ADINA Publications

Page 25

The Theory used in ADINA is richly documented in the following books by K.J. Bathe and co-authors


Finite Element Procedures
 

Finite Element Procedures in Engineering Analysis

Numerical Methods in Finite Element Analysis
 


The Mechanics of Solids and Structures — Hierarchical ...


The Finite Element Analysis of Shells — Fundamentals


Inelastic Analysis of Solids and Structures

 
 
To Enrich Life
(Sample pages here)
 

 

Following are more than 700 publications — that we know of — with reference to the use of ADINA. The pages give the Abstracts of some papers published since 1986 referring to ADINA. The most recent papers are listed first. All these papers may be searched using the box:

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Analysis of distortion of slope excavation based on ADINA

Zhang, Xiang-Dong (College of Civil and Architecture Engineering, Liaoning Technical University); Zhang, Shu-Kun; Yang, Kui-Qing Source: Yantu Lixue/Rock and Soil Mechanics, v 27, n SUPPL., October, 2006, p 1153-1155 Language: Chinese

ISSN: 1000-7598

Publisher: Academia Sinica

Abstract: The numerical simulation of slope cutting deformation is carried out with ADINA; and a 2D finite element analysis model is established. And then the influences of two kinds of construction schemes on slope deformations are compared; and the variation regularity of the horizontal shift of bolt is analyzed too. The results show that the side slope unloading distortion and excavation rebound relate to the selection of construction scheme very much. (10 refs.)

Keywords:  Slope stability  -  Computer simulation  -  Deformation  -  Excavation  -  Finite element method  -  Unloading

Secondary  Keywords:  Side slope  -  ADINA software  -  Distortion

 

Hydroplaning And Skid Resistance Analysis Using Numerical Modeling

G.P.R. Ong

Department Of Civil And Environmental Engineering National University Of Singapore

Ph.D. Thesis, 2006

Abstract: The objectives of this research are (a) to develop a numerical model for simulating hydroplaning of a locked-wheel sliding over a smooth plane pavement using an assumed tire deformation profile, (b) to apply the proposed numerical model with the assumed tire deformation profile to study the effect of pavement grooving on hydroplaning, (c) to propose a design procedure for pavement groove dimensions in hydroplaning control, and (d) to propose an improved numerical model considering coupled tire-fluid-pavement interaction for estimating skid resistance and hydroplaning speed of a locked-wheel sliding over a smooth plane pavement. The research in this study have adopted a two-stage approach, the first involves developing numerical models to simulate hydroplaning using an assumed tire deformation profile on plane pavement surfaces or pavement with longitudinal and transverse pavement groovings, and the second involves developing improved models to simulate hydroplaning and wet pavement skid resistance with the consideration of tire-fluid-pavement interaction.

 

Application of finite element method in dental implant research

R.C. Van Staden, H. Guan, Y.C. Loo

School of Engineering, Griffith University Gold Coast Campus, Australia
Comput Methods Biomech Biomed Engin., 9(4):257-70, 2006

Abstract: This article provides a review of the achievements and advancements in dental technology brought about by computer-aided design and the all powerful finite element method of analysis. The scope of the review covers dental implants, jawbone surrounding the implant and the biomechanical implant and jawbone interaction. Prevailing assumptions made in the published finite element analysis, and their limitations are discussed in some detail which helps identify the gaps in research as well as future research direction.

Keywords: Dental implant - Implant-jawbone interaction - Design - Finite element analysis

 

3D geometric reconstruction of thoracic aortic aneurysms

A. Borghi1, N.B Wood1, R.H Mohiaddin2 and X.Y. Xu1

1 Department of Chemical Engineering, South Kensington Campus, Imperial College London, UK
2 Royal Brompton and Harefield NHS Trust, Sydney Street, London, UK

