Resources

  • Acoustic Elements [ZIP]

    Sheldon Imaoka (ANSYS, Inc.)

    "For many years, ANSYS has 2D and 3D acoustic elements, including those used to model an “infinite” boundary. These elements can be used in modal, harmonic, and transient analyses, and fluid-structural interaction can also be accounted for in these simulations.

    This memo hopes to review the following topics related to harmonic acoustic analyses: basic comparison of structural and acoustic elements, modeling complex impedance boundary conditions, and defining complex pressure loading. A set of input files, which analyze the case of a simple radiating sphere, is included with this memo."

  • Acoustic Postprocessing [ZIP]

    Sheldon Imaoka (ANSYS, Inc.)

    "Acoustic analyses in ANSYS provides insight to the propagation of sound, and both visual and aural postprocessing can aid in this objective. This memo hopes to cover postprocessing methods for acoustic problems other than standard contour and XY plots."

  • Advanced Analysis Of Structural Reliability Using Commercial FE-Codes

    Christian Bucher, Dagmar Hintze, and Dirk Roos

    "The paper focuses on two main issues, i.e. (a) The application of existing code for probabilistic analysis together with existing Finite Element Code for advanced Monte Carlo analysis (b) Presentation of a local-global approximation strategy for the response surface method. This so-called "weighted radii" approximation appears to provide the flexibility and accuracy needed for the reliability analysis of complex structures." (Probabilistics)

  • Advanced Mask Modeling Accuracy and Stability Study-University of Wisconsin Mask Modeling

    R. Scott Mackay

    "As lithography error budgets on pattern placement become more stringent for sub-130 nm technology, it is imperative that all mask-related distortions be quantified, controlled, and minimized. It will be essential to identify the influence of thin film stress on pattern placement errors. In this research, the effect of mask material properties, manufacturing, and usage on image placement will be evaluated. Finite element (FE) models have been developed to simulate this pattern transfer process, using equivalent modeling techniques. Analytical, experimental, and FE procedures have been combined to accurately determine these effects on final pattern distortions."

  • Advanced Tools for Design and Analyses of High Temperature Cyclic Loaded Turbine Components

    U. Gampe, I. Martynov, J. Keyser

    "The paper presents a new concept to predict viscoplastic deformations in components under thermal mechanical loading. This approach is based both on material data from uniaxial creep tests and additional laboratory component tests to consider the influence of multiaxiality. This concept was used for analysis of feature tests of flat tensile specimens with central hole. The maximum test temperature was 600 °C and the surface of the hole was attacked by cyclic thermal shocks."(This paper refers to use of ANSYS User-Defined Materials. A related paper is Laboratory Component Testing for Investigation of Material Degradation from Creep-Fatigue Interaction.)

  • Advancing Analysis Capabilities In ANSYS Through Solver Technology

    Gene Poole, Yong-Cheng Liu, and Jan Mandel

    "This paper will describe implementation considerations for the addition of new solver technology to a large legacy code, compare resource requirements for the various solver choices and present some comparative results from several customer generated problems. The AMG solver benefits, both in improved robustness and parallel processing efficiency will be described. The paper will also discuss some of the implementation challenges that have been overcome to add new solver technology to a large existing code. The role of solver technology in meeting current and future demands of large scale commercial analysis codes will be discussed."

  • Algebraic Multigrid By Smoothed Aggregation For Second And Fourth Order Elliptic Problems

    Petr Van Ek, Jan Mandel, and Marian Brezina

    "An algebraic multigrid algorithm for symmetric, positive definite linear systems is developed based on the concept of prolongation by smoothed aggregation. Coarse levels are generated automatically. We present a set of requirements motivated heuristically by a convergence theory. The algorithm then attempts to satisfy the requirements. Input to the method are the coefficient matrix and zero energy modes, which are determined from nodal coordinates and knowledge of the differential equation. Efficiency of the resulting algorithm is demonstrated by computational results on real world problems from solid elasticity, plate bending, and shells."

  • An Approach to Combined Laplacian and Optimization-Based Smoothing for Triangular, Quadrilateral, and Quad-Dominant Meshes [PDF]

    Scott A. Canann, Joseph R. Tristano, Matthew L. Staten

    "In this paper, an overall mesh smoothing scheme is presented for meshes consisting of triangular, quadrilateral, or mixed triangular and quadrilateral elements. This paper describes an efficient and robust combination of constrained Laplacian smoothing together with an optimization-based smoothing algorithm."

