B. Besnault, F. Lavaste, H. Guillemot, S. Robin, J. L. Coz
This study describes the development of a refined finite element model (FEM) of the human pelvis. The objectives of the research work were to: (1) Statistically study the human pelvis geometry, and develop a parameterized model; (2) Mechanically validate the model with regard to the available in-house experimental data; and (3) to model the injury mechanisms observed in the experimental studies. The significant dimensions of the pelvis were identified by statistical analysis of the pelvis geometry based on the H. Reynolds et al data. Those dimensions were used to classify the in-house tested pelves. An interpolation technique was used in order to distort a reference mesh and adapt its geometry to the measured geometry of the tested pelvis. The mechanical validation of the model was carried out by comparing numerical and experimental results, and the influence of the geometrical variations on the behaviour of the pelvis was assessed. Some fracture phenomena were modeled, and the model was validated using injuries observed in experiments in terms of displacements and rupture mechanisms (beginning and propagation of the fracture). (A) For the covering abstract of the conference see IRRD E201429.
{"title":"A PARAMETRIC FINITE ELEMENT MODEL OF THE HUMAN PELVIS","authors":"B. Besnault, F. Lavaste, H. Guillemot, S. Robin, J. L. Coz","doi":"10.4271/983147","DOIUrl":"https://doi.org/10.4271/983147","url":null,"abstract":"This study describes the development of a refined finite element model (FEM) of the human pelvis. The objectives of the research work were to: (1) Statistically study the human pelvis geometry, and develop a parameterized model; (2) Mechanically validate the model with regard to the available in-house experimental data; and (3) to model the injury mechanisms observed in the experimental studies. The significant dimensions of the pelvis were identified by statistical analysis of the pelvis geometry based on the H. Reynolds et al data. Those dimensions were used to classify the in-house tested pelves. An interpolation technique was used in order to distort a reference mesh and adapt its geometry to the measured geometry of the tested pelvis. The mechanical validation of the model was carried out by comparing numerical and experimental results, and the influence of the geometrical variations on the behaviour of the pelvis was assessed. Some fracture phenomena were modeled, and the model was validated using injuries observed in experiments in terms of displacements and rupture mechanisms (beginning and propagation of the fracture). (A) For the covering abstract of the conference see IRRD E201429.","PeriodicalId":291036,"journal":{"name":"Publication of: Society of Automotive Engineers","volume":"44 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":"116475716","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}
J. Melvin, Kenneth J. Baron, W. C. Little, T. Gideon, J. Pierce
This paper describes the results of an ongoing project in the GM Motorsports Safety Technology Research Program (MSTRP) to investigate lndianapolis-type (Indy car) race car crashes using an on-board impact recorder as the primary data collection tool. The paper discusses the development of specifications for the impact-recording device, the selection of the specific recorder, and its implementation on a routine basis in Indy car racing. The results from incidents that produced significant data during the racing seasons from 1993 through the first half of 1998 are summarized. Examples of impact recordings are given which are remarkable in terms of the severity of crashes and, in most cases, the resulting lack of significant injuries. A total of 202 cases with peak decelerations above 20 G are summarized. The mean peak rigid body chassis decelerations for the sample were on the order of 53 G. Peak decelerations in excess of 60 G (some as high as 127 G) have been recorded for significant durations in many frontal, side, and rear impacts. Associated mean total velocity change was 28.3 mph for the sample. The relatively tight coupling of the driver's torso to the chassis allows direct inferences of the loads on the torso, particularly in side impacts. The data calls into question the use of chest acceleration as an injury assessment criterion in both frontal and side impacts. For the covering abstract of the conference see IRRD E201429.
