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.

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.

scholarly journals Numerical simulation of blanking process

2018 ◽  
Vol 157 ◽  
pp. 02038
Author(s):  
Peter Pecháč ◽  
Milan Sága
Keyword(s):  
Numerical Simulation ◽  
Finite Element ◽  
Steel Sheet ◽  
Plastic Material ◽  
Material Model ◽  
Rolled Steel ◽  
Finite Element Software ◽  
History Of ◽  
Cold Rolled ◽  
Blanking Process

This paper presents numerical simulation of blanking process for cold-rolled steel sheet metal. The problem was modeled using axial symmetry in commercial finite element software ADINA. Data obtained by experimental measurement were used to create multi-linear plastic material model for simulation. History of blanking force vs. tool displacement was obtained.

scholarly journals Low Cost Frictional Seismic Base-Isolation of Residential New Masonry Buildings in Developing Countries: A Small Masonry House Case Study

2017 ◽  
Vol 11 (1) ◽  
pp. 1026-1035 ◽  
Author(s):  
Ahmad Basshofi Habieb ◽  
Gabriele Milani ◽  
Tavio Tavio ◽  
Federico Milani
Keyword(s):  
Finite Element ◽  
Seismic Vulnerability ◽  
Base Isolation ◽  
Low Cost ◽  
Element Model ◽  
Shaking Table ◽  
Fe Model ◽  
Isolation System ◽  
Finite Element Software ◽  
Non Linear

Introduction:An advanced Finite Element model is presented to examine the performance of a low-cost friction based-isolation system in reducing the seismic vulnerability of low-class rural housings. This study, which is mainly numerical, adopts as benchmark an experimental investigation on a single story masonry system eventually isolated at the base and tested on a shaking table in India.Methods:Four friction isolation interfaces, namely, marble-marble, marble-high-density polyethylene, marble-rubber sheet, and marble-geosynthetic were involved. Those interfaces differ for the friction coefficient, which was experimentally obtained through the aforementioned research. The FE model adopted here is based on a macroscopic approach for masonry, which is assumed as an isotropic material exhibiting damage and softening. The Concrete damage plasticity (CDP) model, that is available in standard package of ABAQUS finite element software, is used to determine the non-linear behavior of the house under non-linear dynamic excitation.Results and Conclusion:The results of FE analyses show that the utilization of friction isolation systems could much decrease the acceleration response at roof level, with a very good agreement with the experimental data. It is also found that systems with marble-marble and marble-geosynthetic interfaces reduce the roof acceleration up to 50% comparing to the system without isolation. Another interesting result is that there was little damage appearing in systems with frictional isolation during numerical simulations. Meanwhile, a severe state of damage was clearly visible for the system without isolation.

scholarly journals A Phenomenological Mechanical Material Model for Precipitation Hardening Aluminium Alloys

Metals ◽  
2019 ◽  
Vol 9 (11) ◽  
pp. 1165 ◽  
Author(s):  
Hannes Fröck ◽  
Lukas Vincent Kappis ◽  
Michael Reich ◽  
Olaf Kessler
Keyword(s):  
Mechanical Properties ◽  
Heat Treatment ◽  
Finite Element ◽  
Phase Transformation ◽  
Aluminium Alloys ◽  
Material Model ◽  
Heat Treatments ◽  
Maximum Temperature ◽  
Finite Element Software ◽  
Welding Processes

Age hardening aluminium alloys obtain their strength by forming precipitates. This precipitation-hardened state is often the initial condition for short-term heat treatments, like welding processes or local laser heat treatment to produce tailored heat-treated profiles (THTP). During these heat treatments, the strength-increasing precipitates are dissolved depending on the maximum temperature and the material is softened in these areas. Depending on the temperature path, the mechanical properties differ between heating and cooling at the same temperature. To model this behavior, a phenomenological material model was developed based on the dissolution characteristics and experimental flow curves were developed depending on the current temperature and the maximum temperature. The dissolution characteristics were analyzed by calorimetry. The mechanical properties at different temperatures and peak temperatures were recorded by thermomechanical analysis. The usual phase transformation equations in the Finite Element Method (FEM) code, which were developed for phase transformation in steels, were used to develop a phenomenological model for the mechanical properties as a function of the relevant heat treatment parameters. This material model was implemented for aluminium alloy 6060 T4 in the finite element software LS-DYNA (Livermore Software Technology Corporation).

