ADINA Publications

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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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Assessment of long-term deformations of Ataturk Dam

S. Malla1, M. Wieland2, R. Straubhaar3

1,3 Senior Engineer, Poyry Energy Ltd., Hardturmstrasse 161, CH-8037 Zurich, Switzerland.
2 Chairman, ICOLD Committee on Seismic Aspects of Dam Design, Poyry Energy Ltd., Hardturmstrasse 161, CH-8037 Zurich, Switzerland.

Proc. of 1st National Symposium and Exposition on Dam Safety, Ankara, Turkey, 2007

Abstract: The 170 m high Ataturk rockfill dam was completed in 1990 and dam safety has been monitored continuously since then. The monitoring system comprises visual inspections, comprehensive geodetic surveys, and various types of sensors and instruments. For the safety monitoring, a detailed finite element (FE) model of a representative section of the dam was created, in which slip movements were allowed at the core-filter and filter-rockfill interfaces. The elasto-plastic model was assumed for the main dam materials. The material properties were determined based on laboratory tests, published data, and engineering judgment. Two basic load cases were considered, i.e. (i) dead load and (ii) water load. The geodetically measured dam displacements could be fitted satisfactorily with a linear combination, with time-dependent coefficients, of the computed displacements due to the gravity and water loads obtained from the FE analysis. It was further shown that the history of the time-dependent coefficients, which represented the creep-type post-construction deformations of the dam, could be fitted with asymptotic exponential trends. This model was calibrated based on displacements measured until the year 2000. The calibrated model was used to predict the dam displacements for a period of ten years. The dam displacements measured since 2001 show good agreement with the predicted values. This comparison of measured and predicted displacements is most beneficial for the safety monitoring of the Ataturk dam. The calibrated dam model allows an insight into the processes in the dam body that lead to the observed deformations of the dam surface. However, the physical phenomena responsible for the creep deformations have to be studied by separate laboratory tests. The possible effect of the increase of the reservoir water level on the dam deformations could also be estimated using the calibrated dam model.

Keywords: Rockfill dam - inelastic deformations - safety monitoring - dam analysis

 

Investigating stress concentration

M. Wieland1 and S. Malla2

1 Chairman, ICOLD Committee on Seismic Aspects of Dam Design, Poyry Energy Ltd., Hardturmstrasse 161, CH-8037 Zurich, Switzerland.
2 Poyry Energy Ltd., Hardturmstrasse 161, CH-8037 Zurich, Switzerland.

International Water Power & Dam Construction, January 2007

Abstract: Dr Martin Wieland and Dr Sujan Malla present the results of a detailed investigation of the stress concentration at a dam-foundation contact of a 250m high arch dam due to the water pressure, and discuss the effects of cracking on the three-dimensional behaviour.

On the initial configurations of collapsible channel flow

Xiaoyu Luo, Ben Calderhead, Haofei Liu, Wenguang Li

Department of Mathematics, University of Glasgow, UK

Computers and Structures,  85:977–987, 2007

Abstract:  This paper studies the effect of the initial configurations of the governing equations on flows in a collapsible channel where the upper elastic wall is replaced by a pre-stretched beam. The aim is to check the existence of a ‘‘tongue’’ shaped neutral stability curve in the Reynolds number–tension space from a fluid-beam model [Luo XY, Cai ZX. Effects of wall stiffness on the linear stability of flow in an elastic channel. In: de Langre E, Axisa F, editors. Proceedings of the eighth international conference on flow-induced vibrations, FIV2004, vol. II. Paris, France: 2004. pp. 167–70], in a properly formulated initial strain configuration. It was found that, for a given Reynolds number, as the tension is lowered to a critical value, the system becomes unstable, which is to be expected. However, a further decrease of the tension re-stabilizes the system before it becomes unstable again. It was possible that this puzzling finding was an artefact since the elastic equations used in the model were not properly derived from the zero initial stress configuration (Ogden, private communication). To check this, in this paper, a range of steady solutions are studied with both zero and non-zero initial wall tension. These are compared with the results using the finite element package ADINA 8.3 using both the initial strain and initial stress configurations. As expected, the fluid-beam model agrees with ADINA when using the initial stress configuration, but not when using the initial strain configuration. For cases with a small initial tension or small deformation (very large initial tension), both initial stress and initial strain configurations lead to very similar results, however, when the initial tension is comparable with the stretching induced tension, there are obvious differences in these two configurations. The ‘‘tongue’’ stability curve is then re-calculated with a zero initial tension, and re-plotted in the Reynolds number–effective tension space. It is interesting to see that though slightly different in shape, the ‘‘tongue’’ stable zone appears again when the zero initial tension is used. Thus it is highly likely that the puzzling ‘‘tongue’’ in the neutral stability curve is not due to the modelling approximation, but indicating a real, interesting physical phenomenon.