{"title":"Biomechanical Analysis of Indy Race Car Crashes","authors":"J. Melvin, Kenneth J. Baron, W. C. Little, T. Gideon, J. Pierce","doi":"10.4271/983161","DOIUrl":"https://doi.org/10.4271/983161","url":null,"abstract":"This paper describes the results of an ongoing project in the GM Motorsports Safety Technology Research Program (MSTRP) to investigate lndianapolis-type (Indy car) race car crashes using an on-board impact recorder as the primary data collection tool. The paper discusses the development of specifications for the impact-recording device, the selection of the specific recorder, and its implementation on a routine basis in Indy car racing. The results from incidents that produced significant data during the racing seasons from 1993 through the first half of 1998 are summarized. Examples of impact recordings are given which are remarkable in terms of the severity of crashes and, in most cases, the resulting lack of significant injuries. A total of 202 cases with peak decelerations above 20 G are summarized. The mean peak rigid body chassis decelerations for the sample were on the order of 53 G. Peak decelerations in excess of 60 G (some as high as 127 G) have been recorded for significant durations in many frontal, side, and rear impacts. Associated mean total velocity change was 28.3 mph for the sample. The relatively tight coupling of the driver's torso to the chassis allows direct inferences of the loads on the torso, particularly in side impacts. The data calls into question the use of chest acceleration as an injury assessment criterion in both frontal and side impacts. For the covering abstract of the conference see IRRD E201429.","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":"129999707","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}
N. Yoganandan, F. Pintar, S. Kumaresan, A. Elhagediab
More data is needed to define the soft tissue components of the human cervical spine to develop and exercise mathematical analogs such as the finite element model. This study sought to determine the geometrical and biomechanical properties of spinal ligaments from the axis to the first thoracic level. 35 human cadavers were used in the study. Data were obtained for anterior and posterior longitudinal ligaments, joint capsules, ligamentum flavum, and interspinous ligament. Cryomicrotomy techniques were used to determine the geometrical characteristic. Biomechanical tests involved conducting failure tensile tests at a quasistatic rate of 10 mm/sec using in situ principles. Anterior and posterior longitudinal ligaments responded with the highest length measurements in both regions of the spine. The ligamentum flavum and joint capsules exhibited the highest area of cross-section. All ligaments demonstrated increasing cross-sectional areas in the lower cervical group compared to the mid-cervical group. Stiffness parameters were higher in the mid-cervical region than in the lower cervical region for the anterior longitudinal and interspinous ligaments and ligamentum flavum, while the reverse was true for the other ligaments. Energy was higher in the lower cervical region than in the mid-cervical region for the joint capsules, ligamentum flavum, interspinous ligament, and anterior longitudinal ligament. Anterior and longitudinal ligaments responded with the highest stress followed by the joint capsules, interspinous ligament, and ligamentum flavum. This study provides important fundamental data on the properties of human cervical spine ligaments.
{"title":"Biomechanical Assessment of Human Cervical Spine Ligaments","authors":"N. Yoganandan, F. Pintar, S. Kumaresan, A. Elhagediab","doi":"10.4271/983159","DOIUrl":"https://doi.org/10.4271/983159","url":null,"abstract":"More data is needed to define the soft tissue components of the human cervical spine to develop and exercise mathematical analogs such as the finite element model. This study sought to determine the geometrical and biomechanical properties of spinal ligaments from the axis to the first thoracic level. 35 human cadavers were used in the study. Data were obtained for anterior and posterior longitudinal ligaments, joint capsules, ligamentum flavum, and interspinous ligament. Cryomicrotomy techniques were used to determine the geometrical characteristic. Biomechanical tests involved conducting failure tensile tests at a quasistatic rate of 10 mm/sec using in situ principles. Anterior and posterior longitudinal ligaments responded with the highest length measurements in both regions of the spine. The ligamentum flavum and joint capsules exhibited the highest area of cross-section. All ligaments demonstrated increasing cross-sectional areas in the lower cervical group compared to the mid-cervical group. Stiffness parameters were higher in the mid-cervical region than in the lower cervical region for the anterior longitudinal and interspinous ligaments and ligamentum flavum, while the reverse was true for the other ligaments. Energy was higher in the lower cervical region than in the mid-cervical region for the joint capsules, ligamentum flavum, interspinous ligament, and anterior longitudinal ligament. Anterior and longitudinal ligaments responded with the highest stress followed by the joint capsules, interspinous ligament, and ligamentum flavum. This study provides important fundamental data on the properties of human cervical spine ligaments.","PeriodicalId":291036,"journal":{"name":"Publication of: Society of Automotive Engineers","volume":"16 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":"123122114","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}
