Development and Validation of a Finite Element Model of the Lower Limb

2004 ◽  
Author(s):  
Costin Untaroiu ◽  
Kurosh Darvish ◽  
Jeff Crandall ◽  
Bing Deng ◽  
J. T. Wang
Keyword(s):  
Finite Element ◽  
Lower Limb ◽  
Model Development ◽  
Fe Model ◽  
Lateral Impact ◽  
Hexahedral Elements ◽  
Limb Injuries ◽  
Bend Tests ◽  
Point Bend ◽  
Validation Tests

Pedestrians struck by a vehicle frequently sustain lower limb injuries. Moreover, the biomechanics of the lower limb under lateral impact influences the trajectory of the pedestrian and subsequent injuries to the pelvis, thorax, and head. In order to increase the understanding of injury mechanisms in the lower limb, a finite element (FE) model of the lower limb was developed. The geometry of the bones and flesh was originally obtained from the Visible Human Project Database and was scaled to a 50th percentile male. The geometry of the knee ligaments was originally obtained from the 3D-CAD-Browser Database and was scaled according to the published anatomical data to align with the bones and the corresponding insertion sites. The FE mesh consists mostly of hexahedral elements which was developed using a structural mesh generator. The material and failure properties were initially selected from the literature and were later tuned based on the validation tests. The FE model was validated using the literature data and several cadaveric component tests performed specifically for model development and evaluation. The validation tests included quasi-static and dynamic lateral three-point-bend tests of the femur and the leg with flesh, and lateral four-point-bend tests of the knee joint.

Development and Validation of an In-Vivo Finite Element Pelvis Model With Cortical Thickness Mapped From a Cadaver

2011 ◽  
Author(s):  
Young Ho Kim ◽  
Jong-Eun Kim ◽  
Alan W. Eberhardt
Keyword(s):  
Finite Element ◽  
Motor Vehicle ◽  
Human Subjects ◽  
Model Development ◽  
Biomechanical Properties ◽  
Fe Model ◽  
Lateral Impact ◽  
Vehicle Accidents ◽  
Pelvis Fracture

Pelvis fracture and associated injuries from motor vehicle accidents or falls are often life threatening [1]. Cadaveric experiments and finite element (FE) models have been widely used to investigate biomechanical properties, structural responses, and injury tolerances of the pelvis. In FE model development, the geometry of the bone structures is commonly constructed from computed tomography (CT) scans of cadavers. The use of live human subjects, however, has been limited due to low CT resolution resulting from mandatory low radiation doses and involuntary movements of the subject. The Global Human Body Models Consortium (GHBMC) elected to use a living 50th percentile male for its full body FE model development; however, cortical bone thickness was not accurately imaged for the pelvis, where it is believed to play an important role in absorbing strain energy during lateral impact [2].

Finite Element Analysis of the Distributed Vibration Absorbers for Structural Noise Control

2005 ◽  
Author(s):  
Ashwini Gautam ◽  
Chris Fuller ◽  
James Carneal
Keyword(s):  
Finite Element ◽  
Numerical Model ◽  
Base Plate ◽  
Element Model ◽  
Fe Model ◽  
Vibration Absorbers ◽  
Element Analysis ◽  
Poroelastic Media ◽  
Hexahedral Elements ◽  
Component Models

This work presents an extensive analysis of the properties of distributed vibration absorbers (DVAs) and their effectiveness in controlling the sound radiation from the base structure. The DVA acts as a distributed mass absorber consisting of a thin metal sheet covering a layer of acoustic foam (porous media) that behaves like a distributed spring-mass-damper system. To assess the effectiveness of these DVAs in controlling the vibration of the base structures (plate) a detailed finite elements model has been developed for the DVA and base plate structure. The foam was modeled as a poroelastic media using 8 node hexahedral elements. The structural (plate) domain was modeled using 16 degree of freedom plate elements. Each of the finite element models have been validated by comparing the numerical results with the available analytical and experimental results. These component models were combined to model the DVA. Preliminary experiments conducted on the DVAs have shown an excellent agreement between the results obtained from the numerical model of the DVA and from the experiments. The component models and the DVA model were then combined into a larger FE model comprised of a base plate with the DVA treatment on its surface. The results from the simulation of this numerical model have shown that there has been a significant reduction in the vibration levels of the base plate due to DVA treatment on it. It has been shown from this work that the inclusion of the DVAs on the base plate reduces their vibration response and therefore the radiated noise. Moreover, the detailed development of the finite element model for the foam has provided us with the capability to analyze the physics behind the behavior of the distributed vibration absorbers (DVAs) and to develop more optimized designs for the same.