  • An Architecture for Fluid/Structure Analysis of Turbomachinery Blading

    David A. Johnston, Charles J. Cross, J. Mitch Wolff

    "Aeroelastic stability and response analyses used in the design of turbomachinery blading are typically uncoupled: the unsteady aerodynamics and structural dynamics are treated in separate models, with boundary conditions sequentially updated after stationary periodic convergence is met. Higher fidelity simulations are achieved by coupling the fluid and structure domains such that boundary conditions are updated once or several times per physical time step of the simulation.""As a starting point, the turbomachinery CFD research code TURBO (Chen and Briley, 2001) and the commercial structural solver ANSYSŪ has been chosen for coupling, although FSI is designed with modularity for future inclusion of other fluid and structural solvers."
    [ANSYS Dynamics, version unspecified]

  • An Efficient FETI Implementation on Distributed Shared Memory Machines with Independent Numbers of Subdomains and Processors

    Michel Lesoinne and Kendall Pierson

    "Until now, many implementations of the FETI method have been designed either as sequential codes on a single CPU, or as parallel implementations with a One Subdomain per Processor approach. This approach has been particularly typical of implementations on distributed memory architectures such as the IBM SP2. In the last couple of years, several computer manufacturers have introduced new machines with a Distributed Shared Memory (DSM) programming model {e.g. SGI Origin 2000, or HP Exemplar. In such architectures, the physical memory is distributed among the processors or CPU boards but any memory location can be accessed logically by any CPU independently of where the particular memory page being accessed has physically been allocated. As more and more machines of this type are available with a relatively small number of processors, the interest in implementing FETI with an independent number of subdomains and processor has increased. We report on such an implementation of FETI and highlight the benefits of this feature. We have found that medium size to large problems can be solved even on a sequential machine with time and memory requirements that are one to two order of magnitude better than a direct solver."

  • An Interpretation of the Physics of Fluid-Structure Interaction in the Frequency Domain

    Jan Christian Anker

    "This paper constitutes an attempt to interpret the physics of FSI where the structure is vibrating. The structure considered is a very simple physical device, namely a flat cantilever plate. Many presumably important details are only briefly mentioned, other are left completely out of the discussion. The intention with the paper is to emphasize that there are cases where Fluid - Structure Interaction can be successfully simulated without having to utilize a Navier-Stokes Solver coupled with a (non-linear) Structural Analysis Program, a concept that requires vast amounts of computer time for linear vibrations (but is highly relevant for other applications)."

  • An Introduction to the Conjugate Gradient Method Without the Agonizing Pain

    Jonathan R. Shewchuk

    This paper presents a very well-written explanation of conjugate gradient methods. It is helpful in understanding better the idea behind CG solvers in ANSYS (PCG, JCG, ICCG, AMG, etc.).

  • An Investigation into Vibration in Switched Reluctance Motors

    Pragasen Pillay and William (Wei) Cai

    "Two disadvantages of the switched reluctance motor (SRM) are its torque ripple and acoustic noise. Previous work on vibration modes and resonant frequencies of the laminations of an 8-6 SRM is extended here to include the effects of the frame. Both a smooth frame and a ribbed frame are examined, and the presence of numerous additional vibratory modes in the ribbed frame demonstrated. Accelerometer tests behind a pole verify some of the theoretical predictions."[ANSYS Dynamics, version unspecified]

  • An Object Oriented Approach to Geometry Defeaturing for Finite Element Meshing [PDF]

    Anton V. Mobley, Michael P. Carroll, and Scott A. Canann

    "In this paper, an object-oriented approach to automatic geometry defeaturing is presented. The geometric and finite element data abstractions are given, along with the basic algorithms used."

  • Analysis Of Gasketed Flanges With Ordinary Elements Using APDL Control

    Yasumasa Shoji, Satoshi Nagata

    "The analysis of gasketted flanges is now becoming an essential technique to design pressure vessels or piping, because the design code is being modified. On the other hand, the gasket has an extreme nonlinearity which causes the analysis to be very difficult, especially using linear material properties. A finite element analysis program other than ANSYS has the element library for gasket element, but ANSYS does not have it yet."