Research on Influence of Flexible Parts’ Rigidity to Passenger Car Exhaust System’s Modal

2011 ◽  
Vol 117-119 ◽  
pp. 141-145
Author(s):  
Shou Li Yuan ◽  
Wen Chang Zhang ◽  
Zhi En Liu ◽  
Chao Wang ◽  
Ding Yuan Fu
Keyword(s):  
Finite Element ◽  
Natural Frequencies ◽  
Exhaust System ◽  
Fe Model ◽  
Passenger Cars ◽  
Passenger Car ◽  
Finite Element Software ◽  
Modeling Methods ◽  
Car Exhaust ◽  
Flexible Parts

The finite element modeling methods of a passenger car exhaust system’s flexible parts are introduced. A finite element (FE) model of the exhaust system is established with the finite element software and modal analysis of the FE Model is carried out. Through changing both automotive exhaust hangers’ Z direction of stiffness and bellows’ each direction of stiffness, the data of natural frequencies and vibrating modes of the exhaust system were obtained respectively. Comparing and analyzing the results indicates how the stiffness of exhaust hangers and bellows influences the modal of passenger cars’ exhaust system.

An Alternate Approach to SHPB Tests to Compute Johnson-Cook Material Model Constants for 97 WHA at High Strain Rates and Elevated Temperatures Using Machining Tests

2020 ◽  
Vol 143 (2) ◽  
Author(s):  
Chithajalu Kiran Sagar ◽  
Amrita Priyadarshini ◽  
Amit Kumar Gupta ◽  
Tarun Kumar ◽  
Shreya Saxena
Keyword(s):  
Finite Element ◽  
High Strain Rate ◽  
Strain Rate ◽  
Elevated Temperatures ◽  
High Strain ◽  
Optimization Technique ◽  
Material Model ◽  
Computational Techniques ◽  
Fe Model

Abstract With advances in computational techniques, numerical methods such as finite element method (FEM) are gaining much of the popularity for analysis as these substitute the expensive trial and error experimental techniques to a great extent. Consequently, selection of suitable material models and determination of precise material model constants are one of the prime concerns in FEM. This paper presents a methodology to determine the Johnson-Cook constitutive equation constants (JC constants) of 97 W Tungsten heavy alloys (WHAs) under high strain rate conditions using machining tests in conjunction with Oxley’s predictive model and particle swarm optimization (PSO) algorithm. Currently, availability of the high strain rate data for 97 WHA are limited and consequently, JC constants for the same are not readily available. The overall methodology includes determination of three sets of JC constants, namely, M1 and M2 from the Split-Hopkinson pressure bar (SHPB) test data available in literature by using conventional optimization technique and artificial bee colony (ABC) algorithm, respectively. However, M3 is determined from machining tests using inverse identification method. To validate the identified JC constants, machining outputs (cutting forces, temperature, and shear strain) are predicted using finite element (FE) model by considering M1, M2, and M3 as input under different cutting conditions and then validated with corresponding experimental values. The predicted outputs obtained using JC constants M3 closely matched with that of the experimental ones with error percentage well within 10%.

scholarly journals Hot Workability of Ultra-Supercritical Rotor Steel Using a 3-D Processing Map Based on the Dynamic Material Model

Materials ◽  
2020 ◽  
Vol 13 (18) ◽  
pp. 4118
Author(s):  
Xuewen Chen ◽  
Yuqing Du ◽  
Tingting Lian ◽  
Kexue Du ◽  
Tao Huang
Keyword(s):  
Finite Element ◽  
Alloy Steel ◽  
Thermal Processing ◽  
Processing Map ◽  
Three Dimensional ◽  
Material Model ◽  
Strain Rates ◽  
Rotor Steel ◽  
Dynamic Material Model ◽  
Finite Element Software

As a new-type of ultra-supercritical HI-IP rotor steel, X12CrMoWVNbN10-1-1 alloy steel has excellent integrative performance, which can effectively improve the power generation efficiency of the generator set. In this paper, uniaxial thermal compression tests were carried out over a temperature range of 950–1200 °C and strain rates of 0.05–5 s−1 with a Gleeble-1500D thermal simulation testing machine. Moreover, based on hot compression experimental data and the theory of processing diagrams, in combination with the dynamic material model, a three-dimensional (3-D) thermal processing map considering the effect of strain was constructed. It was concluded that optimum thermal deformation conditions were as follows: the temperature range of 1150–1200 °C, the strain rate range of 0.05–0.634 s−1. Through secondary development of the finite element (FE) software FORGE®, three-dimensional thermal processing map data were integrated into finite element software FORGE®. The distributions of instability coefficient and power dissipation coefficient were obtained over various strain rates and temperatures of the Ø 8 × 12 mm cylinder specimen by using finite element simulation. It is shown that simulation results are consistent with the microstructure photos. The method proposed in this paper, which integrates the three-dimensional processing map into the finite element software FORGE® (Forge NxT 2.1, Transvalor, Nice, France), can effectively predict the formability of X12CrMoWVNbN10-1-1 alloy steel.

