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SVELT into their research and development roadmaps tosupport next generation aircraft and rotorcraft.” In additionto reducing testing, Mr. Schaff identifies gains instructural efficiency. Presently, the design envelope isrestricted and overly conservative due to the inability of theexisting methods to predict key trends in test data. One difficultyto successful transition of SVELT is its incorporationinto a design system. Although SVELT has a userfriendlypreprocessor, the software lacks the simplifiedinput and failure postprocessing routines necessary for executionby design engineers. Evolving SVELT to predictactual damage initiation and evolution represents a significantchallenge, one that may very well stretch the boundsof available technology. This has been the goal of theSVELT program since the very beginning and nothing todate indicates that the objective is not achievable.ConclusionsAs mentioned above, the goal of the SVELT program is todevelop the capability to predict strength and the evolutionof damage. Some work has been done in the area of modelingthe stress fields surrounding discrete damage such astransverse ply cracking or delaminations in simple laminates[13].The challenge for the future is to expand uponthis fundamental work so that damage evolution and jointstrength prediction are the natural output of the analysis.Assuming this can be done, design engineers would then beable to replace their existing and costly methods with a newmethod that predicts strengths based solely on intrinsiccomposite properties. SVELT shows promise as a means ofachieving this objective. Making the jump to this level ofcapability does represent a fundamental challenge.However, the benefits of achieving this capability would beimmense and would have a profound impact on the designof future composite structures.The seven-year effort to develop SVELT has been a complexundertaking and to date has yielded many breakthroughsin the area of mechanical modeling. As a result ofthis initiative, we now have an emerging capability thatshows tremendous promise to allow for far greater insightinto the strength of bolted structures. The benefits fromsuch a refined design tool are many with the most importantbeing the ability to reduce cost and risk on future programs.The development team has not lost sight of theirobjective and the focus has remained constant throughoutthe length of the project. As a result, the research conductedon using B-spline approximations for modeling compositematerials could prove to be a very important advance inthe area of applied mechanical modeling of composite structures.Industry certainly has paid attention to these effortsand the existence of the Alliance itself demonstrates how aformal team of engineers from the government and industrycan form unique partnerships to achieve solutions tocomplex problems.REFERENCES[1] Lekhnitski, S.G., 1968. Anisotropic Plates, Gordonand Breach Science Publishers[2] Pullman, D. and Schaff, J., “Three Dimensional SplineVariational and Finite Element Theory: A Comparison fora Laminate with a Circular Hole,” American Society forComposites, 11th Technical Conference on CompositeMaterials: Structural Design and Analysis Methods,Atlanta, 1996[3] Iarve, E.V., 1996, “Spline Variational ThreeDimensional Stress Analysis of Laminated CompositePlates with Open Holes,” International Journal of Solidsand Structures, Vol. 33, No. 14, pp. 2095-2118[4] Schaff, J.R., Mollenhauer, D.H., and Rose, D.H.,“Experimental Verification of Spline Stress AnalysisMethod for a Structural Composite Laminate Containinga Hole,” Journal of Reinforced Plastics and Composites,Vol. 17, pp. 96-108[5] Pagano, N.J., and Pipes, R.B., “The Influence ofStacking Sequence on Laminate Strength,” Journal ofComposite Materials, January 1971, pp. 50-57[6] Rodini, B.J., and Eisenmann, J.R., “An Analytical andExperimental Investigation of Edge Delamination inComposite Laminates,” Proceedings Fibrous CompositeStructural Design Conference, 1978, pp. 441-458[7] Iarve, E.V., “Asymptotically Exact Stresses in Laminateswith Rigid Fastener,” J. Composite Science andTechnology, in press[8] Iarve, E.V. and Pagano, N.J., 2000, “Singular Full-fieldStresses in Composite Laminates with Open Holes,” Int. J.Solids