    "The authors developed a method to model this nonlinear gasket by using the elements available in ANSYS Rel. 5.5 for 2-dimensional axisymmetric analysis and those in Rel. 5.6 for 3-dimensional analysis. In this paper, the concept and the procedure of the modeling is introduced. The data input is possible using a template, without using any other ANSYS commands. The whole analysis execution is controlled by APDL."

    [STI: Gasket elements are available from version 6.1 onwards, after this paper was written]

  • Analysis Of Reinforced Concrete Structures Using ANSYS Nonlinear Concrete Model

    Antonio F. Barbosa and Gabriel O. Ribeiro

    "This paper considers the practical application of nonlinear models in the analysis of reinforced concrete structures. The results of some analyses performed using the reinforced concrete model of the general purpose finite element code ANSYS are presented and discussed."

  • Analysis Of The FOREVER-Experiments Using A Finite Element Model

    Eberhard Altstadt, Thomas Moessner, Baj Ral Sehgal, Hans-Georg Willschütz

    "An axis-symmetric Finite Element (FE) model is developed based on the multi-purpose code ANSYS/Multiphysics. Using the Computational Fluid Dynamics (CFD) module the temperature field within the melt pool and within the vessel wall is evaluated. The transient structural mechanical calculations are then performed applying a creep model which takes into account large temperature, stress and strain variations." (Document 1)

  • Analysis and Modeling of Fiber-Wrapped Columns and Concrete-Filled Tubes

    Mohsen Shahawy, Tom Beitelman, and Amir Mirmiran

    "Carbon-wrapping of concrete column adds to its strength and ductility. The behavior of carbon-wrapped concrete is in general very similar to that of glass-wrapped concrete. The bilinear confinement that was developed- for glass-wrapped concrete can be applied to carbon-wrapped concrete. However, a better fit can be obtained by re-calibrating the model for an entire database that consists of both carbon-wrapped and glass-wrapped concrete. Such database needs to be accompanied by a set of accurate coupon tests on the properties of the jacket. The finite element modeling is also useful in predicting the response of carbon-wrapped concrete. A more accurate estimate of jacket properties make the analysis fit the test results better."

  • Analysis and Simulation of the Ultrasonic/Sonic Driller/Corer(USDC)

    X. Bao, Z. Chang, S. Sherrit, B.P. Dolgin, Y. Bar-Cohen, D.S. Pal, S. Du, T. Peterson

    "An ultrasonic/sonic driller/corer (USDC) was developed to address the challenges to the NASA objective of planetary in-situ rock sampling and analysis. The USDC uses a novel drive mechanism, transferring ultrasonic vibration into impacts on a drill stem at sonic frequency using a free-flying mass block (free-mass). The main parts of the device and the interactions between them were analyzed and numerically modeled to understand the drive mechanism and allow design of effective drilling mechanism. A computer program was developed to simulate the operation of the USDC and successfully predicted the characteristic behavior of the new device. This paper covers the theory, the analytical models and the algorithms that were developed and the predicted results."
    [ANSYS Piezoelectric, version 5.4]

  • Analysis and Testing of Graphite/Epoxy Concrete Bridge Girders Under Static Loading

    B. M. Kavlicoglu, F. Gordaninejad, M. Saiidi, Y. Jiang

    "An innovative graphite/epoxy-concrete (G/E-C) cross-section was developed and tested under two-point static loading. Finite element analysis and theoretical modeling of the cross-section was performed. The cross-section was a box girder with an outer G/E U-beam and inner G/E box beam with concrete webs and flange in between. Shear connection between G/E box beam and concrete slab was provided by a two-part structural epoxy resin. Additional shear connection was provided by steel stirrups located at 254 mm (10 in.) spacing along longitudinal axis of the test specimen. It was observed that, steel stirrups contributed the load carrying capacity after initiation of slippage between G/E beams and concrete. Moreover, a series of bond strength tests were performed to examine the behavior of structural epoxy resin for connection between G/E and concrete. Six G/E strips were subjected to tensile tests to evaluate the longitudinal and transverse elastic moduli of the laminate. Using the proper material properties and assumptions, it was possible to demonstrate the behavior of the section under static loads theoretically and in finite element analysis."
    [ANSYS Structural, version 5.5]