Numerical Simulation of the Airliner Door under Explosion Impact Loading and Reinforcement Technique

2011 ◽  
Vol 704-705 ◽  
pp. 450-454
Author(s):  
Ying Liu ◽  
Dun Wen Zuo ◽  
Yao Hua Wang ◽  
Xin Hua Chen ◽  
Ji Xian He ◽  
...  
Keyword(s):  
Numerical Simulation ◽  
Finite Element ◽  
Impact Loading ◽  
Physical Parameters ◽  
Simplified Models ◽  
Finite Element Software ◽  
Combination Of Methods ◽  
Set Up ◽  
Reinforcement Measures ◽  
Passenger Cabin

This paper comprehensively uses a combination of methods of theoretical analysis, numerical simulation as well as the model test to do the structural analysis to some type of the passenger cabin doors, so as to set up the model for the descriptions of the part subjected to explosion impact loading; Through the tests, we gets the explosion impact loading and other important physical parameters. Aimed at the material of the door as well as the simplified models subjected to the explosion impact loading, the numerical simulation is put up by the finite element software ABAQUS. The necessity of the reinforcement is deeply analyzed as well as the difficulties during the process of the reinforcement, furthermore, the reinforcement measures are proposed to the airliner door. Keywords: Numerical simulation; Explosion impact loading; Explosion-combustion power equipments

Mechanical Analysis of the Recycled Concrete Brick Masonry Wall under In-Plane Load

2011 ◽  
Vol 250-253 ◽  
pp. 278-282 ◽  
Author(s):  
Song Gu ◽  
Guo Ping Chen ◽  
Shui Wen Zhu
Keyword(s):  
Finite Element ◽  
Mechanical Analysis ◽  
Masonry Wall ◽  
Brick Masonry ◽  
Recycled Concrete ◽  
Masonry Walls ◽  
Fe Model ◽  
Element Analysis ◽  
Finite Element Software ◽  
Strength Capacity

The purpose of this paper was to investigate the mechanical behavior and failure mode of recycled concrete brick masonry wall under cycling in-plane load. These models of masonry walls were constructed in the laboratory and experimented under in-plane cycling load. The masonry wall was made of recycled concrete bricks joined by mortar, with gypsum lining on both faces. A simulation based on the experiment was carried out using the finite element software ANSYS. In the proposed FE model, the recycling concrete bricks and joints were modeled separately, allowing for nonlinear deformation characteristics of the two materials. The results of the experiment and the finite element analysis were analyzed and compared. When the stress distributions were taken into consideration in the experiments and solutions of ANSYS, it was observed that the stress concentration occurred on two diagonals of the masonry wall. The destruction process and characteristics of the masonry wall were obtained by the experiments. The results of finite element method matched experimental results very well. The FE software ANSYS can be used in the analysis of recycling concrete brick masonry walls under in-plane cycling load and strength capacity.

scholarly journals Collapse Behaviour of a Concrete-Filled Steel Tubular Column Steel Beam Frame under Impact Loading

2021 ◽  
Vol 2021 ◽  
pp. 1-15
Author(s):  
Lian Song ◽  
Hao Hu ◽  
Jian He ◽  
Xu Chen ◽  
Xi Tu
Keyword(s):  
Finite Element ◽  
Impact Loading ◽  
Mechanical Performance ◽  
Impact Load ◽  
Frame Structure ◽  
Actual Condition ◽  
Transverse Impact ◽  
Time Curve ◽  
Finite Element Software ◽  
The Impact

The progressive collapse of a concrete-filled steel tubular (CFST) frame structure is studied subjected to impact loading of vehicle by the finite-element software ABAQUS, in the direct simulation method (DS) and alternate path method (AP), respectively. Firstly, a total of 14 reference specimens including 8 hollow steel tubes and 6 CFST specimens were numerically simulated under transverse impact loading for verification of finite-element models, which were compared with the existing test results, confirming the overall similarity between them. Secondly, a finite-element analysis (FEA) model is established to predict the impact behaviour of a five-storey and three-span composite frame which was composed of CFST columns and steel beams under impact vehicle loading. The failure mode, internal force-time curve, displacement-time curve, and mechanical performance of the CFST frame were obtained through analyzing. Finally, it is concluded that the result by the DS method is closer to the actual condition and the collapse process of the structure under impact load can be relatively accurately described; however, the AP method is not.

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