FE Modeling of the Three-Layer Human Carotid Artery Under Impact Loadings

2007 ◽  
Author(s):  
Aihong Zhao ◽  
Ken Digges ◽  
Mark Field ◽  
David Richens
Keyword(s):  
Finite Element ◽  
Carotid Artery ◽  
Model Simulation ◽  
Material Model ◽  
Element Model ◽  
Traumatic Rupture ◽  
Aortic Tissue ◽  
Fe Model ◽  
Arbitrary Lagrangian Eulerian ◽  
The Impact

Blunt traumatic rupture of the carotid artery is a rare but life threatening injury. The histology of the artery is key to understanding the aetiology of this injury. The carotid artery is composed of three layers known as the tunica intima, media, and adventitia, with distinct biomechanical properties. In order to examine the behaviour of the carotid artery under external load we have developed a three layer finite element model of this vessel. A rubber-like material model from LS-DYNA was selected for the FE model. The Arbitrary-Lagrangian Eulerian (ALE) approach was adopted to simulate the interaction between the fluid (blood) and the structure (carotid). To verify the FE model, the impact bending tests are simulated using this FE model. Simulation results agree with tests results well. Furthermore, the mechanical behaviour of carotid artery tissues under impact loading were revealed by the simulations. The results provide a basis for a more in-depth investigation of the carotid artery in vehicle crashes. In addition, it provides a basis for further work on aortic tissue finite element modeling.

Finite Element Modeling of Aortic Tissue Using High Speed Experimental Data

2005 ◽  
Author(s):  
Muralikrishna Maddali ◽  
Chirag S. Shah ◽  
King H. Yang
Keyword(s):  
Experimental Data ◽  
Finite Element ◽  
High Speed ◽  
Material Model ◽  
Traumatic Rupture ◽  
Aortic Tissue ◽  
Model Parameters ◽  
Fe Model ◽  
Rubber Material ◽  
Material Constants

Traumatic rupture of the aorta (TRA) is responsible for 10% to 20% of motor vehicle fatalities [1]. Both finite element (FE) modeling and experimental investigations have enhanced our understanding of the injury mechanisms associated with TRA. Because accurate material properties are essential for the development of correct and authoritative FE model predictions, the objective of the current study was to identify a suitable material model and model parameters for aorta tissue that can be incorporated into FE aorta models for studying TRA. An Ogden rubber material (Type 77B in LS-DYNA 970) was used to simulate a series of high speed uniaxial experiments reported by Mohan [2] using a dumbbell shaped FE model representing human aortic tissue. Material constants were obtained by fitting model simulation results against experimentally obtained corridors. The sensitivity of the Ogden rubber material model was examined by altering constants G and alpha (α) and monitoring model behavior. One single set of material constants (α = 25.3, G = 0.02 GPa, and μ = 0.6000E-06 GPa) was found to fit uniaxial data at strain rates of approximately 100 s−1 for both younger and older aortic tissue specimens. Until a better material model is derived and other experimental data are obtained, it is recommended that the Ogden material model and associated constants derived from the current study be used to represent aorta tissue properties when using FE methods to investigate mechanisms of TRA.

scholarly journals 3D Finite Element Model Simulating the Behaviour of Filling Soils Used to Set Up a New Placement Method for Separate Sewer Systems

2019 ◽  
Vol 8 (3) ◽  
pp. 87-98
Author(s):  
Alaa Abbas ◽  
Felicite Ruddock ◽  
Rafid Alkhaddar ◽  
Glynn Rothwell ◽  
Iacopo Carnacina ◽  
...  
Keyword(s):  
Finite Element ◽  
Soil Properties ◽  
Model Simulation ◽  
New Method ◽  
Traffic Load ◽  
Scale Model ◽  
Fe Model ◽  
Fe Method ◽  
Buried Pipes ◽  
The Impact