BioMedical Engineering OnLine, 5:59, 2006

Abstract: The thoracic aortic aneurysm (TAA) is a pathology that involves an expansion of the aortic diameter in the thoracic aorta, leading to risk of rupture. Recent studies have suggested that internal wall stress, which is affected by TAA geometry and the presence or absence of thrombus, is a more reliable predictor of rupture than the maximum diameter, the current clinical criterion. Accurate reconstruction of TAA geometry is a crucial step in patient-specific stress calculations. Methods: In this work, a novel methodology was developed, which combines data from several sets of magnetic resonance (MR) images with different levels of detail and different resolutions. Two sets of images were employed to create the final model, which has the highest level of detail for each component of the aneurysm (lumen, thrombus, and wall). A reference model was built by using a single set of images for comparison. This approach was applied to two patient-specific TAAs in the descending thoracic aorta. Results: The results of finite element simulations showed differences in stress pattern between the coarse and fine models: higher stress values were found with the coarse model and the differences in predicted maximum wall stress were 30% for patient A and 11% for patient B. Conclusion: This paper presents a new approach to the reconstruction of an aneurysm model based on the use of several sets of MR images. This enables more accurate representation of not only the lumen but also the wall surface of a TAA taking account of intraluminal thrombus.

Keywords: Computational geometry — Computer simulation — Finite element method — Image reconstruction — Magnetic resonance imaging — Mathematical models — Medical imaging — Pathology

 

 

 

Use of Fiber-Reinforced Polymer Composite Elements to Enhance Structural Steel Member Ductility

N.B. Accord and C.J. Earls

Dept. of Civil and Environmental Engineering, Univ. of Pittsburgh, Pittsburgh, PA 15261.

Journal of Composites for Construction, 10(4):337-344, 2006

Abstract: An innovative use of fiber-reinforced polymer composite materials to control the manifestation of local buckling in a steel section during plastic hinging is discussed in the present work. This discussion focuses on a technique wherein the constituent plate components in a steel I-shaped cross section are braced against local plate buckling modes through the imposition of thin longitudinal strips whose function is to enforce a nodal line along a plate element. This work demonstrates that such an approach increases the critical load for individual steel plate elements and helps to constrain plastic flow for these same elements so that the structural ductility of the overall cross section is enhanced. The research work discussed herein is analytical in nature. Detailed nonlinear finite element models are created using traditional techniques implemented on the commercially available software system ADINA. Specifics pertaining to bondline response are not treated.

Keywords: Fiber reinforced polymers — Composite materials —  Steel structures — Ductility — Buckling — Computer software

 


A simple finite element formulation for large deflection analysis of nonprismatic slender beams

Al-Sadder, Samir Z. (Department of Civil Engineering, Faculty of Engineering, Hashemite University); Othman, Ra'ad A.; Shatnawi, Anis S. Source: Structural Engineering and Mechanics, v 24, n 6, Dec 20, 2006, p 647-664

ISSN: 1225-4568 CODEN: SEGMEQ

Publisher: Techno Press

Abstract: In this study, an improved finite element formulation with a scheme of solution for the large deflection analysis of inextensible prismatic and nonprismatic slender beams is developed. For this purpose, a three-noded Lagrangian beam-element with two dependent degrees of freedom per node (i.e., the vertical displacement, y, and the actual slope, dylds = sineθ, where s is the curved coordinate along the deflected beam) is used to derive the element stiffness matrix. The element stiffness matrix in the global xy-coordinate system is achieved by means of coordinate transformation of a highly nonlinear (6 x 6) element matrix in the local sy-coordinate. Because of bending with large curvature, highly nonlinear expressions are developed within the global stiffness matrix. To achieve the solution after specifying the proper loading and boundary conditions, an iterative quasi-linearization technique with successive corrections are employed considering these nonlinear expressions to remain constant during all iterations of the solution. In order to verify the validity and the accuracy of this study, the vertical and the horizontal displacements of prismatic and nonprismatic beams subjected to various cases of loading and boundary conditions are evaluated and compared with analytic solutions and numerical results by available references and the results by ADINA, and excellent agreements were achieved. The main advantage of the present technique is that the solution is directly obtained, i.e., non-incremental approach, using few iterations (3 to 6 iterations) and without the need to split the stiffness matrix into elastic and geometric matrices. (44 refs.)

