A Finite Element Investigation of a Functional Spine Unit in Conjunction With a Multi-Body Model of the Lumbar Spine for Impact Dynamics

Volume 2 ◽  
2004 ◽  
Author(s):  
Volkan Esat ◽  
Memis Acar
Keyword(s):  
Finite Element ◽  
Lumbar Spine ◽  
Reaction Force ◽  
Element Model ◽  
Fe Model ◽  
Body Model ◽  
Spine Model ◽  
Spinal Segments ◽  
Whole Spine ◽  
Multi Body

In this study, the finite element (FE) technique was used in conjunction with multi-body modelling to simulate and analyse the dynamic behaviour of the spinal segments in order to investigate the effects of impact loadings on the lumbar spine. A 3-D multi-body model of the lumbar spine and an FE model of the L2-L3 motion segment were developed. Both models were validated for flexion and compression loadings, showing good agreements with a previously validated lumbar spine model. The predictions of the multi-body model under dynamic impact loading conditions such as reaction forces at lumbar motion segments were employed as force boundary conditions for the finite element model of the selected functional spine unit (FSU). Stress and pressure in the intervertebral disc element and the reaction force at a specific vertebral level were presented. This approach has the potential to more realistically simulate the dynamics of spinal segments and whole spine, and study the effects on spinal elements.

A Biomechanical Model of Lumbar Spine

2000 ◽  
Author(s):  
Subramanya Uppala ◽  
Robert X. Gao ◽  
Scott Cowan ◽  
K. Francis Lee
Keyword(s):  
Finite Element ◽  
Lumbar Spine ◽  
Experimental Studies ◽  
Three Dimensional ◽  
Biomechanical Model ◽  
Element Model ◽  
Fe Model ◽  
Flexion Extension ◽  
Cortical Shell ◽  
Three Dimensional Finite Element

Abstract The strength and stability of the lumbar spine are determined not only by the bone and muscles, but also by the visco-elastic structures and the interplay between the different components of the spine, such as ligaments, capsules, annulus fibrosis, and articular cartilage. In this paper we present a non-linear three-dimensional Finite Element model of the lumbar spine. Specifically, a three-dimensional FE model of the L4-5 one-motion segment/2 vertebrae was developed. The cortical shell and the cancellous bone of the vertebral body were modeled as 3D isoparametric eight-nodal elements. Finite element models of spinal injuries with fixation devices are also developed. The deformations across the different sections of the spine are observed under the application of axial compression, flexion/extension, and lateral bending. The developed FE models provided input to both the fixture design and experimental studies.

Development and Preliminary Validation of a 50th Percentile Pedestrian Finite Element Model

2015 ◽  
Author(s):  
Costin D. Untaroiu ◽  
Jacob B. Putnam ◽  
Jeremy Schap ◽  
Matt L. Davis ◽  
F. Scott Gayzik
Keyword(s):  
Finite Element ◽  
Lumbar Spine ◽  
Test Data ◽  
Element Model ◽  
Human Model ◽  
Whole Body ◽  
Fe Model ◽  
Pedestrian Protection ◽  
Bending Tests ◽  
Impact Tests

Pedestrians represent one of the most vulnerable road users and comprise nearly 22% of the road crash related fatalities in the world. Therefore, protection of pedestrians in the car-to-pedestrian collisions (CPC) has recently generated increased attention with regulations which involve three subsystem tests for adult pedestrian protection (leg, thigh and head impact tests). The development of a finite element (FE) pedestrian model could be a better alternative 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 preliminarily validate a FE model corresponding to a 50th male pedestrian in standing posture. The FE model mesh and defined material properties are based on the Global Human Body Modeling (GHBMC) 50th percentile male occupant model. The lower limb-pelvis and lumbar spine regions of the human model were preliminarily validated against the post mortem human surrogate (PMHS) test data recorded in four-point lateral knee bending tests, pelvic impact tests, and lumbar spine bending tests. Then, pedestrian-to-vehicle impact simulations were performed using the whole pedestrian model and the results were compared to corresponding pedestrian PMHS tests. Overall, the preliminary simulation results showed that lower leg response is close to the upper boundaries of PMHS corridors. The pedestrian kinematics predicted by the model was also in the overall range of test data obtained with PMHS with various anthropometries. In addition, the model shows capability to predict the most common 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.