The use of a finite element (FE) method and selection of the appropriate model to simulate soil elastoplastic behaviour has confirmed the importance and sensitivity of the soil properties on the accuracy when compared with experimental data. The properties of the filling soil play a significant role in determining levels of deformation and displacement of both the soil and subterranean structures when using the FE model simulation. This paper investigates the impact of the traffic load on the filling soil deformation when using the traditional method, one pipe in a trench, and a new method, two pipes in a single trench one over the other, for setting up a separate sewer system. The interaction between the buried pipes and the filling soils has been simulated using an elastoplastic FE model. A modified Drucker–Prager cap constitutive model was used to simulate the stress-strain behaviours of the soil. A series of laboratory tests were conducted to identify the elastoplastic properties of the composite soil used to bury the pipes. The FE models were calibrated using a physical lab model for testing the buried pipes under applied load. This allows the FE model to be confidently upgraded to a full-scale model. The pipe-soil interactions were found to be significantly influenced by the soil properties, the method of placing the pipes in the trench and the diameters of the buried pipes. The deformation of the surface soil was decreased by approximately 10% when using the new method of setting up the separate sewer.

scholarly journals A Simplified ALE model for finite element simulation of ballistic impacts with bullet splash – development and experimental validation

2021 ◽  
Vol 15 (57) ◽  
pp. 223-245
Author(s):  
Riccardo Andreotti ◽  
Sergio Abate ◽  
Andrea Casaroli ◽  
Mauro Quercia ◽  
Riccardo Fossati ◽  
...  
Keyword(s):  
Finite Element ◽  
Element Model ◽  
Forensic Sciences ◽  
Arbitrary Lagrangian Eulerian ◽  
Aisi 304L ◽  
Simplified Approach ◽  
Ballistic Impacts ◽  
Eulerian Formulation ◽  
Full Metal Jacket ◽  
The Impact

An original simplified finite element model is proposed to simulate the effects of non-penetrating ballistic impacts causing the so-called bullet splash phenomenon (complete bullet fragmentation), while no fragmentation is caused to the target. The model is based on the Arbitrary Lagrangian Eulerian formulation (ALE) and it simulates the impact as a fluid-structure interaction. The bullet splash phenomenon has been tested by experimental analyses of AISI 304L plates impacted by 9x21 FMJ (full metal jacket) bullets. The model has been developed with the aim of creating a simplified approach to be used in the industry and forensic sciences to simulate the non-penetrating interaction of soft impactors with hard targets. Comparisons between evidence and simulation results lead to the conclusion that the proposed approach can be used in a conservative way to estimate both local and global effects of bullet-splash phenomena.

FE Modeling of the Orthotropic and Three-Layered Human Thoracic Aorta

2006 ◽  
Author(s):  
Aihong Zhao ◽  
Ian Owens Pericevic ◽  
Kennerly Digges ◽  
Cing-Dao Kan ◽  
Moji Moatamedi ◽  
...  
Keyword(s):  
Finite Element ◽  
Impact Loading ◽  
Aortic Rupture ◽  
Material Model ◽  
Human Aorta ◽  
Single Element ◽  
Fe Model ◽  
Vehicle Crashes ◽  
Arbitrary Lagrangian Eulerian ◽  
Finite Element Software

The human aorta consists of three layers: intima, media and adventitia from the inner to outer layer. Since aortic rupture of victims in vehicle crashes frequently occurs in the intima and the media, latent aortic injuries are difficult to detect at the crash scene or in the emergency room. It is necessary to develop a multi-layer aorta finite element (FE) model to identify and describe the potential mechanisms of injury in various impact modes. In this paper, a novel three-layer FE aortic model was created to study aortic ruptures under impact loading. The orthotropic material model [1] has been implemented into a user-defined material subroutine in the commercial dynamic finite element software LS-DYNA version 970 [2], which was adopted in the aorta FE model. The Arbitrary-Lagrangian Eulerian (ALE) approach was adopted to simulate the interaction between the fluid (blood) and the structure (aorta). Single element verifications for the user-defined subroutine were performed. The mechanical behaviors of aortic tissues under impact loading were simulated by the aorta FE model. The models successfully predicted the rupture of the layers separately. The results provide a basis for a more in-depth investigation of blunt traumatic aortic rupture (BTAR) in vehicle crashes.

