CompositesWorld

OCT 2018

CompositesWorld

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9 REFERENCES 1 Composite Materials Handbook - 17 (CMH-17), Volume 1, Section 6.6.3: "Glass Transition Temperature," SAE International, Rev. G, 2012. 2 ASTM D7426-08(2013), "Standard Test Method for Assignment of the DSC Procedure for Determining Tg of a Polymer or an Elastomeric Compound," ASTM International (W. Conshohocken, PA, US), 2013. CompositesWorld.com Glass transition temperature testing temperature for thermosetting PMCs, a somewhat lower temper- ature is typically chosen as the maximum allowable tempera- ture for a particular application. Within the aerospace industry, a material operational limit (MOL) is established by reducing the T g by a prescribed value, typically 28°C / 50°F, below the measured glass transition temperature. Additionally, it is common practice to perform two T g measurements: one without any moisture preconditioning (dry T g ) and a second using speci- mens that have been moisture conditioned (wet T g ). Note that wet T g testing of PMCs is particularly challenging because the specimen tends to lose moisture as it is heated during DMA testing. e use of thicker specimens can help minimize effects of specimen drying during T g testing. After determining the dry and wet T g values for a PMC, and establishing an appropriate MOL, it is common practice to perform a series of mechanical tests at the MOL temperature, particularly with specimens that have been moisture conditioned. e resulting "hot/wet" material properties of PMCs often repre- sent a limiting environmental condition. 3 ASTM E1545-11(2016), "Standard Test Method for Assignment of the Glass Transition Temperature by Thermomechanical Analysis," ASTM International (W. Conshohocken, PA, US), 2016. 4 ASTM D5026-15, "Standard Test Method for Plastics: Dynamic Mechanical Properties: In Tension," ASTM International (W. Conshohocken, PA, US), 2015. 5 ASTM D5024-15, "Standard Test Method for Plastics: Dynamic Mechanical Properties: In Compression," ASTM International (W. Conshohocken, PA, US), 2015. 6 ASTM D5279-13, "Standard Test Method for Plastics: Dynamic Mechanical Properties: In Torsion," ASTM International (W. Conshohocken, PA, US), 2013. 7 ASTM D5023-15, "Standard Test Method for Plastics: Dynamic Mechanical Properties: In Flexure (Three-Point Bending)," ASTM International (W. Conshohocken, PA, US), 2015. 8 ASTM D5418-15, "Standard Test Method for Plastics: Dynamic Mechanical Properties: In Flexure (Dual Cantilever Beam)," ASTM International (W. Conshohocken, PA, US), 2015. 9 ASTM D4065-12, "Standard Practice for Plastics: Dynamic Mechanical Properties: Determination and Report of Procedures," ASTM International (W. Conshohocken, PA, US), 2012. 10 ASTM D7028-07(2015), "Standard Test Method for Glass Transition Temperature (DMA Tg) of Polymer Matrix Composites by Dynamic Mechanical Analysis (DMA)," ASTM International (W. Conshohocken, PA, US), 2015. ABOUT THE AUTHOR Dr. Daniel O. Adams is a professor of mechanical engineering and has been the director for 21 years of the Composite Mechanics Laboratory at the University of Utah and vice president of Wyoming Test Fixtures Inc. (Salt Lake City, UT, US). He holds a BS in mechanical engineering and an MS and Ph.D in engineering mechanics. Adams has a combined 38 years of academic/industry experience in the composite materials field. He has published more than 120 technical papers, is vice-chair of ASTM Committee D30 on Composite Materials and co-chair of the Testing Committee for the Composite Materials Handbook (CMH-17). He regularly provides testing seminars and consulting services to the composites industry. AOC has the formula for your success. You can count on AOC for unparalleled innovation — backed by the best quality and service in our industry. @AOCresins Contact AOC at +01 866.319.8827 or visit us at AOC-Resins.com to learn more. Quality Innovation Service

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