Keywords: Initial stress - Initial strain - Collapsible channel flow - Finite element methods - Neutral stability - Eigenvalue problem -  Fluid-structure interactions

 


Fluid-structure modeling of flow-induced alveolar epithelial cell deformation

H.L. Dailey1, H.C. Yalcin1, S.N. Ghadiali1,2

1Mechanical Engineering and Mechanics, Lehigh University, Rm. 265 Packard Lab, 19 Memorial Drive West, Bethlehem, PA 18015, USA
2Bio Engineering Program, Lehigh University, Bethlehem, PA 18015, USA

Computers and Structures,  85:1066–1071, 2007

Abstract: Fluid buildup in the small pulmonary airways can exert injurious stresses on the epithelial cells which line airway walls. Under these conditions, the amount of deformation-induced cell injury may depend on the magnitude of the hydrodynamic stresses and the cells’
mechanical properties. In this study, we present 2D and 3D fluid-structure interaction models of flow-induced cell deformation. We report wall shear stress on the cells and cell membrane strain for a range of cell and membrane stiffness values. Results indicate that more compliant cells experience lower wall shear stresses but higher membrane strains. We correlate our results to experimental studies of cellular injury under airway reopening conditions and validate our computational method by comparison to an analytical solution of flow over a rigid protrusion in a channel.

Keywords: Lung mechanics - Epithelial cell - Shear stress - Membrane strain – Deformation

 

The influence of cutting methods on the cut-surface quality of titanium sheets

Adamus, Janina (Technical University of Czestochowa) Source: Key Engineering Materials, v 344, Sheet Metal 2007: Proceedings of the 12th International Conference, 2007, p 185-192

ISSN: 1013-9826 CODEN: KEMAEY

Publisher: Trans Tech Publications Ltd

Abstract: In this paper, the influence of the cutting method on the cut-surface quality is analysed. A WT1-0 titanium sheet was cut in three different ways: using a guillotine, a laser and an abrasive-waterjet. The cut-surface's appearance, microstructure, microhardness and the roughness of the cutsurface were tested. Moreover, a numerical simulation of the banking process of a titanium disk was carried out with the ADINA System v.8.3 based on the finite element method. The influence of the radius of the cutting edge and the clearance on the surface quality was analysed. (12 refs.)

Keywords:  Sheet metal  -  Abrasives  -  Cutting  -  Jets  -  Laser pulses  -  Microhardness  -  Microstructure  -  Titanium

Secondary  Keywords:  Titanium sheets  -  Cut-surface quality

 


Optimisation of the stamping parameters of a drawn-part made of stainless steel

Piotr, Lacki (Technical University of Czestochowa) Source: Key Engineering Materials, v 344, Sheet Metal 2007: Proceedings of the 12th International Conference, 2007, p 349-355

ISSN: 1013-9826 CODEN: KEMAEY

Publisher: Trans Tech Publications Ltd

Abstract: Demand for an increase in the useable properties of a drawn-part made of stainless steel has been the inspiration for the work. The use of 4H13 steel instead of 3H13 has resulted in the higher strength of the drawn-part but also a decrease in drawability. Therefore, some modifications to the original design of the sheet-metal forming process were necessary. A numerical simulation was applied to optimise of the stamping process. The ADINA System based on the finite element method (MES) was used. Frictional conditions on the contact surfaces, blank diameter and the course of the blank holding force versus time were analysed. In this paper, the test results of the mechanical properties of the analysed sheets (3H13 and 4H13 stainless steel) are given, some differences in the way of stamping drawn-parts made of these materials are discussed and the results of the numerical simulation are presented. A 3D model and perfectly rigid tool were assumed in the numerical model. The sheet was modelled using shell elements. The elastic and plastic properties of the sheet material were assumed and the frictional conditions on the contact surfaces were taken into consideration during the numerical simulation. Based on the numerical simulation the stamping process was optimised. A comparison between the numerical calculation and test results shows good convergence. Thanks to the MES analysis and the application of the new technological parameters, the desired drawn-part with the better useable properties was obtained. (8 refs.)

