corridors were derived and integrated into the development of the validation phase. The model behavior was evaluated in the light of a set of impacts in a vehicle environment. The validation database is described in detail and correlation obtained between model responses and experimental results is shown. Uses of the model are discussed.","PeriodicalId":291036,"journal":{"name":"Publication of: Society of Automotive Engineers","volume":"13 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1998-11-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126808836","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
In frontal automobile collisions, the driver's foot is usually stepping on the brake pedal as a pre-collision instinctive response. The tensile force generated in the Achilles tendon produces a compressive preload on the tibia. If the toe board intrudes after the crash, additional external force is applied to the driver's foot. Using human cadaveric specimens, a series of dynamic impact tests were conducted to investigate the combined effect of muscle preloading and external force. A constant tendon force was applied to the forefoot by a rigid pendulum. Preloading the tibia greatly increased the tibial axial force and the combination of these forces resulted in 5 tibial pylon fractures out of 16 specimens. This loading condition could be one of the mechanisms of tibial pylon fracture which is rated as one of the severest forms in lower leg injuries and which was difficult to reproduce in the laboratory. A finite element model was used to visualize stress distribution in the foot and ankle complex. The boundary conditions in the model were carefully defined to simulate the cadaver test. The force-time history and stress distribution in the ankle were computed and the effect of the tendon force acting in concert with an external axial load was studied. In the presence of a tendon force, the stress was found to be higher in the tibia and lower in the calcaneus.
{"title":"A Severe Ankle and Foot Injury in Frontal Crashes and Its Mechanism","authors":"Y. Kitagawa, H. Ichikawa, A. King, R. Levine","doi":"10.4271/983145","DOIUrl":"https://doi.org/10.4271/983145","url":null,"abstract":"In frontal automobile collisions, the driver's foot is usually stepping on the brake pedal as a pre-collision instinctive response. The tensile force generated in the Achilles tendon produces a compressive preload on the tibia. If the toe board intrudes after the crash, additional external force is applied to the driver's foot. Using human cadaveric specimens, a series of dynamic impact tests were conducted to investigate the combined effect of muscle preloading and external force. A constant tendon force was applied to the forefoot by a rigid pendulum. Preloading the tibia greatly increased the tibial axial force and the combination of these forces resulted in 5 tibial pylon fractures out of 16 specimens. This loading condition could be one of the mechanisms of tibial pylon fracture which is rated as one of the severest forms in lower leg injuries and which was difficult to reproduce in the laboratory. A finite element model was used to visualize stress distribution in the foot and ankle complex. The boundary conditions in the model were carefully defined to simulate the cadaver test. The force-time history and stress distribution in the ankle were computed and the effect of the tendon force acting in concert with an external axial load was studied. In the presence of a tendon force, the stress was found to be higher in the tibia and lower in the calcaneus.","PeriodicalId":291036,"journal":{"name":"Publication of: Society of Automotive Engineers","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1998-11-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123166719","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
King H. Yang, F. Zhu, F. Luan, Longmao Zhao, P. Begeman
A 3-dimensional finite element model of a human neck was developed to study the mechanics of cervical spine while subjected to impacts. The neck geometry was obtained from MRI scans of a 50th percentile male volunteer. This model consisting of vertebrae C1-T1 was constructed primarily of 8-node brick elements. Vertebrae were modeled using linear elastic-plastic materials and the intervertebral discs were modeled using linear viscoelastic materials. Sliding interfaces were defined to simulate the motion of synovial facet joints. A previously developed head and brain model was also incorporated. Only the passive effects of the head and neck muscles were considered. Data from head drop tests performed at Duke University and data from 3, 24 km/hr cadaver rear-end impact sled tests were used to validate the model. The validated model was integrated into a skeleton torso model previously developed to simulate a 50th percentile male driver in a 48 km/hr impact with a pre-deployed airbag. This simulation was similar to that reported by Cheng et al. In this application, the kinematics and airbag pressure predicted by the model compared with experimental data. None of the airbags used in the simulations or experiments represent any currently in production. Further research is still needed to fully validate the model before it can be used to study neck loads during head-airbag or other serious injury interactions.