C. Demetropoulos, King H. Yang, M. Grimm, T. Khalil, A. King
This study identified the mechanical properties of 10 cadaveric and 2 Hybrid III lumbar spines. Eight tests were performed on each specimen: tension, compression, anterior shear, posterior shear, left lateral shear, flexion, extension, and left lateral bending. Each test was run at a displacement rate of 100 mm/sec. The maximum displacements were selected to approximate the loading range of a 50 km/h Hybrid III dummy sled test and to be non-destructive to the specimens. Load, linear displacement, and angular displacement data were collected. Bending moment was calculated from force data. Each mode of loading demonstrated consistent characteristics. Load-displacement curves of the Hybrid III lumbar spine demonstrated an initial region of high stiffness followed by a region of constant stiffness. The exception was the tension tests, as the steel cables in the spine seemed to dominate the mechanical response in tensile loading. Loading curves of cadaveric spines demonstrated an initial region of low stiffness followed by a region of increasing stiffness, typically a feature of soft tissue response. Notable findings included the observation that the whole cadaveric lumbar spine specimens are stiffer in posterior than in anterior shear. This finding is in contrast to motion segment studies, in which the opposite trend is observed.
本研究确定了10具尸体腰椎和2具混合型腰椎的力学特性。每个标本进行8项试验:拉伸、压缩、前剪、后剪、左侧剪、屈、伸、左侧弯。每次测试都以100 mm/秒的排量进行。选择的最大位移近似于50 km/h Hybrid III假雪橇试验的加载范围，并且对试件不造成破坏。收集载荷、线性位移和角位移数据。根据受力数据计算弯矩。每种加载模式表现出一致的特性。混合型III型腰椎的载荷-位移曲线显示出一个初始高刚度区域，随后是一个恒定刚度区域。唯一的例外是拉力测试，因为脊柱中的钢索似乎主导了拉伸载荷的机械响应。尸体脊柱的加载曲线显示出一个初始的低刚度区域，随后是一个刚度增加的区域，这是软组织响应的典型特征。值得注意的发现包括观察到整个尸体腰椎标本的后切变比前切变更硬。这一发现与运动节段研究相反，在运动节段研究中观察到相反的趋势。
{"title":"MECHANICAL PROPERTIES OF THE CADAVERIC AND HYBRID III LUMBAR SPINES","authors":"C. Demetropoulos, King H. Yang, M. Grimm, T. Khalil, A. King","doi":"10.4271/983160","DOIUrl":"https://doi.org/10.4271/983160","url":null,"abstract":"This study identified the mechanical properties of 10 cadaveric and 2 Hybrid III lumbar spines. Eight tests were performed on each specimen: tension, compression, anterior shear, posterior shear, left lateral shear, flexion, extension, and left lateral bending. Each test was run at a displacement rate of 100 mm/sec. The maximum displacements were selected to approximate the loading range of a 50 km/h Hybrid III dummy sled test and to be non-destructive to the specimens. Load, linear displacement, and angular displacement data were collected. Bending moment was calculated from force data. Each mode of loading demonstrated consistent characteristics. Load-displacement curves of the Hybrid III lumbar spine demonstrated an initial region of high stiffness followed by a region of constant stiffness. The exception was the tension tests, as the steel cables in the spine seemed to dominate the mechanical response in tensile loading. Loading curves of cadaveric spines demonstrated an initial region of low stiffness followed by a region of increasing stiffness, typically a feature of soft tissue response. Notable findings included the observation that the whole cadaveric lumbar spine specimens are stiffer in posterior than in anterior shear. This finding is in contrast to motion segment studies, in which the opposite trend is observed.","PeriodicalId":291036,"journal":{"name":"Publication of: Society of Automotive Engineers","volume":"29 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":"134122392","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}
This paper describes a study in which a finite element model of the human thorax was merged with a rigid body finite element implementation of the Hybrid III dummy (after removal of the Hybrid III thorax) and the combined model used in simulations of an out-of-position driver during deployment. Parameters related to injury, such as A-P thorax deformation, Viscous Criterion, rib stress distribution, and strain in the thoracic contents were used to quantify the thoracic injury response. Initial driver position was varied to examine the relationship between distance from the airbag module and thoracic injury risk. The potential for injury mitigation by modulation of airbag inflation after initiation was also investigated. Utility of the joint model as an effective tool for analysis of occupant kinematics and dynamics, examination of injury mechanisms, and optimization of restraint system design parameters is demonstrated.