Keywords:  Beams and girders  -  Boundary conditions  -  Deflection (structures)  -  Finite element method  -  Iterative methods  -  Linearization  -  Loads (forces)  -  Stiffness

Secondary  Keywords:  Nonprismatic slender beams  -  Lagrangian beam-element  -  Coordinate transformation  -  Curvature  -  Nonprismatic beams

 


Moisture-temperature coupling mathematical model in freezing soil and finite element numerical simulation

Wang, Ren-He (Research Center of Mining Underground Engineering, Anhui University of Science and Technology); Li, Dong-Wei Source: Meitan Xuebao/Journal of the China Coal Society, v 31, n 6, December, 2006, p 757-760 Language: Chinese

ISSN: 0253-9993 CODEN: MTHPDA

Publisher: China Coal Society

Abstract: The artificial multi-coil pipes frozen model experiment results show that the temperature gradient is the main reason of causing moisture migration. Therefore the moisture-temperature coupling control equation was proposed in the frozen soil. The numerical simulation on moisture-temperature coupling was realized in ADINA finite element program. Temperature and moisture change rule of the measuring points in freeze model experiment is consistent with the numerical simulation results, it shows that using this method can carry on the moisture-temperature coupling analysis in the formation process for artificial multi-coil pipes frozen wall. (9 refs.)


Model tests on cone-shaped piles in frozen soils and finite element analysis

Li, Dong-Wei (Department of Civil Engineering, Anhui University of Science and Technology); Wang, Ren-He; Hu, Pu; Lin, Bin Source: Yantu Gongcheng Xuebao/Chinese Journal of Geotechnical Engineering, v 28, n SUPPL., November, 2006, p 1529-1533 Language: Chinese

ISSN: 1000-4548 CODEN: YGXUEB

Publisher: Chinese Society of Civil Engineering

Abstract: The capacity characteristics could be obtained by model tests on cone-shaped piles in frozen soils. The 'step' phenomena and drop-down segments of Q-S curves were not found, and the destroy mode of frozen soils was close to the progressive one. Through analyzing rheology model of frozen soils, the theory that the nonlinear Newtonian element replaces the linear one was proposed, and the improved Xiyuan model was established, which was embedded in ADINA FEM. Using the improved Xiyuan model, the model tests on cone-shaped piles in frozen soils were carried on finite element numerical simulation. The results of model experiments are close to the calculated ones, and it shows that the method of finite element numerical simulation can provide some references to the design of cone-shaped piles in frozen soils. (10 refs.)


Spreading mechanism in the coating process of a space solar cell

Zhao, Hui (School of Mechanical Eng., Shanghai Jiaotong Univ.); Fu, Zhuang; Wu, Yue-Xin; Yan, Wei-Xin; Liu, Ren-Qiang; Zhao, Yan-Zheng Source: Shanghai Jiaotong Daxue Xuebao/Journal of Shanghai Jiaotong University, v 40, n 10, October, 2006, p 1786-1789 Language: Chinese

ISSN: 1006-2467 CODEN: SCTPDH

Publisher: Shanghai Jiao Tong University

Abstract: The bonding operation of a space solar cell consists of three processes: adhesive coating from a syringe, adhesive's planar spreading and bonding of an anti-irradiation cover-glass to a space solar cell. The adhesive's planar spreading on the space solar cell was analyzed. Based on non-Newtonian fluid theory, the adhesive's planar spreading model was founded, the finite element software Adina was employed to trace the moving interface based on the method of Volume of Fluid (VOF), and experiments were performed to validate the simulative results. Thus the area and depth of the adhesive layer before bonding were obtained, and used as initial parameters in next bonding process. Meanwhile, a new solution for planar spreading was presented. (9 refs.)