  • Analytical Modeling Of Glued Laminated Girder Bridges Using ANSYS

    Anil Kurian

    "This paper aims at developing a finite element model of glued laminated girder bridges that can predict accurately the analytical behavior of the bridges. Two models have been developed to study the characteristics of this type of bridge. Two case studies have been considered to validate the accuracy of the models. The first case study is a long span single-lane bridge, the Tuscaloosa Bridge, in Alabama. The second case study is a medium span two-lane bridge, the Cow Gu lch Bridge, in Montana. The models show good correlation with the experimental data and hence, the models can be used to find the maximum deflections in the bridge."Use of ANSYS 5.0 (1992 version)

  • Analytical Simulation of a 1D Single Crystal Silicon Electrostatic Micromirror [PDF]

    H. Camon, F. Larnaudie, F. Rivoirard, B. Jammes

    A torsional micromirror. Use of ANSYS to extract lumped parameters for use in SABER model. (MEMS)

  • Analyzing Hyperelastic Materials w/ Some Practical Considerations

    Paris Altidis and Vince Adams

    Presentation from the Midwest ANSYS User Group
    [ANSYS Nonlinear, version unspecified]

  • Analyzing Microminiature Devices [PDF]

    Steve Groothuis

    (from ANSYS Solutions magazine, volume 1, #1) (MEMS)

  • Anisotropic Plasticity and Failure Prediction in Wood Composites

    David M. Moses, Helmut G.L. Prion

    "Two case studies are summarized using anisotropic plasticity and the Weibull weakest link failure model to predict the behavior of wood and wood composites. The linear elastic orthotropic model normally used for wood is shown to be insufficient for the prediction of ultimate strength in wood. Non-linear, non-recoverable behavior in compression in each of the orthogonal material directions is of particular interest in cases where localized crushing governs the load-displacement behavior of wood."

    "The anisotropic plasticity option in ANSYS was used to predict yielding and post-yield behavior for the wood composite used in this study because yield stresses in orthogonal directions were found to be in the ratio of 1:1.2:5. A user-programmable Fortran subroutine was developed for ANSYS to carry out the failure analysis (and to calculate the volume integration of the stresses) at each load-step in post-processing. The model was verified using two cases: I) the ASTM D143 shear block test, and II) bolted connections."

  • Application of the Finite Element Method In Cold Forging Processes

    Cristina Maria Oliveira Lima Roque, Sérgio Tonini Button

    "In this study, the application of a commercial general finite element software - ANSYS - has been applied to model a forming operation. Models have been developed to simulate the ring compression test and to simulate a basic forming operation (upsetting) that is applied in most of the cold forging parts sequences." (Plasticity, contact, finite strain)

  • Applying Anand Model to Represent the Viscoplastic Deformation Behavior of Solder Alloys

    G. Z. Wang, Z. N. Cheng, K. Becker, J. Wilde

    "A unified viscoplastic constitutive law, the Anand model, was applied to represent the inelastic deformation behavior for solders used in electronic packaging. The material parameters of the constitutive relations for 62Sn36Pb2Ag, 60Sn40Pb, 96.5Sn3.5Ag, and 97.5Pb2.5Sn solders were determined from separated constitutive relations and experimental results. The achieved unified Anand model for solders were tested for constant strain rate testing, steady-state plastic flow and stress/strain responses under cyclic loading. It is concluded that the Anand model can be applied for representing the inelastic deformation behavior of solders at high homologous temperature and can be recommended for finite element simulation of the stress/strain responses of solder joints in service."
    [ANSYS Nonlinear, version unknown]

  • BMSweep: Locating Interior Nodes During Sweeping [PDF]

    Matthew L. Staten, Scott A. Canann, and Steve J. Owen

    "BMSweep is a new algorithm to determine the location of interior nodes while volume sweeping."

  • Basics of ANSYS Macros [PDF]

    David Haberman (CSI)

    Basics of creating and using macros (APDL) in ANSYS.

  • Basics on Structural Damping (Addendum) [ZIP]

    Sheldon Imaoka (ANSYS, Inc.)

    "Since ANSYS 5.6, there have been numerous enhancements as well as facets of the software program that have changed, including treatment of damping. This article is meant to serve as an addendum to Section 6 of the author’s "Structural Damping"memo, which was written in October, 2000."

  • Basics on Structural Damping [ZIP]

    Sheldon Imaoka (ANSYS, Inc.)