{"title":"ANALYTICAL INVESTIGATION OF DRIVER THORACIC RESPONSE TO OUT OF POSITION AIRBAG DEPLOYMENT","authors":"G. Plank, M. Kleinberger, R. Eppinger","doi":"10.4271/983165","DOIUrl":"https://doi.org/10.4271/983165","url":null,"abstract":"This paper describes a study in which a finite element model of the human thorax was merged with a rigid body finite element implementation of the Hybrid III dummy (after removal of the Hybrid III thorax) and the combined model used in simulations of an out-of-position driver during deployment. Parameters related to injury, such as A-P thorax deformation, Viscous Criterion, rib stress distribution, and strain in the thoracic contents were used to quantify the thoracic injury response. Initial driver position was varied to examine the relationship between distance from the airbag module and thoracic injury risk. The potential for injury mitigation by modulation of airbag inflation after initiation was also investigated. Utility of the joint model as an effective tool for analysis of occupant kinematics and dynamics, examination of injury mechanisms, and optimization of restraint system design parameters is demonstrated.","PeriodicalId":291036,"journal":{"name":"Publication of: Society of Automotive Engineers","volume":"14 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":"124862122","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 this chapter, from a comprehensive text about occupant and vehicle responses in rollovers, the authors report on research that tested lap belt restraints utilizing a variety of lap belt geometric and webbing slack conditions. Tests included dynamic and static tests and the use of test mannequins and human volunteers. One of the tests considered factors affecting occupant displacement and flail in motor vehicle rollover crashes. Results showed that occupant displacement from the seat in rollover conditions as affected by factors associated with a vehicle seat belt restraint system and seat. The authors conclude that design attributes that may favorably affect the performance of seat belt restraint systems for rollover protection include: mechanisms which reduce the length of webbing in the lap belt restraint system; mechanisms which increase the lap belt angle; seat and seat belt attributes which reduce the effect of occupant compliance; seat or seat cushion attributes which lower the occupant's body in the vehicle; and inclusion of passive or deployable passive mechanisms in the seat and seat belt system.
{"title":"TESTING OF SEATS AND SEAT BELTS FOR ROLLOVER PROTECTION SYSTEMS IN MOTOR VEHICLES. IN: OCCUPANT AND VEHICLE RESPONSES IN ROLLOVERS","authors":"M. Arndt","doi":"10.4271/982295","DOIUrl":"https://doi.org/10.4271/982295","url":null,"abstract":"In this chapter, from a comprehensive text about occupant and vehicle responses in rollovers, the authors report on research that tested lap belt restraints utilizing a variety of lap belt geometric and webbing slack conditions. Tests included dynamic and static tests and the use of test mannequins and human volunteers. One of the tests considered factors affecting occupant displacement and flail in motor vehicle rollover crashes. Results showed that occupant displacement from the seat in rollover conditions as affected by factors associated with a vehicle seat belt restraint system and seat. The authors conclude that design attributes that may favorably affect the performance of seat belt restraint systems for rollover protection include: mechanisms which reduce the length of webbing in the lap belt restraint system; mechanisms which increase the lap belt angle; seat and seat belt attributes which reduce the effect of occupant compliance; seat or seat cushion attributes which lower the occupant's body in the vehicle; and inclusion of passive or deployable passive mechanisms in the seat and seat belt system.","PeriodicalId":291036,"journal":{"name":"Publication of: Society of Automotive Engineers","volume":"53 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1998-09-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128828474","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}
The increased complexity of new adaptive passenger restraint systems requires implementation of a serial communication network, which connects the squibs and sensors to a central electronic module. The requirements on such a safety-critical backbone include the tolerance to serious damage of the bus wires, which may occur also during a crash event. This paper describes the concept of an in-vehicle network, combining economy, robustness and reliability with the exacting performance of high-speed multi-master communication. It requires only 2 wires for distribution of power, data, and clock in the system. The network offers real-time fault tolerance to all kinds of wiring failures, which makes this system superior to all others proposed for this application.