NONLINEAR FINITE ELEMENT ANALYSIS OF FRP STRENGTHENED RC BEAMS

2015 ◽  
Vol 2 (1) ◽  
Author(s):  
Prabin Pathak ◽  
Y. X. Zhang
Keyword(s):  
Finite Element ◽  
Plastic Material ◽  
Experimental Studies ◽  
Material Model ◽  
Element Model ◽  
Steel Reinforcement ◽  
Elastic Model ◽  
Fe Model ◽  
Rc Beams ◽  
Element Analysis

A simple, accurate and efficient finite element model is developed in ANSYS for numerical modelling of the nonlinear structural behavior of FRP strengthened RC beams under static loading in this paper. Geometric nonlinearity and material non-linear properties of concrete and steel rebar are accounted for this model. Concrete and steel reinforcement are modelled using Solid 65 element and Link 180 element, and FRP and adhesive are modelled using Shell 181element and Solid 45 element. Concrete is modelled using Nitereka and Neal’s model for compression, and isotropic and linear elastic model before cracking with strength gradually reducing to zero after cracking for tension. For steel reinforcement, the elastic perfectly plastic material model is used. FRPs are assumed to be linearly elastic until rupture and epoxy is assumed to be linearly elastic. The new FE model is validated by comparing the computed results with those obtained from experimental studies.

A 3-Dimensional Eulerian Finite Element Model for Ice Scour

2004 ◽  
Author(s):  
Ibrahim Konuk ◽  
Robert Gracie
Keyword(s):  
Finite Element ◽  
Transport Process ◽  
Soil Mechanics ◽  
Element Model ◽  
Fe Model ◽  
Soil Deformation ◽  
Arbitrary Lagrangian Eulerian ◽  
Soil Material ◽  
Soil Transport ◽  
Current Design

The main objective of this paper is to present a Finite Element (FE) numerical model of the ice scour process. The FE model is developed to study the soil deformation and transport process around the scouring ice and to investigate the effects of the ice scour on a pipeline buried or laid in a trench cut on the seabed. The focus of this paper is on the scours caused by ice ridges commonly observed in the Beaufort Sea. The developed FE model is a new application of the Arbitrary-Lagrangian-Eulerian (ALE) method to a soil mechanics problem involving very large deformations. Soil material, originally positioned in front of the ice ridge, is transported forward and sideways through the FE mesh and deposited in the berms formed on both sides of the scour. The soil material below the scour depth similarly moves across the mesh simulating the subscour effect. An inviscid CAP plasticity constitutive model is used to model the soil material. This paper focuses on the interaction between the ice ridge and the seabed. It describes soil transport process involved during the interaction. The soil deformation field obtained from the model is compared with the empirical deformation functions commonly used in current design methods. Future papers will report on the interaction between the ice ridge, the infill in the pipeline trench, and the pipeline; the influence of the soil properties of the trench and the seabed will also be studied.

Advanced finite-element modelling of a 32-panel soccer ball

2007 ◽  
Vol 221 (11) ◽  
pp. 1309-1319 ◽  
Author(s):  
D S Price ◽  
R Jones ◽  
A R Harland
Keyword(s):  
Finite Element ◽  
Polyester Fibre ◽  
Material Model ◽  
Element Model ◽  
Impact Testing ◽  
Material Anisotropy ◽  
Soccer Ball ◽  
Impact Characteristics ◽  
The Impact ◽  
Kinetic Energy Loss

The current paper details the development of a finite-element model of a manually stitched, textile reinforced 32-panel soccer ball used in elite competition. The model included material anisotropy, a stiffer region representative of the polyester fibre based stitching, and a latex bladder membrane which was pressurized through inflation. A stiffness proportional damping coefficient was included within the material model to describe kinetic energy loss characteristics. The model was validated through experimental impact testing at speeds representative of play. It was found that the combined effects of material anisotropy, panel stitching, and panel configuration had a profound effect on the impact characteristics of the ball.

