Assessment of Pelvis and Upper Leg Injury Risk in Car-Pedestrian Collisions: Comparison of Accident Statistics, Impactor Tests and a Human Body Finite Element Model

Author(s):  
Jess G. Snedeker ◽  
Markus H. Muser ◽  
Felix H. Walz
Author(s):  
X. G. Tan ◽  
R. Kannan ◽  
Andrzej J. Przekwas

Until today the modeling of human body biomechanics poses many great challenges because of the complex geometry and the substantial heterogeneity of human body. We developed a detailed human body finite element model in which the human body is represented realistically in both the geometry and the material properties. The model includes the detailed head (face, skull, brain, and spinal cord), the skeleton, and air cavities (including the lung). Hence it can be used to accurately acquire the stress wave propagation in the human body under various loading conditions. The blast loading on the human surface was generated from the simulated C4 blast explosions, via a novel combination of 1-D and 3-D numerical formulations. We used the explicit finite element solver in the multi-physics code CoBi for the human body biomechanics. This is capable of solving the resulting large system containing millions of unknowns in an extremely scalable fashion. The meshes generated for these simulations are of good quality. This enables us to employ relatively large time step sizes, without resorting to the artificial time scaling treatment. In order to study the human body dynamic response under the blast loading, we also developed an interface to apply the blast pressure loading on the external human body surface. These newly developed models were used to conduct parametric simulations to find out the brain biomechanical response when the blasts impact the human body. Under the same blast loading we also show the differences of brain response when having different material properties for the skeleton, the existence of other body parts such as torso.


Author(s):  
Raed E. El-Jawahri ◽  
Jesse S. Ruan ◽  
Stephen W. Rouhana ◽  
Saeed D. Barbat

The Ford Motor Company Human Body Finite Element Model (FHBM) was validated against rib dynamic tension and 3-point bending tests. The stress-strain and moment-strain data from the tension and bending simulations respectively were compared with human rib specimen test data. The model used represented a 50th percentile adult male. It was used to compare chest deflection and chest acceleration as thoracic injury indicator in blunt impact and belted occupants in front sled impact simulations. A 150 mm diameter of 23.4 kg impactor was used in the blunt impact simulations with impact speeds of 2, 4, and 8 m/s. In the Front sled impact simulations, single-step acceleration pulses with peaks of 10, 20, and 30 g were used. The occupants were restrained by 3-point belt system, however neither pretensioner nor shoulder belt force limiter were used. The external force, head acceleration, chest deflection, chest acceleration, and the maximum values of Von Mises stress and plastic strain were the model outputs. The results showed that the external contact force, head acceleration, chest deflection, and chest acceleration in the blunt impact simulations varied between 1.5–7 kN, 5–28 g, 18–80 mm, and 8–40 g respectively. The same responses varied between 7–24 kN, 13–40 g, 15–50 mm, and 16–46 g respectively in the front sled impact simulations. The maximum Von Mises stress and plastic strain were 50–127 MPa, and 0.04–2% respectively in the blunt impact simulations and 72–134 MPa, and 0.13–3% respectively in the sled impact simulations.


2016 ◽  
Vol 16 (08) ◽  
pp. 1640018 ◽  
Author(s):  
MICHÈLE BODO ◽  
SÉBASTIEN ROTH

This study deals with free fall accident analysis involving adults, and their numerical replications using a finite element model of the human thorax. The main purpose is to determine the role of body position at impact in the thorax injury risk appearance. For this study, cases of real-world free-fall provided by an emergency department were selected and investigated. These cases involved both male and female with an age range of 20 to 63 years, who sustained accidental free-fall with both injured and uninjured cases. The examination of the patients' medical record provided helpful information to accurately perform numerical replications with the finite element model HUByx (Hermaphrodite Universal Biomechanical yx model) which was already validated for various experimental tests in the field of automobile, ballistic impacts and blast. The results of simulations at different impact location allowed highlighting the crucial influence of the body orientation in the risk of thoracic injury occurrence.


Human spine is one of the complex structure of the human body. It provides the link between upper and lower extremities of the human body. It is estimated that at least 30% of people in the middle age group from thirty to fifty years have some degree of disc degeneration. Disc degeneration disease can affect the quality of life and in certain individual it can cause severe chronic pain if left untreated. The low back pain associated with lumbar disc degeneration is usually generated from two causes which are abnormal motion instability and inflammation. Abnormal motion instability occurs when the annulus fibrosus are worn down and cannot absorb stress on the human spine effectively resulting in changes in movements along the vertebral segment. To understand lumbar disc problem, a thorough knowledge of the biomechanics of the normal human lumbar spine and a disc degenerated lumbar spine is of great importance. In this study, Computed tomography image of a 33 year old male is used. A three dimensional (3D) human lumbar spine (L3 to L5) is created and validated with literature. The finite element model was modified to degenerated disc and studied the biomechanics of the lumbar spine. Comparison of the biomechanics of normal human lumbar spine is done with the human lumbar spine with disc degeneration for different range of motion and different loads. The result shows that the pressure generated on degenerated disc is greater than normal disc. This work can be implemented and used for designing implants and also for intervertebral disc related analysis


2019 ◽  
Vol 20 (3) ◽  
pp. 445-453 ◽  
Author(s):  
Wansoo Pak ◽  
Yunzhu Meng ◽  
Jeremy Schap ◽  
Bharath Koya ◽  
Scott F. Gayzik ◽  
...  

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