ADINA Publications

Page 19

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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Seismic Soil-Tunnel-Structure Interaction Analysis And Retrofit Of The Posey-Webster Street Tunnels

A. Shamsabadi1, H. Sedara2, A. Kozak2

1Caltrans, Office of Earthquake Engineering
2SC Solutions

Proc. 2nd UJNR (United States and Japan Cooperative Program in Natural Resources) Workshop on Soil-Structure Interaction, Tsukuba, Japan, 2001

Abstract: The purpose of this paper is to present the Soil-Tunnel-Structure Interaction analysis performed for the “innovative” seismic retrofit of the Posey and Webster Street Tunnels located in the San Francisco Bay area. The tunnels are situated between two major faults, the Hayward Fault and the San Andreas Fault . Due to its close proximity to the site, the Hayward Fault is the controlling fault for the Safety Evaluation Earthquake (SEE) event. The Hayward Fault is capable of generating a peak horizontal rock acceleration of 0.76g, and horizontal ground accelerations in excess of 0.5g. The duration of the seismic event may exceed 45 seconds. The high peak rock acceleration of the design earthquake, and the long duration of the event, will allow the build-up of pore pressures. This could lead to extensive liquefaction with the consequent flotation of the tunnels resulting in a structural failure. The 1989 Loma Prieta earthquake (estimated horizontal ground acceleration of about 0.2g at the site) was the most recent major seismic event that occurred near the Posy and Webster Street Tunnels. The Post Earthquake Investigation report indicated evidence of liquefaction on the Island of Alameda and in the vicinity of the tunnels. Consequently, in 1997 ground improvement and retrofit of a number of structural components of tunnel segments became part of the retrofit plan for the tunnels. The ground improvement will prevent flotation of the tunnels, and the retrofit of structural components will prevent major damage to the tunnels themselves. Located at each end of the tunnel is a portal structure. It was necessary to design an opening between the portal structures and tunnels to reduce the tunnel-portal interaction. The retrofit strategy for the structural components is to provide flexibility and significantly reduce the forces in the tunnel segments. Response-spectrum-compatible rock motion time histories were developed along the tunnel alignment. The rock motions were propagated towards the surface to obtain the ground motion at the centerline of the tunnels for the Soil-Tunnel-Structure Interaction analysis. The objectives of the analysis were to estimate the responses of the as-built and retrofit configurations of the tunnels due to seismic excitations. In addition the global model racking analyses complements the global model.

 

Interaction between two adjacent panels at WIPP

S.J.Patchet1, R.C.Carrasco1, C.T. Francke2, R.Salari2 & S.Saeb2

1Westinghouse Government Environmental Services LLC, Carlsbad, New Mexico, USA
2RockSol Consulting Group, Inc, Boulder, Colorado, USA

Rock Mechanics in the National Interest, Elsworth, Tinucci & Heasley (eds), Swets & Zeitlinger Lisse, ISBN 90 2651 827 7, 2001

Abstract: The Waste Isolation Pilot Plant (WIPP), a Department of Energy (DOE) facility located in southeastern New Mexico near Carlsbad, is the first nuclear waste repository certified by the United States En- vironmental Protection Agency (EPA). The first waste disposal panel, Panel 1, was completed in 1988, and Panel 2 was completed in 2000. Although the geometry of Pand 2 is identical to that of Panel 1, the pattern of creep behavior of Panel 2 is anticipated to differ from that of Panel I because of its proximity to the first panel. Early in situ monitoring results appear to match a conceptual model of excavation performance. Two three-dimensional numerical models are being used to assess the interaction between Panel I and Panel 2 and have produced initial results.

Structure mechanics and thermal-hydraulic behaviour of a PWR coolant loop with a postulated crack like leakage

H. Grebner, C. Müller, J. Sievers

Gesellschaft für Anlagen- und Reaktorsicherheit (GRS ) mbH, Schwertnergasse 1, 50667 Cologne, Germany

Nuclear Engineering and Design, 205:219–225, 2001

Abstract: Thermal hydraulic calculations, using ATHLET, have been used to evaluate pressures and temperatures in primary and secondary circuits, following a postulated leak in the surge line. These were, then, used as input for the structural mechanics calculations with ADINA. The main results of the analyses may be summarised as follows; global deformations are significantly reduced by the drop in pressure and decrease in temperature (e.g. the vertical displacement of the surge line in the region of the crack is reduced by 50%); the leakage area at the end of the transient is about 30% lower compared with the value at the beginning; the leak rate is slightly increased at the end of the transient in comparison with the initial rate; the consideration of the crack surface pressure is important, as it leads to a significant increase in crack load and leakage area by about 50 and 35%, respectively.

