ADINA System NewsletterVolume 4, Issue 2 www.adina.com December 2001

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Training Classes

The next ADINA-AUI training course will beheld at ADINA R & D on January 24-25, 2002.

INSIDE THIS ISSUE

� ADINA System 7.5 Updates

� Analysis of Disc Braking System

� Analysis of Rubber Seal

� ADINA System 7.6 Developments

Season�s Greetings

Once again, we have come to the end of anotheryear. First, we would like to wish you a HappyHoliday Season and a good New Year ahead.

Although the economy is currently going throughsome rough times, we are glad to let you know thatADINA R & D continues to grow. We believe thekey to our success is that we have a team of highlyqualified professionals in an environment thatfosters collaboration, commitment, and excellence.

We are committed to provide all our users the besttool and support for their analyses. In this Newslet-ter, we mention some updates for ADINA 7.5 andpresent an overview of our development efforts forimprovements in ADINA 7.6.

ADINA System 7.5 Updates

ADINA 7.5.2 is now available. This version fixesbugs found from ADINA 7.5.0 onwards. The list ofbugs fixed for each of the program modules isgiven on the Support > Download page of our website. In this web page, you can download the PCWindows version of the program executables forADINA 7.5.2. Please note that a password isrequired to access this web page and currentusers can contact us to obtain the password.

There are also some updates regarding our CADinterface programs.

� TRANSOR for PatranTRANSOR for Patran is now available forMSC.Patran 2001r2. Unix versions can bedownloaded from the download page of our website. The PC Windows version is provided in anupdated CD.

� TRANSOR for I-DEASWe are working on the interface to I-DEAS 9 andwe will inform you via our web site (news page)and the ADINA Newsgroup when it is ready.

Figure 1: Thermo-Mechanical Coupled Analysis of DiscBraking System

piston

brake disc

fixed plate

brake pad

brake pad

(a) Schematic

(b) Temperature Distribution at time = 2 seconds

appliedforce

prescribedslip velocity

prescribedslip velocity

ADINA System Newsletter, December 2001 Page 2

Improved Contact Capabilities

A new feature in ADINA 7.6 is the ability to modelcontact slip, i.e. a tangential (slip) velocity can beprescribed between contacting surfaces. This newfeature has several practical applications, includingthe thermo-mechanical coupled analysis of a discbraking system.

In Figure 1(a), we show the schematic of a discbraking system where the heat generation causedby friction between the rotating disc and the pistonand plate is to be analyzed. In this simulation, therotating disc is prescribed to slow from 300 to 0rpm in 5 seconds. The analysis is performed usinga simple 2-D axisymmetric model with the newcontact slip feature. Figure 1(b) shows the solutionof the temperature distribution on the brake com-ponents at the time of 2 seconds.

In ADINA 7.6, the contact algorithm is significantlyimproved, especially with respect to problemswhere the normal vector between the contactingsurfaces frequently changes in direction during theanalysis. This phenomena often occurs in contactbetween flexible surfaces as in the analysis of arubber seal shown in Figure 2.

Initially, as shown in Figure 2(a), there is onlycontact between the rubber ring and the rigidsurfaces. As the deformation progresses, self-contact occurs with considerable amount of slidingbetween the surfaces of the flexible rubber ring.

First, we compare the static analysis solutionbetween ADINA 7.5 and ADINA 7.6. The maximumdeformation that can be solved is significantlygreater in ADINA 7.6 (Figure 2(b)) than in ADINA 7.5(Figure 2(c)). The automatic time-stepping (ATS)method is used in both cases.

When response smoothing (see notes on page 4)is used to overcome convergence difficulties, theproblem can be solved up to the deformed configu-ration shown in Figure 2(d) for both ADINA 7.5 andADINA 7.6. However, the solution time in ADINA 7.6is much less than in ADINA 7.5.

We observe from this rubber seal example that theFigure 2: Analysis of Rubber Seal

robustness and efficiency of the contact algorithmimplementation in ADINA 7.6 are significantlyimproved.

Another new contact analysis feature in ADINA 7.6is the user-supplied friction law option, where auser�s own friction law can be implemented.

(a) Initial Configuration

(d) With Response Smoothing - ADINA 7.5 and ADINA 7.6

(b) Static Analysis - ADINA 7.6

(c) Static Analysis - ADINA 7.5

PrescribedDisplacements

A more robust contact algorithmin ADINA 7.6 allows solution toproceed much further than inADINA 7.5

Solution Times:

ADINA 7.6 : ~ 11 seconds

ADINA 7.5 : ~ 104 seconds

ADINA System Newsletter, December 2001 Page 3

ADINA System 7.6 Developments

It is our goal to provide our users state-of-the-artcapabilities that are easy to use. We present herean overview of the major developments that we areworking on for ADINA 7.6.