{"title":"DEVELOPMENT OF A FINITE ELEMENT MODEL OF THE HUMAN NECK","authors":"King H. Yang, F. Zhu, F. Luan, Longmao Zhao, P. Begeman","doi":"10.4271/983157","DOIUrl":"https://doi.org/10.4271/983157","url":null,"abstract":"A 3-dimensional finite element model of a human neck was developed to study the mechanics of cervical spine while subjected to impacts. The neck geometry was obtained from MRI scans of a 50th percentile male volunteer. This model consisting of vertebrae C1-T1 was constructed primarily of 8-node brick elements. Vertebrae were modeled using linear elastic-plastic materials and the intervertebral discs were modeled using linear viscoelastic materials. Sliding interfaces were defined to simulate the motion of synovial facet joints. A previously developed head and brain model was also incorporated. Only the passive effects of the head and neck muscles were considered. Data from head drop tests performed at Duke University and data from 3, 24 km/hr cadaver rear-end impact sled tests were used to validate the model. The validated model was integrated into a skeleton torso model previously developed to simulate a 50th percentile male driver in a 48 km/hr impact with a pre-deployed airbag. This simulation was similar to that reported by Cheng et al. In this application, the kinematics and airbag pressure predicted by the model compared with experimental data. None of the airbags used in the simulations or experiments represent any currently in production. Further research is still needed to fully validate the model before it can be used to study neck loads during head-airbag or other serious injury interactions.","PeriodicalId":291036,"journal":{"name":"Publication of: Society of Automotive Engineers","volume":"2 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1998-11-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127592527","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Data is currently lacking to define the state of skeletal muscle properties within the cadaver. This study sought to define changes in the postmortem properties of skeletal muscle as a function of mechanical loading and freezer storage. The tibialis anterior of the New Zealand White rabbit was chosen for study. Modulus and no-load strain were found to vary greatly from live after 8 hours postmortem. Following the dynamic changes that occur at the onset and during rigor mortis, a semi-stable region of postmortem, post-rigor properties occurred between 36 to 72 hours postmortem. A freeze-thaw process was not found to have a significant effect on the post-rigor response. The first loading cycle response of post-rigor muscle was unrepeatable but stiffer than live passive muscle. After preconditioning, the post-rigor muscle response was repeatable but significantly less stiff than live passive muscle due to an increase in no-load strain. Failure properties of postmortem muscle were found to be significantly different than live passive muscle with significant decreases in failure stress (61%) and energy (81%), while failure strain was unchanged. Results suggest that the post-rigor response of cadaver muscle is unaffected by freezing but sensitive to even a few cycles of mechanical loading.
{"title":"The effect of postmortem time and freezer storage on the mechanical properties of skeletal muscle","authors":"C. V. Ee, A. L. Chasse, B. Myers","doi":"10.4271/983155","DOIUrl":"https://doi.org/10.4271/983155","url":null,"abstract":"Data is currently lacking to define the state of skeletal muscle properties within the cadaver. This study sought to define changes in the postmortem properties of skeletal muscle as a function of mechanical loading and freezer storage. The tibialis anterior of the New Zealand White rabbit was chosen for study. Modulus and no-load strain were found to vary greatly from live after 8 hours postmortem. Following the dynamic changes that occur at the onset and during rigor mortis, a semi-stable region of postmortem, post-rigor properties occurred between 36 to 72 hours postmortem. A freeze-thaw process was not found to have a significant effect on the post-rigor response. The first loading cycle response of post-rigor muscle was unrepeatable but stiffer than live passive muscle. After preconditioning, the post-rigor muscle response was repeatable but significantly less stiff than live passive muscle due to an increase in no-load strain. Failure properties of postmortem muscle were found to be significantly different than live passive muscle with significant decreases in failure stress (61%) and energy (81%), while failure strain was unchanged. Results suggest that the post-rigor response of cadaver muscle is unaffected by freezing but sensitive to even a few cycles of mechanical loading.","PeriodicalId":291036,"journal":{"name":"Publication of: Society of Automotive Engineers","volume":"7 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1998-11-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133808004","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
As supplemental restraint system (airbag) use has increased, occasional rare injuries have occurred due to the force associated with these systems upon deployment, including forearm fractures. This study was conducted to determine the tolerance of the human forearm under a dynamic bending mode. 30 human cadaver forearm specimens were tested using 3-point bending protocol to failure at 3.3 m/s and 7.6 m/s velocities. Results indicated significantly (p<0.01) greater biomechanical parameters associated with males compared to females. The bending tolerance of the human forearm, however, was found to be most highly correlated to bone mineral density, bone area, and forearm mass. Thus, any occupant with lower bone mineral density and lower forearm geometry/mass is at higher risk. The mean failure bending moment for all specimens was 94 Nm. A smaller sized occupant with lower bone mineral density, however, has 1/2 of this tolerance (~45 Nm). The data contained in this study may be useful for design of injury-mitigating devices.
