Intro 2

 ANSYS

capabilities, basic ANSYS terminology, and the ANSYS GUI  How to perform a complete ANSYS analysis… the basic steps involved  Building or importing solid models and meshing  Applying loads, solving, and reviewing results  Productivity enhancement tools -- select logic, APDL, batch mode, etc.

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 Finite

What is FEA?

Element Analysis is a way to simulate loading conditions on a design and determine the design’s response to those conditions.  The design is modeled using discrete building blocks called elements. – Each element has exact equations that

Historical Note

describe how it responds to a certain load. – The “sum” of the response of all elements in the model gives the total response of the design. – The elements have a finite number of unknowns, hence the name finite elements.

• The finite element method of structural analysis was created by academic and industrial researchers during the 1950s and 1960s. • The underlying theory is over 100 years old, and was the basis for pen-and-paper calculations in the evaluation of suspension bridges and steam boilers.

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 The

finite element model, which has a finite number of unknowns, can only approximate the response of the physical system, which has infinite unknowns. – So the question arises: How good is the approximation? – Unfortunately, there is

no easy answer to this question. It depends entirely on what you are simulating and the tools you use for the simulation. We will, however, attempt to give you guidelines throughout this training course.

Physical System

F.E. Model

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Why is FEA needed?  To reduce the amount of prototype testing – Computer simulation allows multiple “what-if” scenarios

to be tested quickly and effectively.  To

simulate designs that are not suitable for prototype testing – Example: Surgical implants, such as an artificial knee

 The

bottom line:

– Cost savings – Time savings… reduce time to market! – Create more reliable, better-quality designs 4

 ANSYS

is a complete FEA software package used by engineers worldwide in virtually all fields of engineering: – Structural – Thermal – Fluid (CFD, Acoustics, and other fluid analyses) – Low- and High-Frequency Electromagnetics

A

partial list of industries in which ANSYS is used: – Electronics & Appliances

– Aerospace – Automotive

– Biomedical – Bridges & Buildings

– Heavy Equipment & Machinery – MEMS - Micro Electromechanical

Systems – Sporting Goods

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

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ANSYS Multiphysics is the flagship ANSYS product which includes all capabilities in all engineering disciplines. – ANSYS Classic Environment for exposure to all ANSYS functionality – ANSYS Workbench Environment for tight integration with CAD There are three main component products derived from ANSYS Multiphysics: – ANSYS Mechanical – structural & thermal capabilities – ANSYS Emag – electromagnetics – ANSYS FLOTRAN – CFD capabilities Other product lines: – ANSYS LS-DYNA – for highly nonlinear structural problems – ANSYS Professional – linear structural and thermal analyses, a subset of ANSYS Mechanical capabilities – ANSYS DesignSpace – linear structural and steady-state thermal analyses, a subset of ANSYS Mechanical capabilities in the Workbench Environment.

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ANSYS Professional

ANSYS Mechanical

ANSYS Multiphysics

ANSYS Emag

ANSYS Structural ANSYS ED

ANSYS DesignSpace

ANSYS FLOTRAN ANSYS LS-DYNA

ANSYS PrepPost

ANSYS University

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Workbench Modules: DesignModeler – Geometry editor of existing CAD models. DesignModeler is a parametric featured-based solid modeler designed so that you can intuitively and quickly begin drawing 2D sketches, modeling 3D parts, or attaching 3D CAD models for engineering analysis preprocessing. DesignXplorer – DesignXplorer is a powerful tool for designing and understanding the analysis response of parts and assemblies via the use of response surfaces. DesignXplorer is based on the Design of Experiments (DOE) optimization method, and uses parameters as its basic language. Using a Goals-Driven optimization method, DesignXplorer can obtain a multiplicity of robust design sets. DesignXplorer VT – Uses Variational Technology to provide a much more efficient approach than DOE in generating a response surface that is based on a single finite-element solve, combined with the use of mesh morphing, and the Taylor series expansion approximation. 8 Fatigue Module – Adds the capability to simulate performance under

Other products: ICEM CFD – preprocessing software used to create 3-D grids required by CFD and structural analyses. This product is offered by ICEM CFD (www.icemcfd.com), an ANSYS, Inc. subsidiary. ANSYS EMAX – high frequency electromagnetic analysis product. Combines the ICEM CFD preprocessor and postprocessor capabilities with the ANSYS, Inc. HF Electromagnetic solver. CFX – Suite of finite-volume-based CFD software, offered by CFX (http://www.software.aeat.com/cfx/), an ANSYS, Inc. subsidiary. AI*Nastran – NASTRAN solver developed by SAS LLC with dynamics and substructuring capabilities. ANSYS Workbench SDK – is an open and flexible new generation CAE focused application development platform from ANSYS, Inc. The technology components of this 9 platform can be used to create market-specific vertical

 Structural

analysis is used to determine deformations, strains, stresses, and reaction forces.