Keywords:  Solar cells  -  Encapsulation  -  Spacecraft  -  Industrial robots  -  Finite element method  -  Computer simulation

Secondary  Keywords:  Space solar cell  -  Spreading  -  Non-Newtonian fluid  -  Moving boundary  -  Fluid volume method

 


FSI FEA simulation of liquid-supplement valves in gas-pressurized hydraulic dampers

Lu, Zhen-Hua (Department of Automotive Engineering, Tsinghua University); Jiang, Li-Quan Source: Gongcheng Lixue/Engineering Mechanics, v 23, n 11, November, 2006, p 163-169 Language: Chinese

ISSN: 1000-4750 CODEN: GOLIEB

Publisher: Tsinghua University

Abstract: Two typical liquid-supplement valves in double-tube gas-pressurized hydraulic dampers of car suspension are compared with each other by experiments and finite element simulations. Three-dimensional Fluid-Structure Interaction models of the two liquid-supplement valves are set up with the Finite Element Analysis code ADINA. The working characteristics, transient fluid pressure and velocity distribution of each valve, as well as the kinematical response of the valve disc, are simulated using the ADINA FSI module. The difference between the orifice structures of this two liquid-supplement valves leads to obvious difference in liquid-supplement capacity between them, which shows that the critical velocity of the performance degradation of a liquid valve can be increased by improving the design of orifice structure. (11 refs.)

Keywords:  Valves (mechanical)  -  Automobile suspensions  -  Fluid dynamics  -  Fluid structure interaction  -  Orifices  -  Damping  -  Finite element method  -  Computer simulation  -  Mathematical models

Secondary Keywords:  Double-tube gas-pressurized hydraulic damper  -  Nonlinear dynamic characteristics  -  Liquid-supplement valve

 

Improved Nishihara model and realization in ADINA FEM

Wang, Ren-He (Department of Civil Engineering, Anhui University of Science and Technology); Li, Dong-Wei; Wang, Xiu-Xi Source: Yantu Lixue/Rock and Soil Mechanics, v 27, n 11, November, 2006, p 1954-1958 Language: Chinese

ISSN: 1000-7598

Publisher: Academia Sinica

Abstract: Through analyzing the present rheological models and experimenting lots of creeping tests of frozen clay specimens under uniaxial stress states, the results show that the nonlinear N element substitute for the linear one is feasible and the Xiyuan model is improved. Making use of the Mises yield criterion, a soft matrix is derived to use numerical calculating as a viscous-elastic-plastic material. Numerical simulation of the shaft well excavation process and field measurements of the deformation of deep soil frozen wall in Huainan Mine show that the improved Nishihara model is feasible for FEM numerical simulation of deep soil frozen wall. (16 refs.)

Keywords:  Frozen soils  -  Clay  -  Creep  -  Deformation  -  Excavation  -  Finite element method  -  Mathematical models  -  Computer simulation

Secondary  Keywords:  Improved Nishihara model  -  Frozen wall  -  ADINA FEM  -  Frozen clay

 


Nonlinear elastoplastic behaviour of intermittently welded stiffened plates under inplane compression

Khedmati, Mohammad Reza (Department of Marine Structural Eng., Amirkabir University of Technology, Faculty of Marine Technology); Rastani, Mehran Source: Proceedings of the International Conference on Offshore Mechanics and Arctic Engineering - OMAE, v 2006, Proceedings of 25TH International Conference on Offshore Mechanics and Arctic Engineering, OMAE 2006, 2006, 12p

CODEN: PIOSEB

Conference: 25TH International Conference on Offshore Mechanics and Arctic Engineering, OMAE 2006, Jun 4-9 2006, Hamburg, Germany Sponsor: Ocean, Offshore, and Arctic Engineering Division of ASME

Publisher: American Society of Mechanical Engineers

Abstract: The objective of this study is to investigate the sensitivity of the ultimate strength and failure mechanism of stiffened plates constructed by different welding methods in common. A series of detailed numerical analyses of longitudinally stiffened steel plates subjected to inplane compressive load are performed using ADINA commercial finite element code. Complete equilibrium paths are traced up to collapse for nonlinear elastoplastic response of stiffened plates. Stiffened plates analysed are imperfect and their aspect ratio, plate slenderness and column slenderness are changed in a systematic manner. Different types of stiffener are chosen for stiffened plate models. Three different stiffener-to-plate welding procedures are considered: continuous, chain intermittent and staggered intermittent fillet welding. Copyright © 2006 by ASME. (9 refs.)