Keywords:  Stainless steel  -  Computer simulation  -  Force control  -  Mathematical models  -  Metal drawing  -  Metal stamping  -  Steel sheet

Secondary  Keywords:  Medical tools  -  Sheet metal forming process  -  Technological parameters

 


Finite element simulation of elastohydrodynamic lubrication of soft biological tissues

Moghani, Taraneh (Department of Anesthesia and Critical Care, Beth Israel Deaconess Medical Center); Butler, James P.; Lin, Judy Li-Wen; Loring, Stephen H. Source: Computers and Structures, v 85, n 11-14, June/July, 2007, Fourth MIT Conference on Computational Fluid and Solid Mechanics, p 1114-1120

ISSN: 0045-7949 CODEN: CMSTCJ

Publisher: Elsevier Ltd

Abstract: In the serosal cavities (e.g. pleural, pericardial) soft tissues slide against each other, lubricated by thin fluid. We used rotational devices to study the tribology of such tissues, which appear to exhibit mixed and hydrodynamic lubrication. To explore mechanism, we modeled the interaction of fluid and soft material in 3D using a simple cylindrical geometry with an uneven solid-fluid interface in rotation. Deformation of the solid, frictional force, and fluid thickness are presented as a function of applied rotational velocity, applied normal load and material properties. The results suggest that the deformation caused by hydrodynamic pressure leads to load-supporting behavior. © 2007 Elsevier Ltd. All rights reserved. (11 refs.)

Keywords:  Tissue  -  Deformation  -  Elastohydrodynamic lubrication  -  Finite element method  -  Surface roughness  -  Three dimensional  -  Tribology

 

Secondary Keywords:  Soft biological tissues  -  ADINA  -  FSI  -  Soft materials  -  Rotational velocity

 


On the initial configurations of collapsible channel flow

Luo, Xiaoyu (Department of Mathematics, University of Glasgow); Calderhead, Ben; Liu, Haofei; Li, Wenguang Source: Computers and Structures, v 85, n 11-14, June/July, 2007, Fourth MIT Conference on Computational Fluid and Solid Mechanics, p 977-987

ISSN: 0045-7949 CODEN: CMSTCJ

Publisher: Elsevier Ltd

Abstract: This paper studies the effect of the initial configurations of the governing equations on flows in a collapsible channel where the upper elastic wall is replaced by a pre-stretched beam. The aim is to check the existence of a "tongue" shaped neutral stability curve in the Reynolds number-tension space from a fluid-beam model [Luo XY, Cai ZX. Effects of wall stiffness on the linear stability of flow in an elastic channel. In: de Langre E, Axisa F, editors. Proceedings of the eighth international conference on flow-induced vibrations, FIV2004, vol. II. Paris, France: 2004. p. 167-70], in a properly formulated initial strain configuration. It was found that, for a given Reynolds number, as the tension is lowered to a critical value, the system becomes unstable, which is to be expected. However, a further decrease of the tension re-stabilizes the system before it becomes unstable again. It was possible that this puzzling finding was an artefact since the elastic equations used in the model were not properly derived from the zero initial stress configuration (Ogden, private communication). To check this, in this paper, a range of steady solutions are studied with both zero and non-zero initial wall tension. These are compared with the results using the finite element package Adina 8.3 using both the initial strain and initial stress configurations. As expected, the fluid-beam model agrees with Adina when using the initial stress configuration, but not when using the initial strain configuration. For cases with a small initial tension or small deformation (very large initial tension), both initial stress and initial strain configurations lead to very similar results, however, when the initial tension is comparable with the stretching induced tension, there are obvious differences in these two configurations. The "tongue" stability curve is then re-calculated with a zero initial tension, and re-plotted in the Reynolds number-effective tension space. It is interesting to see that though slightly different in shape, the "tongue" stable zone appears again when the zero initial tension is used. Thus it is highly likely that the puzzling "tongue" in the neutral stability curve is not due to the modelling approximation, but indicating a real, interesting physical phenomenon. © 2006 Elsevier Ltd. All rights reserved. (31 refs.)