Automated Segmentation of Swine Skulls for Finite Element Model Creation Using High Resolution μ-CT Images

2019 ◽  
Vol 16 (03) ◽  
pp. 1842012 ◽  
Author(s):  
Zimo Zhu ◽  
Donna C. Jones ◽  
G. R. Liu ◽  
Sajjad Soleimani ◽  
Xu Huang ◽  
...  
Keyword(s):  
Finite Element ◽  
Material Properties ◽  
Complex Structure ◽  
Model Development ◽  
Element Model ◽  
Fe Model ◽  
Micro Computed Tomography ◽  
Mineral Density ◽  
Detailed Model ◽  
Bone Mineral Density Loss

Finite element (FE) analysis has been widely used to investigate bone responses to mechanical loading. Research in long bones has been straight forward because modeling of these bones requires only two material properties. Such an FE model may provide an adequate approximation of the anatomy for many cases. However, a more detailed model of skull bones is needed to accurately capture its complex structure of multiple bone pieces and the various mineral densities distributed throughout these bone pieces. Unfortunately, FE model development incorporating both complex geometries and anatomically accurate material properties is both computationally and labor intensive. In this study, a method is proposed to automatically segment micro-computed tomography ([Formula: see text]-CT) scan images of bone pieces to build an FE model of a full swine hemi-skull. Using the Digital Imaging and Communications in Medicine (DICOM) files from scanned bones, the complete geometry of each bone piece is recreated through seven customized processing algorithms. After assembling the bone pieces to form the skull, experimentally derived Young’s modulus values are correlated to grayscale values to produce a detailed FE model for accurate simulation. This detailed skull model can be used to predict strain/stress patterns in response to various loading regimes to facilitate research questions in fracture healing and growth, as well as bone tissue engineering and bone mineral density loss (e.g., osteoporosis).

A Finite Element Model of the Occupant Lower Extremity for Automotive Impact Applications

2012 ◽  
Author(s):  
Costin D. Untaroiu ◽  
Neng Yue ◽  
Jaeho Shin
Keyword(s):  
Finite Element ◽  
Lower Extremity ◽  
Lower Limb ◽  
Traffic Accidents ◽  
Element Model ◽  
Lower Limb Injuries ◽  
Moderate Severity ◽  
Injury Mechanisms ◽  
Limb Injuries ◽  
Life Threatening

Although not life-threatening, lower limb injuries are the most frequent injury of moderate severity (AIS 2), sustained in a vehicle crash (Pattimore et al., 1991). To better understand the injury mechanisms, several lower extremity (LEX) finite element (FE) models were developed to investigate traffic accidents involving occupants in vehicles (Yang et al., 2006). The main limitations of existing lower limb FE models are due to their geometries, the modeling approaches used to represent their components, and limited test data used for the model validation.

Finite Element Analysis of Nonlinear Water Wave-Body Interaction: Computational Issues

2012 ◽  
Author(s):  
C. P. Vendhan ◽  
P. Sunny Kumar ◽  
P. Krishnankutty
Keyword(s):  
Finite Element ◽  
Free Surface ◽  
Water Waves ◽  
Water Wave ◽  
Large Body ◽  
Boundary Integral ◽  
Body Motion ◽  
Fe Model ◽  
Computational Domain ◽  
Hexahedral Elements

Design of floating structures exposed to water waves often requires nonlinear analysis because of high wave steepness and large body motion. In this context, Mixed Eulerian-Lagrangian (MEL) methods for nonlinear water wave problems based on the potential flow theory have been studied extensively. Here, the Laplace equation with Dirichlet boundary condition on the free surface is solved using the boundary integral method, and a time integration method is used to find the particle displacements and velocity potential on the free surface. Finite element methods based on the MEL formulation have been developed in the 90s. Several researchers have pursued this approach, addressing the various challenges thrown open, such as velocity computation, pressure computation on moving surfaces, remeshing of the computational domain, smoothing and imposition of radiation condition. Apart from these, the implementation of the FE model in particular involves several computational issues such as element property computation, solution of large banded matrix equations, and efficient organization of computer storage, all of which are crucial for the computational tool to become successful. A study of these aspects constitutes the primary focus of the present work. The authors have recently developed a 3-D FE model employing the MEL formulation, which has been applied to predict waves in a flume and basin. The fluid domain is discretized using 20-node hexahedral elements. The free surface equations are solved in the time domain employing the three-point Adams-Bashforth method. Validation of the numerical model and relative computation times for salient steps in the FE model are discussed in the paper.