 

On some aspects of fluid-structure interaction analysis with respect to aeroelasticity on industrial applications

R. Kroyer

EADS Germany GmbH, LFK-Defense and Civil Systems, 85705 Unterschleißheim,
Postfach 1661, Germany

Proc.First MIT Conference on Computational Fluid and Solid Mechanics, 2:1272-1277, 2001

Abstract: For the design of highly stressed aerodynamic control surfaces, i.e. fins, of subsonic and hypersonic flight vehicles the use of numerical methods like FEM and CFD, solving the Navier–Stokes equations, will be necessary. With respect to aeroelastic effects, the coupling of both methods to fluid–structure interaction (FSI) capabilities will lead to tremendous new possibilities in engineering applications for industrial use. Regarding the complex mathematical and numerical background of FSI, the new methods have to be tested and verified stepwise on real projects to evaluate the reliability of the new possibilities. On some fin structures models for a subsonic flight vehicle and a hypersonic flight vehicle the fluid–structure interaction capabilities of ADINA will be presented and discussed.

Keywords: Missile fins — EM/CFD — Fluid-structure interaction — Aeroelasticity

 

Self-strengthening research of fiber reinforced pressure vessel with metallic liners

Wang, X. (Department of Engineering Mechanics, School of Civil Eng. and Mechanics, Shanghai Jiaotong University); Li, M.D.; Yu, Z.Y. Source: Journal of Reinforced Plastics and Composites, v 20, n 16, 2001, p 1390-1413

ISSN: 0731-6844 CODEN: JRPCDW

Publisher: SAGE Publications Ltd

Abstract: On the basis of an elasto-plastic analytical solution for laminating structure, making use of automatic dynamic increment nonlinear finite element analysis software ADINA [1], the self-strengthening research of a FRP (fiber reinforced pressure) vessel with metallic liner is presented in this paper. A self-strengthening pressure is determined to make the aluminum inner layer elastic deformation under hydrostatic pressure and to obtain the best ratio of the vessel's volume and weight. Thus, the gas-tightness and fatigue strength of FRP vessel were improved. In addition, the influence of thermal load on the vessel was also calculated.

Keywords:  Pressure vessels  -  Fiber reinforced materials  -  Laminates  -  Elasticity  -  Plasticity  -  Pressure effects  -  Deformation  -  Hydrostatic pressure  -  Thermal load  -  Fatigue of materials  -  Finite element method

Secondary  Keywords:  Metallic liners

 

 

The Impact of Calcification on the Biomechanical Stability of Atherosclerotic Plaques

Hayden Huang3, Renu Virmani4, Hesham Younis2, Allen P. Burke4, Roger D. Kamm2,  Richard T. Lee1,2

1Cardiovascular Division, Department of Medicine, Brigham and Women’s Hospital, Harvard Medical School, Boston, MA;
2Center for Biomedical Engineering, Massachusetts Institute of Technology, Cambridge, MA;
3Health Sciences Technology Division of the Massachusetts Institute of Technology, Cambridge, MA;
4Department of Cardiovascular Pathology, Armed Forces Institute of Pathology, Washington, DC.

Circulation. 2001;103:1051-1056.

Abstract:
Background: Increased biomechanical stresses in the fibrous cap of atherosclerotic plaques contribute to plaque rupture and, consequently, to thrombosis and myocardial infarction. Thin fibrous caps and large lipid pools are important determinants of increased plaque stresses. Although coronary calcification is associated with worse cardiovascular prognosis, the relationship between atheroma calcification and stresses is incompletely described.
Methods and Result: To test the hypothesis that calcification impacts biomechanical stresses in human atherosclerotic lesions, we studied 20 human coronary lesions with techniques that have previously been shown to predict plaque rupture locations accurately. Ten ruptured and 10 stable lesions derived from post mortem coronary arteries were studied using large-strain finite element analysis. Maximum stress was not correlated with percentage of calcification, but it was positively correlated with the percentage of lipid (P=0.024). When calcification was eliminated and replaced with fibrous plaque, stress changed insignificantly; the median increase in stress for all specimens was 0.1% (range, 0% to 8%; P=0.85). In contrast, stress decreased by a median of 26% (range, 1% to 78%; P=0.02) when lipid was replaced with fibrous plaque.
Conclusions:Calcification does not increase fibrous cap stress in typical ruptured or stable human coronary atherosclerotic lesions. In contrast to lipid pools, which dramatically increase stresses, calcification does not seem to decrease the mechanical stability of the coronary atheroma.