{"title":"RESPONSE AND TOLERANCE OF THE HUMAN FOREARM TO IMPACT LOADING","authors":"F. Pintar, N. Yoganandan, R. Eppinger","doi":"10.4271/983149","DOIUrl":"https://doi.org/10.4271/983149","url":null,"abstract":"As supplemental restraint system (airbag) use has increased, occasional rare injuries have occurred due to the force associated with these systems upon deployment, including forearm fractures. This study was conducted to determine the tolerance of the human forearm under a dynamic bending mode. 30 human cadaver forearm specimens were tested using 3-point bending protocol to failure at 3.3 m/s and 7.6 m/s velocities. Results indicated significantly (p<0.01) greater biomechanical parameters associated with males compared to females. The bending tolerance of the human forearm, however, was found to be most highly correlated to bone mineral density, bone area, and forearm mass. Thus, any occupant with lower bone mineral density and lower forearm geometry/mass is at higher risk. The mean failure bending moment for all specimens was 94 Nm. A smaller sized occupant with lower bone mineral density, however, has 1/2 of this tolerance (~45 Nm). The data contained in this study may be useful for design of injury-mitigating devices.","PeriodicalId":291036,"journal":{"name":"Publication of: Society of Automotive Engineers","volume":"587 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1998-11-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130588176","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
R. Happee, M. Hoofman, van den Aj Kroonenberg, P. Morsink, J. Wismans
Mathematical modelling is widely used for crash-safety research and design. However, most occupant models used in crash simulations are based on crash dummies and thereby inherit their apparent limitations. Several models simulating parts of the real human body have been published, but only few describe the entire human body and these models were developed and validated only for a limited range of conditions. This paper describes a human body model for both frontal and rearward loading. A combination of modelling techniques is applied using rigid bodies for most body segments, but describing the thorax as a flexible structure. The skin is described in detail using an arbitrary surface. Static and dynamic properties of the articulations have been derived from literature. The RAMSIS anthropometric database has been used to define a model representing a 50th percentile male. The model has been validated using volunteer tests performed at NBDL ranging from 3-15 G severity, and using established dummy biofidelity requirements for blunt thoracic impact. A satisfactory prediction has been obtained for chest deflections, head kinematics and accelerations and for kinematics and accelerations at the upper thoracic vertebra. Recommendations are given for further development and validation of the model, and for validation of models of different body sizes.
{"title":"A mathematical human body model for frontal and rearward seated automotive impact loading","authors":"R. Happee, M. Hoofman, van den Aj Kroonenberg, P. Morsink, J. Wismans","doi":"10.4271/983150","DOIUrl":"https://doi.org/10.4271/983150","url":null,"abstract":"Mathematical modelling is widely used for crash-safety research and design. However, most occupant models used in crash simulations are based on crash dummies and thereby inherit their apparent limitations. Several models simulating parts of the real human body have been published, but only few describe the entire human body and these models were developed and validated only for a limited range of conditions. This paper describes a human body model for both frontal and rearward loading. A combination of modelling techniques is applied using rigid bodies for most body segments, but describing the thorax as a flexible structure. The skin is described in detail using an arbitrary surface. Static and dynamic properties of the articulations have been derived from literature. The RAMSIS anthropometric database has been used to define a model representing a 50th percentile male. The model has been validated using volunteer tests performed at NBDL ranging from 3-15 G severity, and using established dummy biofidelity requirements for blunt thoracic impact. A satisfactory prediction has been obtained for chest deflections, head kinematics and accelerations and for kinematics and accelerations at the upper thoracic vertebra. Recommendations are given for further development and validation of the model, and for validation of models of different body sizes.","PeriodicalId":291036,"journal":{"name":"Publication of: Society of Automotive Engineers","volume":"32 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1998-11-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122507602","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Current automotive dynamic testing (ATD) positioning practices depend on seat track position, seat track travel range, and design seatback angle to determine appropriate occupant position and orientation for impact testing. In a series of studies conducted at the University of Michigan's Transportation Research Institute, driver posture and position data were collected in 44 vehicles. Seat track reference points presently used to position ATDs were found to be poor predictors of the average seat positions selected by small female, midsize male, and large male drivers. Driver-selected seatback angle was not closely related to design seatback angle, the measure currently used to orient the ATD torso. A new ATD Positioning Model was developed that more accurately represents the seated posture and position of drivers who match the ATD statutes. Seat position is specified for each adult ATD size to match the mean predicted seat position of drivers matching the ATD reference stature. ATD torso orientation is set to the average driver torso orientation. The new positioning model places the ATDs in postures/positions that are more representative of drivers of similar size.
{"title":"ATD positioning based on driver posture and position","authors":"M. Manary, M. Reed, C. Flannagan, L. Schneider","doi":"10.4271/983163","DOIUrl":"https://doi.org/10.4271/983163","url":null,"abstract":"Current automotive dynamic testing (ATD) positioning practices depend on seat track position, seat track travel range, and design seatback angle to determine appropriate occupant position and orientation for impact testing. In a series of studies conducted at the University of Michigan's Transportation Research Institute, driver posture and position data were collected in 44 vehicles. Seat track reference points presently used to position ATDs were found to be poor predictors of the average seat positions selected by small female, midsize male, and large male drivers. Driver-selected seatback angle was not closely related to design seatback angle, the measure currently used to orient the ATD torso. A new ATD Positioning Model was developed that more accurately represents the seated posture and position of drivers who match the ATD statutes. Seat position is specified for each adult ATD size to match the mean predicted seat position of drivers matching the ATD reference stature. ATD torso orientation is set to the average driver torso orientation. The new positioning model places the ATDs in postures/positions that are more representative of drivers of similar size.","PeriodicalId":291036,"journal":{"name":"Publication of: Society of Automotive Engineers","volume":"26 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1998-11-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132100265","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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