Probabilistic Finite Element Prediction of the Active Lower Limb Model

2012 ◽  
Vol 463-464 ◽  
pp. 1285-1290
Author(s):  
Arsene Corneliu
Keyword(s):  
Finite Element ◽  
Contact Pressure ◽  
Femoral Component ◽  
Lower Limb ◽  
Flexion Angle ◽  
Fe Model ◽  
Tibial Insert ◽  
Peak Contact Pressure ◽  
Input Variables ◽  
Femoral Flexion

The scope of this paper is to explore the input parameters of a Finite Element (FE) model of an active lower limb that are most influential in determining the size and the shape of the performance envelope of the kinematics and peak contact pressure of the knee tibial insert introduced during a Total Knee Replacement (TKR) surgery. The active lower limb FE model simulates the stair ascent and it provides a more complicated setup than the isolated TKR model which includes the femoral component and the tibial insert. It includes bones, TKR implant, soft tissues and applied forces. Two probabilistic methods are used together with the FE model to generate the performance envelopes and to explore the key parameters: the Monte Carlo Simulation Technique (MCST) and the Response Surface Method (RSM). It is investigated how the uncertainties in a reduced set of 22 input variables of the FE model affect the kinematics and peak contact pressure of the knee tibial insert. The kinematics is reported in the Grood and Suntay system, where all motion is relative to the femoral component of the TKR. Reported tibial component kinematics are tibio-femoral flexion angle, anterior-posterior and medial-lateral displacement, internal-external and varus-valgus rotation (i.e. abduction-adduction), while the reported patella kinematics are patella-femoral flexion angle, medial-lateral shift and medial-lateral tilt. Tibio-femoral and patella-femoral contact pressures are also of interest. Following a sensitivity analysis, a reduced set of input variables is derived, which represent the set of key parameters which influence the performance envelopes. The findings of this work are paramount to the orthopedic surgeons who may want to know the key parameters that can influence the performance of the TKR for a given human activity.

scholarly journals Finite element simulation of lower limb injuries to the driver in minibus frontal collisions

2016 ◽  
Vol 19 (3) ◽  
pp. 146-150 ◽  
Author(s):  
Liang-Liang Shi ◽  
Chen Lei ◽  
Kui Li ◽  
Shuo-Zhen Fu ◽  
Zheng-Wei Wu ◽  
...  
Keyword(s):  
Finite Element ◽  
Finite Element Simulation ◽  
Lower Limb ◽  
Lower Limb Injuries ◽  
Element Simulation ◽  
Limb Injuries ◽  
Frontal Collisions

Finite Element-Based Pelvic Injury Metric Creation and Validation in Lateral Impact for a Human Body Model

2018 ◽  
Vol 140 (6) ◽  
Author(s):  
Caitlin M. Weaver ◽  
Alexander M. Baker ◽  
Matthew L. Davis ◽  
Anna N. Miller ◽  
Joel D. Stitzel
Keyword(s):  
Finite Element ◽  
Human Body ◽  
Roc Curve ◽  
Injury Risk ◽  
Curve Analysis ◽  
Pelvic Injury ◽  
Fe Model ◽  
Lateral Impact ◽  
Roc Curve Analysis ◽  
Cross Sectional

Pelvic fractures are serious injuries resulting in high mortality and morbidity. The objective of this study is to develop and validate local pelvic anatomical, cross section-based injury risk metrics for a finite element (FE) model of the human body. Cross-sectional instrumentation was implemented in the pelvic region of the Global Human Body Models Consortium (GHBMC M50-O) 50th percentile detailed male FE model (v4.3). In total, 25 lateral impact FE simulations were performed using input data from cadaveric lateral impact tests performed by Bouquet et al. The experimental force-time data were scaled using five normalization techniques, which were evaluated using log rank, Wilcoxon rank sum, and correlation and analysis (CORA) testing. Survival analyses with Weibull distribution were performed on the experimental peak force (scaled and unscaled) and the simulation test data to generate injury risk curves (IRCs) for total pelvic injury. Additionally, IRCs were developed for regional injury using cross-sectional forces from the simulation results and injuries documented in the experimental autopsies. These regional IRCs were also evaluated using the receiver operator characteristic (ROC) curve analysis. Based on the results of all the evaluation methods, the equal stress equal velocity (ESEV) and ESEV using effective mass (ESEV-EM) scaling techniques performed best. The simulation IRC shows slight under prediction of injury in comparison to these scaled experimental data curves. However, this difference was determined not to be statistically significant. Additionally, the ROC curve analysis showed moderate predictive power for all regional IRCs.

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