    This is an old document I wrote a while ago on damping which I sometimes use. Although written back at version 5.6, it is still applicable at version 7.0.
    "Damping is required in many dynamic applications, yet because there are many ways to include it, there is often confusion regarding the implementation of damping in ANSYS. This memo hopes to provide a general summary of the representation of damping available in ANSYS."

  • Behavioural modeling for heterogeneous systems based on FEM descriptions

    Joachim Haase, Sven Reitz, Peter Schwarz

    "To simulate more complex systems using Spice-compatible circuit and system simulation programs, behavioural models of the components are required. The focus of the paper is to discuss two possibilities to derive such models from FEM descriptions."

  • Benchmark Tests on ANSYS Parallel Processing Technology

    Kentaro Suzuki

    "ANSYS Inc. has released parallel processing solvers, DDS (Distributed Domain Solver) and AMG (Algebraic Multigrid Solver) in ANSYS version 5.7 in order to meet the requirements from the market."

    "In this paper, simple tests are first carried out to confirm the features and capabilities of DDS and AMG for different types of analyses. Furthermore, real-life problems such as thermal stress of an engine block (7.3 million DOF) and elastic-plastic-creep behavior of an IC packaging (about 84,000 DOF) are analyzed. The effectiveness of ANSYS parallel processing solvers is also studied."

  • Beta Electrical Contact Features at 6.0 [ZIP]

    Sheldon Imaoka (ANSYS, Inc.)

    "This issue describes a beta feature at 6.0, which is electrical contact capability of 17x surface-to-surface contact elements. This new capability allows contact in thermal-electric and structural-thermal-electric problems."
    (Week 13, week of 01/07/02.)

  • Biomechanical Interaction Between Cap Thickness, Lipid Core Composition and Blood Pressure in Vulnerable Coronary Plaque: Impact on Stability or Insta

    Gerard Finet, Jacques Ohayon and Gilles Rioufo

    "A ‘thin’ fibrous cap atheroma is the typical morphological characteristic of vulnerable plaque. Yet the very pathological studies that have provided these descriptions have also shown the actual prediction of plaque rupture to be rather less exact. Other relevant characteristics must be involved in the mechanisms of plaque rupture—blood pressure loading (P) and the material properties of the soft atheromatous core—as predictors of the distribution of the peak circumferential stress (PCS) locations."
    [ANSYS Structural, version 5.7]

  • Buckling in Workbench Simulation [PDF]

    Sheldon Imaoka (ANSYS, Inc.)

    "Buckling may be a concern for some situations, where a user may need to modify the design to prevent buckling within a given load range. Conversely, failure analysis may need to be performed when a structure has collapsed.
    ANSYS and Workbench Simulation have many tools to aid users in solving geometric instability problems, ranging from linear (eigenvalue) buckling to nonlinear, post-buckling analyses."
    (Week 41, week of 10/14/07)

  • Building Parametric Models [PDF]

    David Haberman (CSI)

    This memo provides an overview of APDL, defining parameters, and creating parametric models.

  • CERIG vs RBE3, RIGID184 [ZIP]

    Sheldon Imaoka (ANSYS, Inc.)

    "Constraint equations provide many useful features in ANSYS, such as tying together dissimilar meshes, representing parts of the system not explicitly modeled, or distributing loads. Two automated methods of generating constraint equations are the CERIG and RBE3 commands. Because there is often confusion over their use, this memo hopes to provide some information on differences between the two methods.
    "Constraint equations in ANSYS are linear, so they are not valid for large-rotation analyses. RIGID184 is a beta element in version 6.1 which provides rigid link/beam capabilities, valid for large-rotation problems. The latter part of this memo will cover some details of this undocumented feature, available in 6.1."

  • COMPMENU.zip

    Jim Patterson (Hendrickson Trailer Suspension Systems)

    "I have a set of macros to generate toolbars based on the defined components in the db. You can then call these toolbars from the main toolbar to aid in the selecting of the components. This includes "select", "also select", and "unselect". You can also "remake"the components from the toolbar. As someone who works with assemblies of shell models almost constantly, this has been a huge time saver for me."
    Tested on 5.7 through 6.1. Unzip the file and read the supplied Word document for instructions.

  • Calculating effective Coefficient of Thermal Expansion [PDF]

    Bill Bulat (CSI)

    Tips on how to define coefficient of thermal expansion and converting that material data to format that ANSYS can use.