Key Words: atherosclerosis - plaque - stress - calcification - lipids

 

 


Analysis of thermoelastic hydrodynamic lubrication performance of thrust bearing for large hydroelectric generator

Wu, Z.D. (Dep. of Elect. Mach., Harbin Inst. of Large Electr. Mach.); Wang, L.Q.; Qu, D.Z.; Qi, Y.L. Source: Mocaxue Xuebao/Tribology, v 21, n 2, March, 2001, p 147-150 Language: Chinese

ISSN: 1004-0595 CODEN: MAXUE7

Publisher: Science Press

Abstract: The thermoelastic-hydrodynamic lubrication performance of the thrust bearing with Babbitt layer and/or teflon layer of large hydroelectric generator was investigated by finite element analysis. The physical model takes the lubricating oil film, thrust bearing and runner and thrust head into account . The thermoelastic deformation of the thrust bearing and runner and thrust head was analyzed by using ADINA (T) program. It was found that the calculating results of the thrust bearings conform well to the measuring values.

Keywords:  Thrust bearings  -  Hydroelectric generators  -  Elastohydrodynamic lubrication  -  Deformation  -  Finite element method

Secondary Keywords:  Thermoelastic hydrodynamic lubrication  -  Thermoelastic deformation

 


Dynamic response analysis of fuel assembly with channel for nuclear heating reactor during seismic loading

Ju, Dezhong (Inst. of Nuclear Energy Technol., Tsinghua Univ.); Xu, Yong; Wang, Jiachun Source: Qinghua Daxue Xuebao/Journal of Tsinghua University, v 40, n 11, November, 2000, p 75-78 Language: Chinese

ISSN: 1000-0054 CODEN: QDXKE8

Publisher: Press of Tsinghua University

Abstract: The dynamic response of the fuel assembly and fuel channel interaction during a seismic event is analyzed to study the structural characteristics of the reactor fuel assembly as part of the Daqing NHR-200 project. The finite element program for automatic dynamic increment nonlinear analysis (ADINA) is used to predict the non linear dynamic response due to collisions between the fuel assembly and the fuel channel during seismic events. The results are used to analyze factors affecting the dynamic response, such as boundary support conditions and changes of the main model parameters. Curves are presented for the forces and frame displacements following the seismic excitation. The results verify the structural integrity of the fuel assembly including the channel in the NHR-200 design when subjected to seismic loading and verify that the cruciform control rod can still be inserted. (3 refs.)

Keywords:  Nuclear reactors  -  Heating  -  Nuclear fuel elements  -  Control nonlinearities  -  Dynamic response  -  Finite element method

Secondary  Keywords:  Nuclear heating reactors  -  Dynamic response analysis

 

 

Velocity/pressure mixed finite element and finite volume formulation with ALE descriptions for nonlinear fluid-structure interaction problems

X. Wang

Department of Mechanical Engineering, Polytechnic University, Brooklyn, NY 11201, United States

Advances in Engineering Software, 31:35-44, 2000

Abstract: In this article, we adopt a mixed upwinding procedure and the arbitrary Lagrangian-Eulerian (ALE) description to the velocity/pressure (v/p) mixed finite element formulation with high-order mixed elements. With this approach, we are able to accommodate the requirements for both the inf-sup condition and the upwinding technique in one self-adaptive finite element analysis. Some numerical examples are used to confirm the reliability of the formulation.