� Online HelpContinue to strengthen the interactive HTML-based help system. More topics will be added.

� Material DefinitionIntroduce a material management dialog box toprovide easy access and view of all materialdefinitions.

Allow users to add a description text to materialdefinitions so that it is easier to identify thedefined materials.

Add material database file that allows users tosave material definitions created in the ADINAUser Interface (AUI). Material definitions stored inthe material database file can then be loaded foruse in other AUI models.

� Progress BarAdd progress bar in pop-up window to indicatethe progress of certain tasks which may take asubstantial amount of time to complete, e.g.mesh generation. A Cancel button in the pop-upwindow allows the user to terminate the taskbefore it is completed.

� Automatic Brick MeshingImprovements to our automatic brick meshingcapability with respect to element distributionand speed.

� Display ProcessingVarious improvements such as OpenGL onLinux, improved geometry zone definitions,plotting only selected applied loads, and partialloading of the porthole file for selected timesteps.

� ADINA-M for 64-bit VersionImplement the ADINA Modeler (ADINA-M) for the64-bit version of the ADINA User Interface (AUI)on certain Unix platforms.

� Rubber Material ModelsExtend the existing Ogden and Mooney-Rivlinmodels to allow viscoelastic effects and add newrubber material models. While the other rubbermaterial models are incompressible, a hyper-foam polymer model that is highly compressibleis also added.

� Metal FormingImplement modeling of drawbeads for metalforming analysis. Add adaptive mesh refinementcapability.

� Potential-based Fluid ElementSimplify the modeling of problems involvingpotential-based fluid elements. Some currentlimitations are removed. For example, infiniteelements can be used with the ADINA Modeler(ADINA-M) and large fluid velocities are allowedin the analysis.

� New Shell Element CapabilitiesImplement the MITC-9 and MITC-16 shell ele-ments for large strain analysis. In general, theseelements give more accurate results, but are notas efficient as the MITC-4 elements.

� Rebar ModelingAdd capability to construct rebar elementsautomatically from geometry lines passingthrough 2-D and 3-D solid elements at arbitrarylocations.

� New Navier-Stokes Fluid ElementsNew 4-node quadrilateral 2-D elements and 8-node hexahedral 3-D elements are added forfluid flow analysis. These elements producemore accurate results, especially when veryslender elements are used in the model, asencountered in the modeling of long channels.

� Phase ChangeImprove capabilities of phase change analysis influid flow simulations. Arbitrary phase changeboundaries which propagate depending on thetemperature distribution in the fluid are solved.Phase changes between liquid and vapor re-gions can be analyzed.

ADINA R & D , Inc.71 Elton Avenue

Watertown, MA 02472Telephone: (617)-926-5199

Fax: (617)-926-0238Email: support@adina.com

ADINA is a registered trademark of K. J. Bathe

For additional information about ADINA please visit us at www.adina.com

FOCUSED ON EXCELLENCE

ADINA System Newsletter, December 2001 Page 4

ADINA System 7.6 Developments (cont�d)

� Joule HeatingAdd Joule heating (heating caused by resistanceto current flow) capability in fluid flow analysis.Applications include the analysis of thermalablation (damage) of tissues in the bio-medicalfield.

� Linux VersionImplement the 64-bit version with parallel pro-cessing for the Linux platform.

� Automatic Memory AllocationAutomatically calculate the amount of memoryrequired by the solver programs for matrixstorage and solution.

We will provide further details on some of theexciting developments in the upcoming issues ofthe Newsletter and also through the ADINANewsgroup. However, you are most welcome tocontact us at any time for more information on anyparticular development item that is of interest toyou.

Notes on Response Smoothing

Response smoothing is an option that can beselected with the automatic time-stepping (ATS)method for static analysis problems.

It is a special technique developed to overcomeconvergence difficulties in collapse, post-collapse,and contact problems. In essence, responsesmoothing includes dynamic effects to solve a

static problem. However, once the solution hasbeen obtained, the dynamic effects are no longerpresent.

Note that you must specify density values for yourmaterial properties for the response smoothingoption to be effective.

Did you know that you can find this information inthe AUI online help? To locate this information, lookunder Index > Analysis Control > Analysis Type >Automatic Time Stepping.

Windows XP

We are glad to let you know that our tests showthat the ADINA System installs and works withoutproblems with respect to the new Windows XPoperating system.

Second M.I.T. Conference on ComputationalFluid and Solid Mechanics, June 17 - 20, 2003

Please mark your calendars for the above Confer-ence which will be held in the same spirit as theFirst Conference on the M.I.T. campus.

The mission of the M.I.T. Conference:�To bring together Industry and Academia, andTo nurture the next generation in computationalmechanics.�

You can find more information on the Conferenceat http://www.secondmitconference.org.