Keywords:  Channel flow  -  Eigenvalues and eigenfunctions  -  Finite element method  -  Fluid structure interaction  -  Reynolds number  -  Strain  -  Stress analysis  -  Wall flow

Secondary Keywords:  Initial stress  -  Initial strain  -  Collapsible channel flow  -  Neutral stability  -  Eigenvalue problem

 


In vivo MRI-based 3D FSI RV/LV models for human right ventricle and patch design for potential computer-aided surgery optimization

Yang, Chun (Mathematical Sciences Department, Worcester Polytechnic Institute); Tang, Dalin; Haber, Idith; Geva, Tal; del Nido, Pedro J. Source: Computers and Structures, v 85, n 11-14, June/July, 2007, Fourth MIT Conference on Computational Fluid and Solid Mechanics, p 988-997

ISSN: 0045-7949 CODEN: CMSTCJ

Publisher: Elsevier Ltd

Abstract: Right ventricular dysfunction is one of the more common causes of heart failure in patients with congenital heart defects. Use of computer-assisted procedures is becoming more popular in clinical decision making process and computer-aided surgeries. A 3D in vivo MRI-based RV/LV combination model with fluid-structure interaction (FSI), RV-LV interaction, and RV-patch interaction was introduced to perform mechanical analysis for human right ventricle with potential clinical applications. Patient-specific RV/LV morphologies were acquired by using planar tagged MRI. The 3D RV/LV FSI model was solved using a commercial finite element package ADINA. Our results indicated that flow and stress/strain distributions in the right ventricle are closely related to RV morphology, material properties and blood pressure conditions. Patches with material properties better matching RV tissue properties and smaller size lead to better RV function recoveries. Computational RV volumes showed very good agreement with MRI data (error less than or equal 3%). More patient studies are needed to establish baseline database so that computational simulations can be used to replace empirical and often risky clinical experimentation to examine the efficiency and suitability of various reconstructive procedures in diseased hearts and optimal design can be found. © 2006 Elsevier Ltd. All rights reserved. (16 refs.)

Keywords:  Medical computing  -  Blood  -  Fluid structure interaction  -  Magnetic resonance imaging  -  Surgery  -  Three dimensional  -  Tissue

Secondary  Keywords:  Human right ventricle  -  Heart model  -  Blood flow  -  Computer aided surgeries

 


Dynamic analysis of a water-soil-pore water coupling system

Wang, X. (Department of Civil Engineering, Louisiana Tech University); Wang, L.B. Source: Computers and Structures, v 85, n 11-14, June/July, 2007, Fourth MIT Conference on Computational Fluid and Solid Mechanics, p 1020-1031

ISSN: 0045-7949 CODEN: CMSTCJ

Publisher: Elsevier Ltd

Abstract: This paper explores the possible integration of the dynamic analyses of interaction of pore fluid flow and porous structure. The generalized fluid-structure interaction (FSI) algorithm in ADINA is applied for seismic analysis of a reservoir-earth dam-foundation system. In the given numerical example, water in the reservoir interacts with the earth dam on the upstream slope of the dam, and the foundation at the reservoir bottom. Pore water couples with soil particles throughout the earth dam and foundation. The reservoir water is modeled using both the Navier-Stokes equation based fluid element and the subsonic potential based fluid element. In the coupled analysis, hydrodynamic pressures and velocities are presented in the reservoir zone, while displacements, pore pressures and stresses are given for the earth dam and foundation domains at any earthquake time. The generalized FSI model is of great significance in performing soil liquefaction analysis if an appropriate soil plasticity model is employed in accounting for cyclic behavior of soils. © 2006 Elsevier Ltd. All rights reserved. (21 refs.)

Keywords:  Fluid structure interaction  -  Algorithms  -  Dynamic analysis  -  Elastoplasticity  -  Finite element method  -  Flow of fluids  -  Navier Stokes equations  -  Porous materials  -  Reservoirs (water)

Secondary Keywords:  Porous media models  -  Foundation system  -  Dam

 


Simulation of inelastic cyclic buckling behavior of steel box sections

Dicleli, Murat (Department of Engineering Sciences, Middle East Technical University); Mehta, Anshu Source: Computers and Structures, v 85, n 7-8, April, 2007, p 446-457