Simulation of the Transverse Fractures of the Sacrum Using a Finite Element Model of Lumbar Spine-Pelvis Segment

2008 ◽  
Author(s):  
A. Ivanov ◽  
A. Kiapour ◽  
N. Ebraheim ◽  
V. K. Goel
Keyword(s):  
Finite Element ◽  
Lumbar Spine ◽  
Finite Element Model ◽  
Treatment Options ◽  
Element Model ◽  
Severe Trauma ◽  
Fe Model ◽  
Element Analysis ◽  
Modern Computer ◽  
Transverse Fractures

The sacrum fractures are very severe trauma which frequently accompanied with lumbar spine fractures. The surgical procedures often require primary stabilization of both lumbar spine and sacrum. To understand the rationale of the instrumentation numerous cadaveric studies were conducted to elucidate the anatomy of fractures and treatment options [1,2,3]. The modern computer technology allowed simulating the fractures and repairing using the Finite Element Analysis, also [4,5]. The last method has a raw of advantages versus cadaveric method such as higher reliability, accuracy, and safety. Finite element investigations of the pelvic fractures allowed comparing the influence of implants on pelvis stability. However, the extensive search of the literature failed to find a finite element model which includes the pelvis and lumbar spine together. Current study is the first step to accomplish this goal. An experimentally validated model of ligamentous lumbar spine was combined with the FE model of pelvis [7], and simulation of the sacrum fractures was conducted.

Numerical Analysis of Vehicle Occupant Responses during Rear Impact Using a Human Body Model

2014 ◽  
Vol 566 ◽  
pp. 480-485 ◽  
Author(s):  
Jonas A. Pramudita ◽  
Shunsuke Kikuchi ◽  
Yuji Tanabe
Keyword(s):  
Finite Element ◽  
Numerical Analysis ◽  
Finite Element Model ◽  
Real World ◽  
Element Model ◽  
Vehicle Occupant ◽  
Body Model ◽  
Rear Impact ◽  
Multi Body ◽  
Impact Simulations

Understanding vehicle occupant responses during real-world rear collision accidents is very important in the development of appropriate safety technologies for neck injury lessening. In this study, numerical analysis of vehicle occupant responses during rear impact were conducted by using a human multi-body model, a seat finite element model and crash accelerations obtained from real-world accidents. The human multi-body model was developed based on the body characteristics of a typical Japanese male, including the outer body geometry, inertial properties of body segments and passive joint characteristics. The seat finite element model was extracted from a detailed car finite element model. A small modification was done to the seat model to deal with the rear impact simulations. The crash accelerations were obtained from the drive recorder database of rear collision accidents occurred in Japan. Several crash accelerations were selected and used as input conditions during the rear impact simulations. Kinematic responses of the occupants during the accidents can be reasonably predicted by the simulations. Furthermore, different level of accelerations leads to different kinematics responses that may cause variation in injury occurrence and injury severity.

Multi-Purpose Flexible Bodies Integration Into the Multi-Body System of a Metro-Vehicle

2010 ◽  
Author(s):  
Guido Saporito ◽  
Alessandro Baroni ◽  
Mario Romani
Keyword(s):  
Finite Element ◽  
Element Model ◽  
The Body ◽  
Fe Model ◽  
Body System ◽  
Bogie Frame ◽  
Flexible Bodies ◽  
Multi Body ◽  
The Finite Element Model ◽  
Analytical Verification

The work points to study the effects of bodies flexibility concerning the Running Dynamics and Structural requirements and how such aspects could be integrated into a single design process of a mass transit vehicle in terms of Comfort, Safety, Track fatigue and Bogie-frame design. The multi-body system of the vehicle has been developed. The finite element model of the flexible bodies as car-body, wheel-set, bolster-beam and bogie-frame have been implemented. The critical but necessary step, in the integration process of the flexible body into a multi-body system, is the reduction of the finite element model of the body. For that reason an analytical verification in focused to validate the reduced FE-model with respect to the full FE-model has been thought, developed and implemented to provide a useful design tool; such an analytical verification aids the engineer to control and to optimize the reduction technique applied to the full-FE-model of the body. The validation procedure, which has been implemented, consists in developing an alter for the DMAP, Direct Matrix Abstraction Program of the FE-solver, and processing the output into a programming environment.