Keywords:  Plates (structural components)  -  Welds  -  Elastoplasticity  -  Numerical methods  -  Codes (symbols)  -  Loads (forces)

Secondary  Keywords:  Chain intermittent  -  Stiffened plate models  -  Equilibrium paths  -  Finite element codes

 


The dynamic response of gravity type quay wall during earthquake including soil-sea-structure interaction

Gharabaghi, A.R.M. (Civil Engineering Faculty, Sahand University of Technology); Ghalandarzadeh, A.; Arablouei, A.; Abedi, K. Source: Proceedings of the International Conference on Offshore Mechanics and Arctic Engineering - OMAE, v 2006, Proceedings of 25TH International Conference on Offshore Mechanics and Arctic Engineering, OMAE 2006, 2006, 10p

CODEN: PIOSEB

Conference: 25TH International Conference on Offshore Mechanics and Arctic Engineering, OMAE 2006, Jun 4-9 2006, Hamburg, Germany Sponsor: Ocean, Offshore, and Arctic Engineering Division of ASME

Publisher: American Society of Mechanical Engineers

Abstract: The dynamic response of gravity type quay wall during earthquake including soil-sea-structure interaction is calculated using ADINA finite element techniques. The main objective of this study is to investigate the effects of fluid-structure interaction on the residual displacement of wall after a real earthquake. A direct symmetric coupled formulation based on the fluid velocity potential is used to calculate the nonlinear hydrodynamic pressure of sea water acting on the wall. The doubly asymptotic approximation (DAA) is used to account for the effects of outer fluid on the inner region. The non-associated Mohr-Coulomb material behavior is applied to model the failure of soil. The full nonlinear effective stress analysis is performed in this study and the soil-pore fluid interaction effects are modeled using porous media formulation. Viscous boundary condition is implemented to model the artificial boundary in direct method analysis of soil-structure interaction system and sliding contact condition was modeled in the interface of wall and surrounding soil. A typical configuration of gravity quay wall is used for analysis and three real earthquakes excitation are applied as base acceleration. The results show that influence of fluid-structure interaction effects on the permanent displacement of a gravity quay wall constructed on relatively non-liquefiable site is not considerable. Copyright © 2006 by ASME. (22 refs.)

Keywords:  Quay walls  -  Dynamic response  -  Earthquake effects  -  Finite element method  -  Asymptotic stability  -  Stress analysis  -  Soils  -  Oceanography  -  Mathematical models

Secondary  Keywords:  Asymptotic approximation (DAA)  -  Hydrodynamic pressure  -  Residual displacement  -  Fluid velocity potential

 


Numerical simulation of the electromagnetic sheet metal bulging process

Wang, Lifeng (National Die and Mould CAD Engineering Research Center, Shanghai Jiao Tong University); Chen, Z.Y.; Li, C.X.; Huang, S.Y. Source: International Journal of Advanced Manufacturing Technology, v 30, n 5-6, September, 2006, Intelligent Disassembly in the Demanufacturing Process, p 395-400

ISSN: 0268-3768 CODEN: IJATEA

Publisher: Springer-Verlag London Ltd

Abstract: Electromagnetic forming (EMF) is an uncommon metal working process that relies on the use of electromagnetic forces to deform metallic workpieces at high speeds. It is expected to overcome some formability barriers of materials. EMF process analysis is the foundation of theoretical analysis. However, the electromagnetic sheet metal process is very difficult to describe, because of the complexity of magnetic pressure distribution. In this paper, a numerical modeling of the electromagnetic sheet metal process is performed using a finite element method, and a series of simulations on free bulging are carried out using the FEA program ADINA. The dynamic deformation process of sheet metal is investigated. At last, some experiments are made and those simulations agree well with the experimental results. (15 refs.)