{"title":"Fault Tolerant Networking of Squibs and Sensors in Advanced Passenger Restraint Systems","authors":"Peter Buehring","doi":"10.4271/980353","DOIUrl":"https://doi.org/10.4271/980353","url":null,"abstract":"The increased complexity of new adaptive passenger restraint systems requires implementation of a serial communication network, which connects the squibs and sensors to a central electronic module. The requirements on such a safety-critical backbone include the tolerance to serious damage of the bus wires, which may occur also during a crash event. This paper describes the concept of an in-vehicle network, combining economy, robustness and reliability with the exacting performance of high-speed multi-master communication. It requires only 2 wires for distribution of power, data, and clock in the system. The network offers real-time fault tolerance to all kinds of wiring failures, which makes this system superior to all others proposed for this application.","PeriodicalId":291036,"journal":{"name":"Publication of: Society of Automotive Engineers","volume":"34 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1998-02-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125147667","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. Sieveka, J. Pellettiere, J. Crandall, W. Pilkey, M. Tanahashi, G. Weisenfeld, Y. Takahashi, Y. Okamoto
This paper describes a simulation model of the Hybrid III lower extremities with the 30 degree dorsiflexion ankle, developed using the Crash-Victim-Simulator/Articulated-Total-Body (CVS/ATB) program. The femur and tibia were modeled as a sequence of rigid beams with a hinge and slider at the knee. Special, locked joints were placed in the femur and tibia at the same locations as the load cells in the actual dummy. Constraint forces and moments at these joints can be compared directly to load cell data. The complex geometry of the foot was divided into 5 segments representing the heel, toe, forefoot, midfoot, and ankle regions. Two foot models were constructed: 1 barefoot and 1 with a Lehigh safety shoe. Good agreement was obtained for most parameters when single-leg pendulum tests, and full-body sled tests, were simulated using the new model.
{"title":"A New CVS/ATB Hybrid III Model for Lower Extremity Studies: Development and Validation","authors":"E. Sieveka, J. Pellettiere, J. Crandall, W. Pilkey, M. Tanahashi, G. Weisenfeld, Y. Takahashi, Y. Okamoto","doi":"10.4271/980357","DOIUrl":"https://doi.org/10.4271/980357","url":null,"abstract":"This paper describes a simulation model of the Hybrid III lower extremities with the 30 degree dorsiflexion ankle, developed using the Crash-Victim-Simulator/Articulated-Total-Body (CVS/ATB) program. The femur and tibia were modeled as a sequence of rigid beams with a hinge and slider at the knee. Special, locked joints were placed in the femur and tibia at the same locations as the load cells in the actual dummy. Constraint forces and moments at these joints can be compared directly to load cell data. The complex geometry of the foot was divided into 5 segments representing the heel, toe, forefoot, midfoot, and ankle regions. Two foot models were constructed: 1 barefoot and 1 with a Lehigh safety shoe. Good agreement was obtained for most parameters when single-leg pendulum tests, and full-body sled tests, were simulated using the new model.","PeriodicalId":291036,"journal":{"name":"Publication of: Society of Automotive Engineers","volume":"24 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1998-02-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129843379","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}
This paper compares the analytical response of a low speed, in-line vehicle impact with that of a simulated bumper test involving a rigid striker. Results from a previously validated analysis procedure indicate that a rigid pendulum mass impact test on a vehicle bumper, such as that currently mandated by the federal government, yields significantly different results from that of a typical 2-vehicle impact. This paper then proposes methods by which the existing government tests could be extended to yield additional design and analysis data that could be used to help design lower vehicle compartment loadings.