Keywords: Mixed upwinding procedure — Finite element formulation — Lagrangian–Eulerian description

 

 


Meso/micro-mechanical model for damage progression in glass-fiber/epoxy cross-ply laminates by finite-element analysis

Xia, Zihui (Univ of Alberta); Chen, Yu; Ellyin, Fernand Source: Composites Science and Technology, v 60, n 8, Jun, 2000, p 1171-1179

ISSN: 0266-3538 CODEN: CSTCEH

Publisher: Elsevier Science Ltd

Abstract: A three-dimensional multi-cell meso/micro-mechanical finite-element model has been developed for the prediction of the overall mechanical behavior of a glass-fiber/epoxy laminate, and for the study of damage mechanisms in fiber-reinforced polymer laminates. The epoxy matrix is represented by a non-linear viscoelastic constitutive model, which was incorporated into the finite-element analysis code, ADINA, through the user-defined subroutine. In addition, a damage criterion for the epoxy matrix is introduced into the finite-element model. Numerical results from the finite-element analysis are compared with experimental data, and it is found that both the predicted overall stress/strain response and the prediction of the initiation and propagation of the damage are in good agreement with the experimental results. (23 refs.)

Keywords:  Glass fiber reinforced plastics  -  Laminated composites  -  Nonmetallic matrix composites  -  Epoxy resins  -  Composite micromechanics  -  Mathematical models  -  Finite element method  -  Viscoelasticity  -  Stress analysis  -  Strain measurement  -  Crack initiation  -  Crack propagation  -  Computer simulation

Secondary  Keywords:  Mesomechanical model  -  Viscoelastic constitutive model  -  Fiber reinforced cross-ply laminates  -  Damage simulation


Validity of one-dimensional experimental principle for flat specimen in bar-bar tensile impact apparatus

Wang, C.Y. (Univ of Science and Technology of China); Xia, Y.M. Source: International Journal of Solids and Structures, v 37, n 24, Mar, 2000, p 3305-3322

ISSN: 0020-7683 CODEN: IJSOAD

Publisher: Elsevier Science Ltd

Abstract: The Bar-bar Tensile Impact Apparatus (BTIA) is widely used to measure the dynamic tensile properties of solid materials. In the present paper, a simplified three-dimensional finite element model for the BTIA system with a flat specimen is established to simulate the experimental process of a BTIA. The numerical solution for the model is solved by ADINA. In the scope of elastoplastic theory, the numerical analysis confirms the validity of the one-dimensional experimental principle used in the BTIA, as long as certain foundations are satisfied. (15 refs.)

Keywords:  Tensile testing  -  Structural analysis  -  Finite element method  -  Mathematical models  -  Elastoplasticity  -  Stress analysis

Secondary Keywords:  Bar-bar tensile impact apparatus (BTIA)

 


Nonlinear finite element analysis for the ultimate strength of multiplannar tubular joint

He, Dongzhe (Tsinghua Univ); Wang, Yuanqing; Li, Shaofu Source: Gong Cheng Li Xue/Engineering Mechanics, v 17, n 4, Aug, 2000, p 50-55 Language: Chinese

ISSN: 1000-4750 CODEN: GOLIEB

Publisher: Tsinghua University

Abstract: A four-node general quadrilateral shell element for geometric and materials non-linear analysis was employed in the modeling of tubular joint, an automatic incremental algorithm was adopted in the solution of nonlinear finite element equations. Based on the ADINA code, the preprocessing and post-processing programs were developed, which reduced the computational cost of the ultimate strength of multiplannar tubular joints including joints between circular hollow sections, joints between square hollow sections and circular hollow sections. Numerical results were compared with the experimental results. Good agreement is achieved. (6 refs.)

Keywords:  Joints (structural components)  -  Finite element method  -  Shells (structures)  -  Nonlinear equations

Secondary  Keywords:  Tubular joint  -  Four node shell element  -  Automatic incremental algorithm  -  Ultimate strength  -  ADINA program


Three-dimensional analysis of bar-bar tensile impact testing apparatus with a flat specimen by elastoplastic FEM

Congyue, Wang (Univ of Science and Technology of China); Yuanming, Xia Source: Ying Yong Li Xue Xue Bao/Chinese Journal of Applied Mechanics, v 17, n 1, Mar, 2000, p 121-126 Language: Chinese

ISSN: 1000-4939 CODEN: YLXUFD

Publisher: Xi'an Jiaotong Univ

Abstract: In relation to reference, a three-dimensional finite element model for the SHTB is established to simulate the Bar-Bar Tensile Impact Testing Apparatus with a Flat Specimen. Using the finite element program ADINA, the first comprehensive 3-D numerical solution for the model is obtained. Numerical simulations indicate that, so long as certain conditions be satisfied, the 1-D experimental principle adopted in analyzing the experimental data can be confirmed. These conditions make it necessary to appropriately select the geometry of the specimen. Compared with the simulational experimental results for the SHTB with a dumbbell-like cylindrical specimen, this SHTB with a dumbbell-like flat specimen is more reliable and reasonable.