Keywords:  Metal working  -  Sheet metal  -  Computer simulation  -  Electromagnetism  -  Electric potential  -  Large scale systems  -  Pressure distribution  -  Mathematical models  -  Finite element method

Secondary  Keywords:  Electromagnetic forming (EMF)  -  Bulging  -  Electromagnetic forces  -  Sheet metal process

 


An example of using FEM for air flow analysis through aircraft areal injector

Konieczny, A. (WSK PZL-Rzeszow S.A.) Source: Aviation, v 10, n 2, 2006, p 13-16+22

ISSN: 1648-7788

Publisher: Vilnius Gedminas Technical University

Abstract: In the article an example of using the Finite Element Method to determine the air distribution that is used in the atomization of fuel by the aerial injector is presented. In detail, Finite Element Method analysis appeared to be helpful in verifying the geometrical parameter of the injector - the two-flow parameter. The Finite Element Method results data of airflow distributions at the end of sections of an aerial injector allows a real geometric parameter to be verified. Full information about this parameter has shown the need to change other geometrical parameters. This work was made within the framework of a research project financed by State Committee for Scientific Research no. 5T12D 027 24. (3 refs.)

Keywords:  Finite element method  -  Aircraft engines  -  Atomization  -  Computational geometry  -  Project management  -  Engineering research

Secondary  Keywords:  Aerial injectors  -  Adina systems  -  Geometric parameters


Evaluation of some shear deformable shell elements

Laulusa, A. (Daniel Guggenheim School of Aerospace Engineering, Georgia Institute of Technology); Bauchau, O.A.; Choi, J-Y.; Tan, V.B.C.; Li, L. Source: International Journal of Solids and Structures, v 43, n 17, August, 2006, p 5033-5054

ISSN: 0020-7683

Publisher: Elsevier Ltd

Abstract: The objective of this paper is to evaluate a number of shell elements. At the same time, a new element is presented that is inspired by the quadrilateral heterosis element, Q8H, and is designated herein as the triangular heterosis element, T6H. Both elements employ the selectively reduced integration method. The elements investigated in this study include ABAQUS's three general-purpose shell elements, ANSYS's six-noded triangular element, T6, and the high-performance MITC9 element available in ADINA. The assessment is carried out by subjecting the various elements to several benchmark problems. It is found that for regular meshes, Q8H out-performs other elements and is comparable to MITC9. The performance of T6H is shown to be comparable to that of T6 in most test cases, but superior when very thin shells are considered. © 2005 Elsevier Ltd. All rights reserved. (33 refs.)

Keywords:  Shear deformation  -  Integration  -  Benchmarking  -  Finite element method  -  Mathematical models  -  Problem solving

Secondary Keywords:  Shells  -  Finite element models  -  Shear and membrane locking

 


Use of fiber-reinforced polymer composite elements to enhance structural steel member ductility

Accord, N.B. (Dept. of Civil and Environmental Engineering, Univ. of Pittsburgh); Earls, C.J. Source: Journal of Composites for Construction, v 10, n 4, 2006, p 337-344

ISSN: 1090-0268 CODEN: JCCOF2

Publisher: American Society of Civil Engineers

Abstract: An innovative use of fiber-reinforced polymer composite materials to control the manifestation of local buckling in a steel section during plastic hinging is discussed in the present work. This discussion focuses on a technique wherein the constituent plate components in a steel I-shaped cross section are braced against local plate buckling modes through the imposition of thin longitudinal strips whose function is to enforce a nodal line along a plate element. This work demonstrates that such an approach increases the critical load for individual steel plate elements and helps to constrain plastic flow for these same elements so that the structural ductility of the overall cross section is enhanced. The research work discussed herein is analytical in nature. Detailed nonlinear finite element models are created using traditional techniques implemented on the commercially available software system ADINA. Specifics pertaining to bond-line response are not treated. © ASCE. (10 refs.)