ISSN: 0045-7949 CODEN: CMSTCJ

Publisher: Elsevier Ltd

Abstract: In this study, a nonlinear structural model is developed to simulate the cyclic axial force-deformation behavior of steel braces including their buckling behavior using the commercially available nonlinear finite element based software ADINA. The nonlinear cyclic axial force-deformation simulation is done for braces with box sections. However, the structural model and simulation techniques described in this study may be applicable to braces with various section types using other commercially available structural analysis software capable of handling material and geometric nonlinearity. The developed nonlinear brace model is verified using available test results from the literature. It is found that the accuracy of the shapes of the analytical hysteresis loops and the energy dissipated compared to the experimental ones is satisfactory for analysis and design purposes in practice. The developed nonlinear brace structural model is then used to study the effect of various ground motion and structural parameters on the seismic response of single story, single bay concentrically braced frames with chevron braces. © 2006 Elsevier Ltd. All rights reserved. (16 refs.)

Keywords:  Structural frames  -  Buckling  -  Computational geometry  -  Computer simulation  -  Computer software  -  Deformation  -  Finite element method  -  Model structures  -  Steel structures

Secondary  Keywords:  Brace  -  Braced frames  -  Steel braces  -  Cyclic axial force-deformation

 

Stress state analysis in the femur after the implantation of the anatomical Centega type stem

Wojciech Wieckowski

Dept. of Biomedical Engineering, Czestochowa Univ. of Technology

Bio-algorithms and med-systems
Journal edited by Medical college – Jagiellonian University
Vol. 2, No. 3, 2006, pp. 49-61

Abstract: The relationship between the stiffness of the endoprosthesis stem and the bone stiffness, depending substantially on the geometrical and material features of the implant, influences significantly the long-lasting bio-functionality of the artificial hip joint. In this paper the results of the numerical FEM calculations of this stresses and strain energy density distribution in the bone tissue of the model of a proper femur and a femur after implantation of the modern anatomical stem of the Centega cement endoprosthesis have been presented. The results obtained from the calculations show significant influence of the implantation of the endoprosthesis stem on the change of loading transfer method in the bone region. The observed phenomenon is a main factor determining the adaptive processes occurring in the bone.

Key words: Centega endoprosthesis - hip joint alloplasty - FEM simulation

 

Computational analysis of the hemodynamics in cerebral arteries related to Moyamoya disease

Duk Chul Shin1, Ho Jun Seol2, Seung-Ki Kim3, Kyu-Chang Wang3, Byung-Kyu Cho3, Eun bo Shim1

1Department of Mechanical and Biomedical Engineering, Kangwon National University College of Engineering, Chuncheon, Korea
2Department of Neurosurgery, Kangwon National University College of Medicine, Chuncheon, Korea
3Department of Pediatric Neurosurgery, Seoul National University Children’s Hospital, Seoul, Korea

IFMBE Proceedings WC 2006 (World Congress on Medical Physics and Biomedical Engineering), Vol. 14, 2006, Seoul, Korea, CD

Abstract: Moyamoya disease (MMD) is characterized by bilateral intimal thickening of distal internal carotid arteries (ICA) and development of many collateral vessels in the base of the brain. Although the origin of MMD and the reason why it is limited to the major vessels remain unclear, it is believed that flow dynamics such as shear stress may be related to its smooth muscle cell migration. This study was performed to find out the local hemodynamic factor which concerns predominance of specific anatomic site such as distal internal carotid artery(ICA) and posterior cerebral artery (PCA) in progressed stages. We simulated the hemodynamics in cerebral arteries in circle of Willis using the computational models in two dimensional geometries of distal ICA and PCA. A finite element package, ADINA, was used to simulate the blood flow in these arteries. Numerical results showed that shear stress is relatively low at the ICA region. It was demonstrated that the shear stress distribution was related to the moyamoya disease.

Keywords: Moyamoya disease - Shear stress distribution - Computational analysis

 

A large-strain finite element formulation for biological tissues with application to mitral valve leaflet tissue mechanics

Eli J. Weinberga,b, Mohammad R. Kaazempur-Mofrada,c

aDepartment of Mechanical Engineering, Massachusetts Institute of Technology, Cambridge, MA, USA
bDraper Laboratory, Cambridge, MA, USA
cDepartment of Bioengineering, University of California, Berkeley, CA, USA

Journal of Biomechanics 39 (2006) 1557–1561

Abstract: This paper presents a finite element formulation suitable for large-strain modeling of biological tissues and uses this formulation to implement an accurate finite element model for mitral valve leaflet tissue. First, an experimentally derived strain energy function is obtained from literature. This function is implemented in finite elements using the mixed pressure-displacement formulation. A modification is made to aid in maintaining positive definiteness of the stiffness matrix at low strains. The numerical implementation is shown to be accurate in representing the analytical model of material behavior. The mixed formulation is useful for modeling of soft biological tissues in general, and the model presented here is applicable to finite element simulation of mitral valve mechanics.