3-D computational fluid dynamics in artificial lung design: steady and transient models

Chambers, S.D. (Michigan Critical Care Consultants, Inc); Bartlett, R.H.; Montoya, J.P. Source: ASAIO Journal, v 46, n 2, Mar-Apr, 2000, p 231

ISSN: 1058-2916 CODEN: ASATEJ

Conference: 46th Annual Conference and Exposition of ASAIO, Jun 28-Jul 1 2000, New York, NY, USA

Publisher: Lippincott-Raven Publ

Abstract: A 3-D Computational Fluid Dynamic (CFD) model of a previously described total artificial lung (TAL) was developed. The model was developed to optimize the TAL design based on three parameters: flow distribution, pressure drop (DP), and lung impedance in pulsatile flow. METHODS: ADINA (ADINA R&D, Inc., Watertown, MA), a finite-element based package, was used in this work. The fiber bundle was assumed to be a porous medium, and thus, modeled using Darcy's equations. The porosity (j=0.5) was calculated from the fiber geometry and spacing, and the permeability (k=7.4e-9m2) was measured experimentally. For this preliminary work, the fluid was water (r=1000 kg/m3, m=0.001 Ns/m2). For steady-state flow, DP was prescribed as the boundary condition. For transient flow, physiologic inlet and outlet pressures were prescribed as functions of time. RESULTS: For the initial TAL design, the calculated steady-state flow rate (Q) vs. DP was within 5-20% of the measured Q up to 10 l/min. Several design alterations were studied, and the CFD results trended with the measured Q vs. DP. For the transient model, the calculated Q(t) was within 10-15% of that measured. CONCLUSIONS: These preliminary results suggest that CFD will be a useful tool in hemodynamic optimization of the TAL. Also, the transient model will allow for the TAL impedance to be optimized, while minimizing the need for trial and error device prototyping.

Keywords:  Artificial organs  -  Computational fluid dynamics  -  Pulsatile flow  -  Mathematical models  -  Physiology  -  Hemodynamics  -  Optimization  -  Computer aided design

Secondary Keywords:  Artificial lung  -  Flow distribution  -  Lung impedance

 


Dynamic elastic buckling of a slender beam with geometric imperfections subject to an axial impulse

Kenny, S. (Dalhousie Univ); Pegg, N.; Taheri, F. Source: Finite Elements in Analysis and Design, v 35, n 3, Jun, 2000, p 227-246

ISSN: 0168-874X CODEN: FEADEU

Publisher: Elsevier Science B.V.

Abstract: Results from a numerical investigation of the dynamic buckling of an elastic slender beam, with initial geometric imperfections, subjected to an intense axial impulse are presented. The pulse buckling response was numerically modelled via the finite difference and finite element methods. Three commercially available software packages were utilized during the investigations: ADINA (Users Manual, ADINA R&D, Inc., 71 Elton Avenue, Watertown, MA, 02172, USA, September 1990 (http://world.std.com to approximately adina/).) ANSYS (Users Manual, Ver. 5.3, Troy Technology Park, 1960 Ring Drive, Troy, MI, 48083, USA, SAS IP Inc., 1997 (http://www.ansys.com).) and NISA (Users Manual, Ver. 7, Engineering Mechanics Research Corporation, P.O. box 696, Troy, MI 48099, USA, 1997 (http://www.emrc.com).). The analysis demonstrated that only random geometric imperfections would initiate the characteristic exponential growth of transverse buckling displacements. Accurate modelling of the peak buckling amplitude and modal response required aspect ratios in the order of 1:1. The finite difference models were consistent with theory. The performance of quadratic, plane strain finite element models was superior to that using beam elements. This was related to the inherent curvature restrictions defined through the Euler-Bernoulli beam element formulation. A buckling criterion based on critical load intensity was investigated. Details on the numerical models, computations and analyses are presented. (19 refs.)