Keywords:  Fiber reinforced materials  -  Steel structures  -  Ductility  -  Buckling  -  Structural loads  -  Plates (structural components)  -  Computer software  -  Finite element method  -  Mathematical models

Secondary  Keywords:  Fiber reinforced polymers  -  Structural steel members  -  Plastic hinging  -  Plate buckling


Biocompatibile TiN-based novel nanocrystalline films

Ebner, R. (Materials Center Leoben); Lackner, J.M.; Waldhauser, W.; Major, R.; Czarnowska, E.; Kustosz, R.; Lacki, P.; Major, B. Source: Bulletin of the Polish Academy of Sciences: Technical Sciences, v 54, n 2, June, 2006, p 167-173

ISSN: 0239-7528

Publisher: Palac Kultury i Nauki

Abstract: Titanium nitride (TiN) is regarded as a potential biomaterial for blood-contact applications. TiN thin films were fabricated by pulsed laser deposition with the Nd:YAG laser on biologically applied polyurethane. Transmission electron microscopy (TEM) study of 250 nm thick films revealed columnar structure. Such films were observed to be brittle, which led to crack formation and secondary nucleation of microcolumn. TEM studies showed a kinetic mechanism of growth (columnar) in films of 250 nm thickness. It was stated that thinner films were much smoother and uniform than the thicker ones, which could be associated with the surface diffusion mechanism to appear. In order to improve the coatings elasticity, the thickness was reduced to 50 nm, which limited the deposition mechanism operation to the early stage. TEM cross-section observation revealed elastic properties of thin films. A biological test showed that TiN surface film produced on polyurethane is characterized by good biocompatibility and decreased surface affinity for cell adhesion. Films of 0.25 and 0.5 μm thick of TiN were selected for theoretical finite element modelling (FEM) using ADINA program. The micro cracks formation predicted in simulation was verified by phenomena observed in microstructure examinations. (17 refs.)

Keywords:  Nanostructured materials  -  Titanium nitride  -  Biocompatibility  -  Transmission electron microscopy  -  Pulsed laser applications  -  Thin films  -  Microstrip antennas

Secondary  Keywords:  Nanocrystalline films  -  ADINA program  -  Surface diffusion mechanism

 


Modelling of nanoindentation to simulate thin layer behaviour

Major, R. (Institute of Metallurgy and Materials Science, Polish Academy of Sciences); Lacki, P.; Lackner, J.M.; Major, B. Source: Bulletin of the Polish Academy of Sciences: Technical Sciences, v 54, n 2, June, 2006, p 189-198

ISSN: 0239-7528

Publisher: Palac Kultury i Nauki

Abstract: The work presents a computer simulation realized with the ADINA program concerning nanoindendation test. A shape of nanoindenter was proposed to be similar to the real surgical tools. The theoretical model was used to predict phenomena which would appear in practice. The contribution of the TiN coating thickness to the implant rigid properties was simulated. Three types of extortion conditions could be considered, i.e., short contact with surgery tool (i); long continuous contact with natural tissue (ii); long cyclic contact with natural tissue (iii). In the first part of the work, the authors focused on the first type of extortion (i). The second part of the work is dedicated to the calculations of temperature impact to layer behaviour, Two layer thicknesses are considered i.e., 250 nm and 50 nm. The examined coatings find serious practical applications as a blood-contacting material in medicine. The coatings were subjected to transmission electron microscopy investigations. Columnar mechanism of film growth controlled by kinetic process is stated to operate for the considered range of layer thickness. Plasma temperature is observed to influence the substrate behaviour. Examinations of thinner layers, i.e. under 100nm, revealed higher degree of smoothness and uniformity, which could be related to the operation of the surface diffusion mechanism at the early stage of deposition. The physical explanation of TEM images was based on the finite element calculations of the temperature distribution using the ADINA program. (13 refs.)