Modeling and Estimation of Rheological Properties Based on Finite Element Analysis and Computer Simulation Technology

2013 ◽  
Vol 427-429 ◽  
pp. 293-297
Author(s):  
Qi Jun Zhang
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
Rheological Properties ◽  
Model Simulation ◽  
Raw Materials ◽  
Estimation Method ◽  
Element Model ◽  
Fe Model ◽  
Element Analysis ◽  
Physical Model Simulation

By the relevant engineering and manufacturing of food rheological properties to estimate, and developing unified object based on 2D/3D dynamic finite element model, to carry out physical model simulation of five elements, then to further extended to deal with heterogeneous hierarchical objects. There are three kinds of food raw materials that are tested, its deformation and mechanical behavior are also assessed, and then according to the optimization FE, it is proposed to estimate the object's rheological properties. The results show that the FE model and the estimation method can accurately reproduce food rheological and deformation, and in the manufacturing process, the finite element model can be used to predict the rheological behavior of food products.

The Impact of an Open-Book Pelvic Ring Injury on Bone Strain: Validation of a Finite Element Model and Analysis Within the Gait Cycle

2021 ◽  
Vol 143 (7) ◽  
Author(s):  
Zoryana Salo ◽  
Hans Kreder ◽  
Cari Marisa Whyne
Keyword(s):  
Finite Element ◽  
Gait Cycle ◽  
Pelvic Ring ◽  
Element Model ◽  
Heel Strike ◽  
Fe Model ◽  
Open Book ◽  
Pubic Ramus ◽  
Biomechanical Behavior ◽  
The Impact

Abstract The threshold for surgical stabilization for an open-book pelvic fracture is not well defined. The purpose of this research was to validate the biomechanical behavior of a specimen-specific pelvic finite element (FE) model with an open-book fracture with the biomechanical behavior of a cadaveric pelvis in double leg stance configuration under physiologic loading, and to utilize the validated model to compare open book versus intact strain patterns during gait. A cadaveric pelvis was experimentally tested under compressive loading in double leg stance, intact, and with a simulated open-book fracture. An intact FE model of this specimen was reanalyzed with an equivalent simulated open-book fracture. Comparison of the FE generated and experimentally measured strains yielded an R2 value of 0.92 for the open-book fracture configuration. Strain patterns in the intact and fractured models were compared throughout the gait cycle. In double leg stance and heel-strike/heel-off models, tensile strains decreased, especially in the pubic ramus contralateral to the injury, and compressive strains increased in the sacroiliac region of the injured side. In the midstance/midswing gait configuration, higher tensile and compressive FE strains were observed on the midstance side of the fractured versus intact model and decreased along the superior and inferior pubic rami and ischium, with midswing side strains reduced almost to zero in the fractured model. Identified in silico patterns align with clinical understanding of open-book fracture pathology suggesting future potential of FE models to quantify instability and optimize fixation strategies.

Finite Element Modeling of Coupled Flexible Multibody Dynamics and Liquid Sloshing

2006 ◽  
Author(s):  
Tamer M. Wasfy
Keyword(s):  
Finite Element ◽  
Flexible Multibody Dynamics ◽  
Element Model ◽  
Rigid Bodies ◽  
Liquid Sloshing ◽  
Fe Model ◽  
Arbitrary Lagrangian Eulerian ◽  
Interface Elements ◽  
Test Fixture ◽  
Flexible Multibody

A time-accurate finite element model for simulating the fully-coupled dynamic response of flexible multibody systems and liquid sloshing in tanks is presented. The semi-discrete combined solid and fluid equations of motions are integrated using a time-accurate parallel explicit solver. The FE model consists of: hexahedral, beam, and truss solid elements; rigid bodies; joints; actuators; hexahedral incompressible fluid elements; and quadrilateral fluid-solid interface elements. The fluid mesh is modeled using a very light and compliant solid mesh which allows the fluid mesh to move/deform along with the tank using the Arbitrary Lagrangian-Eulerian formulation. The fluid’s free-surface is modeled using an acceptor-donor volume-of-fluid based algorithm. The motion of the solid and fluid is referred to a global inertial Cartesian reference frame. A total Lagrangian deformation description is used for the solid elements. The penalty technique is used to model the joints. Numerical simulations are presented for a half-filled tank supported by linear springs mounted on a test fixture.

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