Keywords: Biological tissues - Mitral valve - Large strain - Constitutive models - Finite element formulation

 

Unsteady flow and mass transfer in models of stenotic arteries considering fluid-structure interaction

Alvaro Valencia, Martin Villanueva

Department of Mechanical Engineering, Universidad de Chile, Casilla 2777, Santiago, Chile

International Communications in Heat and Mass Transfer 33 (2006) 966–975

Abstract: In this work the unsteady non-Newtonian blood flow and mass transfer in symmetric and non-symmetric stenotic arteries are numerically simulated considering the fluid-structure interaction (FSI) using the code ADINA. Blood with hyperviscosity syndrome is considered and hyperelastic Mooney–Rivlin model is used for the compliant arterial wall. The inlet boundary condition of imposed velocity or pressure is critical to obtain realistic hemodynamic results in stenotic arteries. The FSI affects significantly the hemodynamics on the stenotic arteries models, the arteries are considerably dilated and compressed due the stenosis. The stenosis severity and geometry have important influence on recirculation length, and distribution of concentration of macromolecules, such as low density lipoproteins (LDL).

Keywords: CFD - FSI - Stenosis - Blood flow - Artery compression - Artery dilatation

 

Fracture toughness of the +45 degree/ - 45 degree interface of a laminate composite

Leslie Banks-Sills, Yuval Freed, Rami Eliasi, Victor Fourman

Department of Solid Mechanics,  The Dreszer Fracture Mechanics Laboratory, School of Mechanical Engineering, The Fleischman Faculty of Engineering, Tel Aviv University, 69978 Ramat Aviv, Tel Aviv, Israel

Int J Fract (2006) 141:195–210

Abstract: Experiments are carried out to determine the delamination toughness for a crack along the interface between two transversely isotropic materials. The material chosen for study consists of carbon fibers embedded within an epoxy matrix. A crack is introduced between two layers of this material, with fibers in the upper layer along the +45 degree-direction and those in the lower layer along the –45 degree-direction both with respect to the crack plane. The Brazilian disk specimen is employed in the testing. To calibrate the specimens, stress intensity factors are obtained which result from the applied load, as well as residual curing stresses. It may be noted that all three modes are coupled, leading to a three-dimensional problem. The finite element method and a mechanical M-integral are employed to determine the stress intensity factors arising from the applied load. For the residual stresses, a three-dimensional conservative thermal M-integral is presented for stress intensity factor determination. The stress intensity factors found for the applied load and residual stresses are superposed to obtain a local energy release rate, together with two phase angles. From the load at fracture, the critical interface energy release rate or interface toughness Gicas a function of phase angles ψ and φ is determined. Results are compared to a fracture criterion.

Keywords: Delamination - Fracture toughness - Fiber-reinforced composite material - Three-dimensional conservative integrals - Finite elements, Thermal M-integral


Computer implementation of an orthotropic plate model for quick estimation of the maximum deflection of stiffened plates

Banai, Lior (School of Mechanical Engineering, Tel Aviv University); Pedatzur, Omri. Source: Ship and Offshore Structures, 2006 Vol. 1 No. 4 pp. 323–333 Language: English

ISSN: 1744-5302 (print); 1754-212X (online)

Publisher: Woodhead Publishing Ltd

Abstract: Stiffened plates form the backbone of most of a ship’s structure. They are, by far, the most commonly used structural elements in a ship, appearing in decks, bottoms, bulkheads and side shells. Stiffened plates are widely used because of their simplicity to fabricate and excellent strength-to-weight ratio. Today, finite element (FE) models are used to analyze the behavior of such structural elements for different types of loads. In the past, when use of computers and the FE models were not very much
in use, analytical analysis methods were required. The analysis of a stiffened plate, subjected to lateral loading, was based on one of two different types of models, namely, the orthotropic model and the grillage model. Both models estimated the maximum plate deflection under uniform lateral pressure. The objective of this paper is to implement an orthotropic model, on the basis of a series of papers published by H. A. Schade, as an algorithm/computer program for a fast structural analysis, without the aid of sometimes cumbersome finite element techniques. This will allow the user to quickly check if a plate can withstand applied loads, without the need to build the FE models, and to improve it if necessary (e.g., using more stiffeners or greater thickness).