scholarly journals A Constitutive Model for the Annulus of Human Intervertebral Disc: Implications for Developing a Degeneration Model and Its Influence on Lumbar Spine Functioning

2014 ◽  
Vol 2014 ◽  
pp. 1-15 ◽  
Author(s):  
J. Cegoñino ◽  
V. Moramarco ◽  
A. Calvo-Echenique ◽  
C. Pappalettere ◽  
A. Pérez del Palomar
Keyword(s):  
Finite Element ◽  
Lumbar Spine ◽  
Intervertebral Disc ◽  
Annulus Fibrosus ◽  
Porous Matrix ◽  
Intervertebral Discs ◽  
Nonlinear Material ◽  
Theoretical Modelling ◽  
Fe Model ◽  
Spine Model

The study of the mechanical properties of the annulus fibrosus of the intervertebral discs is significant to the study on the diseases of lumbar intervertebral discs in terms of both theoretical modelling and clinical application value. The annulus fibrosus tissue of the human intervertebral disc (IVD) has a very distinctive structure and behaviour. It consists of a solid porous matrix, saturated with water, which mainly contains proteoglycan and collagen fibres network. In this work a mathematical model for a fibred reinforced material including the osmotic pressure contribution was developed. This behaviour was implemented in a finite element (FE) model and numerical characterization and validation, based on experimental results, were carried out for the normal annulus tissue. The characterization of the model for a degenerated annulus was performed, and this was capable of reproducing the increase of stiffness and the reduction of its nonlinear material response and of its hydrophilic nature. Finally, this model was used to reproduce the degeneration of the L4L5 disc in a complete finite element lumbar spine model proving that a single level degeneration modifies the motion patterns and the loading of the segments above and below the degenerated disc.

scholarly journals Validation of Finite Element Model by Smart Aggregate-Based Stress Monitoring

Sensors ◽  
2018 ◽  
Vol 18 (11) ◽  
pp. 4062 ◽  
Author(s):  
Haibin Zhang ◽  
Shuang Hou ◽  
Jinping Ou
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
Lateral Displacement ◽  
Concrete Strength ◽  
Reaction Force ◽  
Element Model ◽  
Fe Model ◽  
Stress Monitoring ◽  
Monitoring Method ◽  
Smart Aggregate

Concrete compressive strength is an important parameter of material properties for assessing seismic performance of reinforced concrete (RC) structures, which has a certain level of uncertainty due to its inherent variability. In this paper, the method of concrete strength validation of finite element model using smart aggregate (SA)-based stress monitoring is proposed. The FE model was established using Open System for Earthquake Engineering Simulation (OpenSEES) platform. The concrete strengths obtained from the material test, peak stress of SA, and estimated concrete strength based on SA stress were employed in FE models. The lateral displacement monitored by Liner variable differential transformer and vertical axial load monitored by load cell in the experiment are applied in the model. By comparing the global response (i.e., lateral reaction force and hysteretic loop), local response (i.e., concrete stress, rebar strain, and cross-section moment) and corresponding root-mean-square error obtained from experiment and numerical analysis, the capabilities of validation of FE model using SA-based stress monitoring method were demonstrated.

A Finite Element Model of a Midsize Male for Simulating Pedestrian Accidents

2017 ◽  
Vol 140 (1) ◽  
Author(s):  
Costin D. Untaroiu ◽  
Wansoo Pak ◽  
Yunzhu Meng ◽  
Jeremy Schap ◽  
Bharath Koya ◽  
...  
Keyword(s):  
Finite Element ◽  
Lumbar Spine ◽  
Element Model ◽  
Human Model ◽  
Whole Body ◽  
Fe Model ◽  
Bending Tests ◽  
Lower Extremity Injuries ◽  
Pedestrian Accidents ◽  
Extremity Injuries

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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