Structures, accepted[9] Mollenhauer, D.H., 1997, “Interlaminar Deformationat a Hole in Laminated Composites: A Detailed ExperimentalInvestigation Using Moiré Interferometry,” Doctorof Philosophy Dissertation available for download at theVirginia Polytechnic Institute and State University library’sWeb page http://scholar.lib.vt.edu/theses/theses.html[10] Mollenhauer, D.H. and Reifsnider, K.L.,“Interlaminar Deformation Along the Cylindrical Surfaceof a Hole in Laminated Composites - ExperimentalAnalysis by Moiré Interferometry,” CompositesTechnology and Research, in press[11] Iarve, E.V., 1997, “Three-dimensional Stress Analysisin Laminated Composites with Fasteners Based on the B-spline Approximation,” Composites Part A, Vol. 28A, pp.559-571[12] Iarve, E.V. and Whitney, T., “Three-dimensionalStress Analysis in Composite Laminates with ElasticFastener and Washer Clamp-up,” Proceedings, AmericanSociety for Composites Fifteenth Technical Meeting,Dayton OH[13] Iarve, E.V., “Spline Variational Theory for CompositeBolted Joints,” Interim Technical Report WL-TR-97-4016RecentAdvancescontinuedfrompage 78The AMPTIAC Newsletter, Volume 4, Number 1
Mark Your CalendarInternational Conference on HighPerformance Materials in BridgesJul 29-Aug 3, 2000Kona, HIPhone: (212) 591-7836Fax: (212) 591-7441Email: engfnd@aol.comWeb Link: www.eufoundation.orgCorrosion of Aging AircraftAug 14-17, 2000Los Angeles, CAContact: Marcus Hennessy; UCLAPhone: (310) 825-1047Fax: (310) 206-2815Email: mhenness@unex.ucla.eduWeb Link: www.uclaextension.org/shortACerS Functionally Graded MaterialsConference (FGM2000)Sep 10-14, 2000Estes Park, COContact: Customer Service Dept.;The American Ceramic SocietyWesterville, OH 43086-6136 USAPhone: (614) 794-5890Fax: (614) 899-6109Email: customersrvc@acers.orgWeb Link: www.acers.orgMidwest Advanced Materials andProcessing ConferencesSep 12-14, 2000Dearborn, MIPhone: (626) 331-0616 x 610Fax: (626) 332-8929Email: sampereg@aol.comWeb Link: www.sampe.orgNinth International Symposium onSuperalloysSep 17-21, 2000Champion, PAContact: T.M. Pollock; CMUMSE Dept. 33095000 Forbes Ave.Pittsburgh, PA 15213 USAPhone: (412) 268-2973Fax: (412) 268-75964th Conference on Aerospace Materials,Processes & Environmental Technology.(AMPET)Sep 18-Sep 20, 2000Huntsville, ALContact: Jodie Weiner;Native Amer. Srvcs. Inc.Phone: (256) 533-5923Fax: (256) 534-9899Laser Applications in DoDSep 24-Sep 27, 2000State College, PAContact: Cindy Hull;Penn State University, Applied Research LabEmail: ckh4@psu.eduWeb Link:www.arl.psu.edu/dodconference.htmlComposites 2000Sep 27-30, 2000Las Vegas, NVPhone: (703) 525-0511Fax: (703) 525-0743Email: cfa-info@cfa-hq.orgWeb Link: www.cfa-hq.orgACerS Glass & Optical Materials,Fall MeetingOct 1-4, 2000Corning, NYPhone: (614) 794-5890Fax: (614) 899-6109Email: customersrvc@acers.orgWeb Link: www.acers.orgACerS Electronics Division Fall MeetingOct 8-11, 2000Clemson, SCPhone: (614) 794-5890Fax: (614) 899-6109Email: customersrvc@acers.orgWeb Link: www.acers.org16th Anniversay International TitaniumAssociation Conference & ExhibitionOct 8-11, 2000New Orleans, LAPhone: (303) 404-2221Fax: (303) 404-9111Email: info@titanium.orgWeb Link: www.titanium.orgThe 2000 TMS Fall Meeting: PhysicalMetallurgy and MaterialsOct 8-12, 2000St. Louis, MOPhone: (412) 776-9000 x 270Fax: (412) 776-3770Email: csc@tms.orgWeb Link:www.tms.org/meetings/meeting.htmlSAE World Aviation Congress andExpositionOct 9-10, 2000San Diego, CAContact: Anthony Incorvati; SAEWarrendale, PA 15096-0001 USAPhone: 724/772-7191Fax: 724/776-0210Email: incorv@sae.orgWeb Link:www.sae.org/calendar/wac/index.htmMaterials Solutions Conference andExpositionOct 9-12, 2000St. Louis, MOPhone: (440) 338-5151Fax: (440) 338-4634Email: mem-serv@po.asm-intl.orgWeb Link: www.asm-intl.orgSecond International Conference onProcessing Materials for PropertiesNov 5-8, 2000San Francisco, CATMSWarrendale, PA 15086-7528 USAPhone: (412) 776-9000 x 927Fax: (412) 776-3770Email: cms@tms.orgWeb Link: www.tms.org/cms32nd InternationalSAMPE Technical ConferenceNov 5-9, 2000Boston, MAPhone: (626) 331-0616 x 610Fax: (626) 332-8929Email: sampereg@aol.comWeb Link: www.sampe.orgMRS Fall MeetingNov 27-Dec 1, 2000Boston MAPhone: (724) 779-3003Fax: (724) 779-8313The AMPTIAC Newsletter, Volume 4, Number 1 9
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