Keywords:  Beams and girders  -  Buckling  -  Elasticity  -  Finite element method  -  Finite difference method  -  Dynamic response  -  Computer aided design  -  Computational geometry  -  Computer simulation  -  Mathematical models  -  Failure analysis

Secondary  Keywords:  Geometric imperfections  -  Software package ANSYS  -  Software package ADINA

 


Nonlinear finite element analysis for the ultimate strength of multiplannar tubular joint

He, Dong-zhe (Tsinghua Univ); Wang, Yuan-qing; Li, Shao-fu Source: Gong Cheng Li Xue/Engineering Mechanics, v 17, n 4, Aug, 2000, p 50-55 Language: Chinese

ISSN: 1000-4750 CODEN: GOLIEB

Publisher: Tsinghua University

Abstract: A four-node general quadrilateral shell element for geometric and material non-linear analysis is employed in the modeling of tubular joint, an automatic incremental algorithm is adopted in the solution of nonlinear finite element equations. Based on the ADINA code, the preprocessing and post-processing programs are developed, which reduce the computational cost of the ultimate strength of multiplannar tubular joints including joints between circular hollow sections, joints between square hollow sections and circular hollow sections. Numerical results are compared with to the experimental results. Good agreement is achieved. (6 refs.)

Keywords:  Joints (structural components)  -  Structural analysis  -  Strength of materials  -  Mathematical models  -  Finite element method  -  Algorithms  -  Computer aided analysis

Secondary  Keywords:  Ultimate strength  -  Software package ADINA

 


A two-dimensional axisymmetric numerical analysis of a bar-bar tensile impact apparatus by elastoplastic FEM

Wang, C.Y. (Department of Modern Mechanics, Univ. of Sci. and Technol. of China); Wan, H.P.; Xia, Y.M. Source: Journal of Sound and Vibration, v 220, n 5, Mar 11, 1999, p 787-806

ISSN: 0022-460X CODEN: JSVIAG

Publisher: Academic Press

Abstract: At present, a bar-bar Tensile Impact Apparatus (BTIA) is widely used to measure the dynamic tensile properties of solid materials. A BTIA consists of two long bars, between which a specimen is connected. Hence, there are several physical and geometric discontinuous sections in a BTIA. In the present paper, a two-dimensional axisymmetric elastoplastic finite element model for a BTIA with a dumb bell-shaped cylindrical specimen is established. The numerical solution for the model is solved by ADINA. In the scope of elastoplastic theory, the numerical analysis confirms the validity of the 1D experimental measuring principle of BTIA, so long as certain foundations are satisfied. The effects of the specimen geometry and strain rate are also discussed. The matching relation between the specimen and the BTIA system has been studied. (11 refs.)


Two-Dimensional Axisymmetric Analysis of Bar-Bar Tensile Impact Testing Apparatus by Elastoplastic FEM

Congyue, Wang; Yuanming, Xia Source: Ying Yong Li Xue Xue Bao/Chinese Journal of Applied Mechanics, v 16, n 1, 1999, p 65-73 Language: Chinese

ISSN: 1000-4939 CODEN: YLXUFD

Publisher: Xi'an Jiaotong University

Abstract: At present, a bar-bar tensile impact apparatus (SHTB) is widely used to measure the dynamic tensile properties of solid materials. SHTB consists of two long elastic bars, between which a specimen is glue-connected. Hence, there are several physical and geometric discontinuous sections in SHTB. In the present paper, the results of the first comprehensive two-dimensional (2D) numerical analysis of SHTB are obtained. A 2D axisymmetric elastoplastic finite element model for SHTB is established. The numerical solution for the model is solved by the dynamic incremental non-linear finite element program (ADINA). The numerical results show the rule of the stress wave propagation is SHTB and quantitatively describe the effects of variations in both the specimen geometry and the different strain-rate on the validity of the assumptions used in analyzing experimental data. In the scope of elastoplastic theory, the numerical analysis for SHTB shows that the validity of ID experimental measuring principle can also definitely be found out. Furthermore, the matching relation between the specimen and the SHTB system is discussed. (12 refs.)


Computational simulation of turbulent mixing with mass transfer

Wang, Xiaodong (Georgia Inst of Technology); Feng, Zhigang; Forney, Larry J. Source: Computers and Structures, v 70, n 4, Feb, 1999, p 447-465

ISSN: 0045-7949 CODEN: CMSTCJ

Publisher: Elsevier Sci Ltd

Abstract: In this paper, we present a series of computational simulations of three-dimensional turbulent mixing with mass transfer for various pipe mixing arrangements. The simulations are carried out with the ADINA software, in which general-purpose finite element and finite volume formulations along with the k-ε turbulent model are used for incompressible Navier-Stokes flows with mass transfer. Based on the predicted pressure and velocity profiles and the standard deviation of tracer (or fiber) spatial distributions at certain distances downstream from the injection point, we compare the mixing performances of various transverse, concentric, and multijet mixers as well as four silo mixing units. In addition, we deduce certain design information pertaining to different mixing configurations. (14 refs.)