Keywords:  Thin films  -  Nanotechnology  -  Mathematical models  -  Computer simulation  -  Titanium nitride  -  Surgical equipment  -  Blood  -  Deposition  -  Transmission electron microscopy  -  Finite element method

Secondary  Keywords:  Columnar mechanism  -  ADINA program  -  Nanoindenter  -  Blood-contacting material  -  Nanoindentation

 

Validation Of A New Soil Constitutive Model For Cyclic Loading By FEM Analysis

G. Abate, C. Caruso, M. R. Massimino, M. Maugeri

Department of Geotechnical Engineering, University of Catania, 95125 Ct, Italy

Soil Stress-Strain Behavior: Measurement, Modeling and Analysis, 759–768, 2006.

Abstract: Nowadays, there is an increasing need to understand the behaviour of geotechnical structures during earthquakes. The damage caused by the recent earthquakes has shown that the local geology and the geotechnical characteristics of the foundation soil can influence significantly the seismic response of structures. So, in order to correctly predict the behaviour of a structure subjected to an earthquake, it is necessary to focus attention on the dynamic soil behaviour. In general, very simple soil constitutive models are implemented in commercial codes. Several studies have shown that when shear strains in the soil are small, it is possible to use the elastic-linear model; for medium strains it is convenient to use equivalent linear or nonlinear models. Elastic-plastic models, incrementally nonlinear models or hypoplastic models can more accurately capture response for sites that experience higher strains. A recent elasto-plastic constitutive model including both isotropic and kinematic hardening has been implemented in a FEM code. The numerical results achieved by the new version of the FEM code, are discussed and validated by means of the comparison with laboratory experimental results involving sands of different relative densities. An interesting parametric analysis is also presented, in order to investigate the effects of the implemented constitutive model parameter variation in the soil cyclic behaviour.


Biocompatibile TiN-based novel nanocrystalline films

R. Ebner1, J.M. Lackner2, W. Waldhauser2, R. Major3, E. Czarnowska4, R. Kustosz5, P. Lacki6, and B. Major3

1 Materials Center Leoben, A-8700 Leoben, Franz-Josef St.13, Austria
2 Joanneum Research Forschungsgesellschaft, Laser Center Leoben, A-8712 Niklasdorf, Austria
3 Institute of Metallurgy and Materials Science, Polish Academy of Sciences, 25 Reymonta St., PL 30-059 Cracow, Poland
4 The Children Memorial Health Institute, Department of Pathology, 20 Dzieci Polskich Ave, 04-736 Warsaw, Poland
5 Foundation of Cardiac Surgery Development, 345a Wolnosci St., 41-800 Zabrze, Poland
6 Czestochowa University of Technology, 19 Armii Krajowej Ave, 42-200 Czestochowa, Poland

Bulletin Of The Polish Academy Of Sciences Technical Sciences, 54(2):167-173, 2006.

Abstract: Titanium nitride (TiN) is regarded as a potential biomaterial for blood-contact applications. TiN thin films were fabricated by pulsed laser deposition with the Nd:YAG laser on biologically applied polyurethane. Transmission electron microscopy (TEM) study of 250 nanometer thick films revealed columnar structure. Such films were observed to be brittle, which led to crack formation and secondary nucleation of microcolumn. TEM studies showed a kinetic mechanism of growth (columnar) in films of 250 nanometer thickness. It was stated that thinner films were much smoother and uniform than the thicker ones, which could be associated with the surface diffusion mechanism to appear. In order to improve the coatings elasticity, the thickness was reduced to 50 nanometers, which limited the deposition mechanism operation to the early stage. TEM cross-section observation revealed elastic properties of thin films. A biological test showed that TiN surface film produced on polyurethane is characterized by good biocompatibility and decreased surface affinity for cell adhesion. Films of 0.25 and 0.5 micrometers thick of TiN were selected for theoretical finite element modelling (FEM) using ADINA program. The micro cracks formation predicted in simulation was verified by phenomena observed in microstructure examinations.

Key words: titanium nitride - thin films – polyurethane – biocompatibility - finite element modelling

 



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