{"title":"Proposed Extensions to Federally Mandated Bumper Testing","authors":"I. Ojalvo, O. Masory","doi":"10.4271/980360","DOIUrl":"https://doi.org/10.4271/980360","url":null,"abstract":"This paper compares the analytical response of a low speed, in-line vehicle impact with that of a simulated bumper test involving a rigid striker. Results from a previously validated analysis procedure indicate that a rigid pendulum mass impact test on a vehicle bumper, such as that currently mandated by the federal government, yields significantly different results from that of a typical 2-vehicle impact. This paper then proposes methods by which the existing government tests could be extended to yield additional design and analysis data that could be used to help design lower vehicle compartment loadings.","PeriodicalId":291036,"journal":{"name":"Publication of: Society of Automotive Engineers","volume":"82 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1998-02-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124121199","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}
Lower extremity (knee) injury prediction resulting from impact trauma is presently based on a bone fracture (BF) criterion derived from experiments on predominantly aged cadavers. Subsequent experimental and theoretical studies indicate that more aged, pathological specimens require higher, rather than lower, loads to initiate BF. This suggests that a BF criterion based solely on aged specimens may not be indicative of the current driving population. In the current study, the authors sought to determine if cadaver age, physical size, sex, baseline joint pathology, or patellar geometry correlated with fracture load. An analysis was made of data from previous impact experiments conducted on 15 isolated cadaver knees using a consistent impact protocol. The protocol consisted of sequentially increasing the impact energy with a rigid interface until gross fracture. Gross BFs occurred at loads of 6.9 +/- kN (range 3.2-10.6 kN) using this protocol. Regression analyses revealed that fracture load was predicted by only 1 parameter: patellar geometry. Alternately, the authors developed a 2-D mathematical model of the human knee to explore parameters that might influence the loads required to cause gross BF. In support of the authors' recent experimental studies using rigid and padded impact interfaces, the model suggested that load intensity and it's distribution over the knee play a role in defining the fracture load as well as the site (patella or femur) of patellofemoral joint injury.
{"title":"PATELLOFEMORAL JOINT FRACTURE LOAD PREDICTION USING PHYSICAL AND PATHOLOGICAL PARAMETERS","authors":"P. Atkinson, C. M. Mackenzie, R. Haut","doi":"10.4271/980358","DOIUrl":"https://doi.org/10.4271/980358","url":null,"abstract":"Lower extremity (knee) injury prediction resulting from impact trauma is presently based on a bone fracture (BF) criterion derived from experiments on predominantly aged cadavers. Subsequent experimental and theoretical studies indicate that more aged, pathological specimens require higher, rather than lower, loads to initiate BF. This suggests that a BF criterion based solely on aged specimens may not be indicative of the current driving population. In the current study, the authors sought to determine if cadaver age, physical size, sex, baseline joint pathology, or patellar geometry correlated with fracture load. An analysis was made of data from previous impact experiments conducted on 15 isolated cadaver knees using a consistent impact protocol. The protocol consisted of sequentially increasing the impact energy with a rigid interface until gross fracture. Gross BFs occurred at loads of 6.9 +/- kN (range 3.2-10.6 kN) using this protocol. Regression analyses revealed that fracture load was predicted by only 1 parameter: patellar geometry. Alternately, the authors developed a 2-D mathematical model of the human knee to explore parameters that might influence the loads required to cause gross BF. In support of the authors' recent experimental studies using rigid and padded impact interfaces, the model suggested that load intensity and it's distribution over the knee play a role in defining the fracture load as well as the site (patella or femur) of patellofemoral joint injury.","PeriodicalId":291036,"journal":{"name":"Publication of: Society of Automotive Engineers","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1998-02-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124201125","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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