Keywords: Stiffened panel/plate - maximum deflection - H. A. Schade - orthotropic model - grillage model

Secondary Keywords: finite element model - deck - bulkhead - side shell - lateral loading - ADINA

 

3D finite element analysis on bearing capacity characteristics of the composite ground

Liu, J. (Department of Civil Engineering, Zhuzhou Institute of Technology); He, J.; Ding, B.-Y. Source: Geotechnical Special Publication, n 152, Ground Modification and Seismic Mitigation - Proceedings of the GeoShanghai Conference, 2006, p 305-312

ISSN: 0895-0563 CODEN: GSPUER ISBN-10: 0784408645

Conference: Ground Modification and Seismic Mitigation - GeoShanghai Conference, Jun 6-8 2006, Shanghai, China

Publisher: American Society of Civil Engineers

Abstract: In this paper, a three dimensional elastic-plastic finite element model is established and employed to analyze the pile-soil-cap interaction of composite foundation. The behavior of the piles, the pile cap and surrounding soils are assumed to be linear elastic while the property of the soils beneath the pile cap is elastic-plastic. The infinite and interface elements are developed to simulate the remote soil and pile-soil interface properties, respectively. It is found that the reacting force at the corners of pile cop is the largest, the medium at the edges and the smallest at the internal parts. Moreover, reacting forces tend to be uniformly distributed as the external loads acting on the pile cap increases. The applicability and accuracy of the present method are verified by the results of a static load test on a nine-pile group under the pile cap and ADINA finite element program. It is observed that the present numerical results match very well with the experimental data. Copyright ASCE 2006. (6 refs.)

Keywords:  Finite element method  -  Bearing capacity  -  Composite structures  -  Computer simulation  -  Elasticity  -  Foundations  -  Soils

Secondary Keywords:  Elastic-plastic finite element model  -  Pile-soil-cap interaction  -  Soils beneath

 


Seismic response of landfills

Gatmiri, Behrouz (University of Tehran); Navidi, Sara Source: 5th ICEG Environmental Geotechnics: Opportunities, Challenges and Responsibilities for Environmental Geotechnics - Proceedings of the ISSMGE 5th Int. Congress, v II, 5th ICEG Environmental Geotechnics: Opportunities, Challenges and Responsibilities for Environmental Geotechnics - Proceedings of the ISSMGE 5th Int. Congress, 2006, p 1352-1358

Conference: 5th ICEG Environmental Geotechnics: Opportunities, Challenges and Responsibilities for Environmental Geotechnics - International Society of Soil Mechanics and Geotechnical Engineering's (ISSMGE) 5th International Congress, Jun 26-30 2006, Cardiff, Wales, United Kingdom

Publisher: Thomas Telford Services Ltd

Abstract: Despite the lack of well documented case histories of seismic response of landfills, some researchers have derived solid waste properties such as unit weight and initial shear wave velocity gradients by back-calculating the seismic response of some existent landfills. In this paper the results of the seismic response analyses using a finite element computer program, ADINA, are used to examine the response of solid waste landfills to seismic loading. Thus, a synthetic landfill which its geometry and dynamic properties of its material are selected based on existent information in literature is analyzed and the effects of three factors on its seismic response are studied. These factors include: 1- The peak acceleration of the input motion. 2- The width of the landfil. 3- The shear strength parameters of solid waste. The results of the analyses demonstrate that increasing the peak acceleration of the input motion, increases the values of calculated acceleration spectra in different points of the landfill. Moreover seismic response of landfills can be affected by the width of the landfill. The values of acceleration spectra decrease when the width of the landfill increases. On the other hand changing the shear strength parameters of solid waste (c,φ) don't influence seismic response of landfills. (18 refs.)

Keywords:  Land fill  -  Computational geometry  -  Finite element method  -  Parameter estimation  -  Seismic response  -  Solid wastes

Secondary  Keywords:  Solid waste properties  -  Unit weight  -  Shear wave velocity gradients  -  Finite element computer programs

 



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