Keywords:  Mixing  -  Mixers (machinery)  -  Jets  -  Turbulent flow  -  Mass transfer  -  Pipe  -  Computer simulation  -  Computer software  -  Finite element method  -  Finite volume method  -  Mathematical models  -  Machine design  -  Incompressible flow

Secondary  Keywords:  Software package ADINA  -  Turbulent mixing  -  Navier-Stokes flows

 


Fatigue testing of double-angle connections of steel railroad bridges

Abouelmaaty, Waled (Univ of Nevada-Reno); Maragakis, Emmanuel; Itani, Ahmad; Douglas, Bruce Source: Transportation Research Record, n 1688, Nov, 1999, p 46-52

ISSN: 0361-1981 CODEN: TRREDM

Publisher: National Research Council

Abstract: An experimental study to evaluate the fatigue strength of double-angle connections used to connect stringers to floor beams in steel railroad bridges is described. The tests examined connections that could be used for either new construction or replacement of old, damaged connections. Double-angle connections are always assumed to be subjected only to shear stresses. But, in reality, some bending moment also is developed by this type of connection, causing additional flexural stresses, which, in turn, can produce fatigue damage by exceeding the constant amplitude fatigue limit. The amount of the transferred moment was estimated in the tests. Two full-scale specimens were built, representing the stringer-to-floor beam connection of a one-span, open-deck, through-plate girder bridge located in Nevada, typical of construction in the early 1900s. The specimens were tested under a cyclic loading of &plusmn 195.8 kN, representing the equivalent load, which produces a total maximum shear reaction at the connection equal to the one produced in the actual bridge. However, the load cycles were from 0 to 391.6 kN in real bridges. The specimens also were tested beyond the fatigue initiation to observe the crack-propagation patterns and their growth rate. The tested specimens were modeled by the finite element program ADINA, and a comparison between the analytical and experimental results was made. (12 refs.)

Keywords:  Railroad bridges  -  Steel bridges  -  Fatigue testing  -  Connectors (structural)  -  Structural analysis  -  Strength of materials  -  Fatigue of materials  -  Shear stress  -  Bending moments  -  Numerical methods  -  Cyclic loads  -  Crack propagation  -  Finite element method

Secondary  Keywords:  Double angle connections  -  Steel railroad bridges  -  Flexural stresses  -  Fatigue damage

 


Seismic analysis of a fire loop piping system

Crawford, J.E. (Karegozian & Case Structural Engineers); Constantino, C.J.; Goen, L.K.; Volkman, D. Source: American Society of Mechanical Engineers, Pressure Vessels and Piping Division (Publication) PVP, v 387, 1999, p 249-254

ISSN: 0277-027X CODEN: AMPPD5

Conference: Seismic Engineering - 1999 (The ASME Pressure Vessels and Piping Conference), Aug 1-Aug 5 1999, Boston, MA, USA Sponsor: ASME

Publisher: American Society of Mechanical Engineers

Abstract: This paper summarizes the studies conducted to assess the seismic capability of a fire loop piping system that is being installed at the Los Alamos National Laboratory (LANL) to serve a series of critical facilities. The approach used in the evaluation was to develop a complete finite element model of the entire fire loop piping system and its appurtenances extent to the structures being protected. The seismic loading was input to this system in the form of specified accelerograms selected to match given response spectral criteria. The system responses were then computed using the ADINA nonlinear finite element program, incorporating several nonlinear aspects relating to pipe-soil interaction and pipe bending. A series of calculations were performed to assess the effects of direction of the seismic input, potential variability in site parameters as well as materials of the piping system. Calculations of response were performed for both ductile iron (DI) and high-density polyethylene (HDPE) pipe. (12 refs.)

Keywords:  Water piping systems  -  Earthquake resistance  -  Structural analysis  -  Structural loads  -  Computer simulation  -  Mathematical models  -  Finite element method  -  Computer software  -  Soil structure interactions  -  Bending (deformation)  -  Nodular iron  -  Plastic pipe  -  High density polyethylenes

Secondary  Keywords:  Fire loop piping systems  -  Accelerograms  -  Response spectral criteria  -  Software package ADINA

 



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