• Static analysis –Used for static loading conditions. –Nonlinear behavior such as large deflections, large strain, contact, plasticity, hyperelasticity, and creep can be simulated. Compression of a Hyperelastic Seal

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 Dynamic

analysis

– Includes mass and damping effects. – Modal analysis calculates natural frequencies and mode shapes. – Harmonic analysis determines a structure’s response to sinusoidal

loads of known amplitude and frequency. – Transient Dynamic analysis determines a structure’s response to time-varying loads and can include nonlinear behavior.  Other

structural capabilities

– Spectrum analysis – Random vibrations – Eigenvalue buckling – Substructuring, submodeling

Mode Shape Animation

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 Explicit

Dynamics with ANSYS/LS-DYNA

– Intended for very large deformation simulations where

inertia forces are dominant. – Used to simulate impact, crushing, rapid forming, etc.

Impact Analysis of a Vehicle Crash Test

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 Thermal

analysis is used to determine the temperature distribution in an object. Other quantities of interest include amount of heat lost or gained, thermal gradients, and thermal flux.  All three primary heat transfer modes can be simulated: conduction, convection, radiation.  Steady-State – Time-dependent effects are

ignored.  Transient – To determine temperatures, etc.

as a function of time. – Allows phase change (melting or freezing) to be simulated.

Transient Temperature of a Warming Clothes Iron

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 Electromagnetic

analysis is used to calculate magnetic fields in electromagnetic devices.  Static and low-frequency electromagnetics – To simulate devices operating with DC power sources,

low-frequency AC, or low-frequency transient signals. – Example: solenoid actuators,

motors, transformers – Quantities of interest include magnetic flux density, field intensity, magnetic forces and torques, impedance, inductance, eddy currents, power loss, and flux leakage. 14

 High-frequency

electromagnetics

– To simulate devices with propagating electromagnetic

waves. – Example: microwave and RF passive components, waveguides, coaxial connectors – Quantities of interest include S-parameters, Q-factor, Return loss, dielectric and conducting losses, and electric and magnetic fields.

Electric field (EFSUM) in a coaxial cable 15

 Electrostatics – To calculate the electric field from voltage or charge

excitation. – Example: High voltage devices, microelectromechanical systems (MEMS), transmission lines – Typical quantities of interest are electric field strength and capacitance.  Current

Conduction

– To calculate current in a conductor from an applied

voltage  Circuit

Coupling

– To couple electric circuits with electromagnetic devices 16

 Types

of electromagnetic analysis:

– Static analysis calculates magnetic fields due to direct

current (DC) or permanent magnets. – Harmonic analysis calculates magnetic fields due to alternating current (AC). – Transient analysis is used for time-varying magnetic fields.

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 Computational

Fluid Dynamics (CFD)

– To determine the flow distributions and temperatures in a

fluid. – ANSYS/FLOTRAN can simulate laminar and turbulent flow, compressible and incompressible flow, and multiple species. – Applications: aerospace, electronic packaging, automotive design – Typical quantities of interest are velocities, pressures, temperatures, and film coefficients.

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 Acoustics – To simulate the interaction between a fluid medium and

the surrounding solid. – Example: speakers, automobile interiors, sonars – Typical quantities of interest are pressure distribution, displacements, and natural frequencies.  Contained-Fluid

Analysis

– To simulate the effects of a contained, non-flowing fluid

and calculate hydrostatic pressures due to sloshing. – Example: oil tankers, other liquid containers  Heat

and Mass Transport

– A one-dimensional element is used to calculate the heat

generated by mass transport between two points, such as in a pipe. 19

 Coupled-Field

Analysis considers the mutual interaction between two or more fields. The fact that each field depends upon another makes it impossible to solve each separately, therefore you need a program that can solve both physics problems by combining them.

 Examples: – Thermal-stress analysis – Piezoelectrics (electric & structural ) – Acoustics (fluid & structural) – Thermal-electric analysis – Induction heating (magnetic and thermal) – Electrostatic-structural analysis

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