CompositesWorld
Issue link: https://cw.epubxp.com/i/697353
JULY 2016 30 CompositesWorld CFRP Design Tis has an impact on design charts, such as the carpet plots developed by the early pioneers in the 1960s. Tese have had limited utility in the compos- ites industry. Te reason why is that the laminates shown in a carpet plot, such as [0° 5 /±45° 2 /90°] and [0°/±45°/90°], are discrete; that is, there is no discernable thread or connection between any two laminates. But trace could change that. In the sample carpet plot (Fig. 3, on p. 29), with the percebtage of (±45°) plotted on the horizontal axis and the fractional stifness on the vertical axis, fve materials are indicated, with their traces listed on the top line. You get all you need in the laminate stifness. For each material, the diference is merely in the ratio of their traces. Tat makes the carpet plot for every laminate universal: We can make one carpet plot for all CFRP materials, not one for each material. Trace is not a passing fad. It shows us that laminates and CFRP materials are interrelated, mathematically, and there- fore, those who understand and accept those relationships and learn to use them to their advantage can make part design, development and manufacture easier and faster and, therefore, less expensive and more proftable. Beyond that, however, I also contend that with trace, better laminates can be selected, leading not only to parts with less weight and greater strength and toughness, but less challenging stacking sequences. Today's sometimes "bricky" and "patchy" designs with 8- or 10-ply families (with dozens of members) could become a thing of the past, traded in for more homogenous laminate designs that feature thin sub-laminates of a few plies. Trace ofers the opportunity to vastly simplify simulation with homogenized laminates instead of the highly heteroge- neous designs. Sufce it to say at this point, trace is the quarterback or star pitcher of a new team. It is that important. It opens a totally new vista in composite design, testing and manufacturing. Don't leave home without it. ABOUT THE AUTHOR Stephen W. Tsai is professor research emeritus in the Depart- ment of Aeronautics & Astronautics at Stanford University. He holds a BE and D.Eng from Yale University. Tsai is a lifetime member of the National Academy of Engineering and the International Committee on Composite Materials (ICCM), a life fellow of the American Society of Mechanical Engineers (ASME) and fellow of the Society for the Advancement of Material and Process Engineering (SAMPE). He has trained thousands of engineers in composite materials and is a co-author, with the late Edward M. Wu, of the Tsai-Wu failure criterion for anisotropic composites. When you partner with Composites One, you'll work with a dedicated team of PEOPLE, from Advanced Composites sales specialists and technical market managers who understand the challenges you face, to regional customer service reps and local support teams at over 35 North American distribution centers, including those with onsite prepreg freezer storage. You'll gain access to the industry's broadest range of high performance PRODUCTS, learn about innovative PROCESSES that can help your business grow, and get the PERFORMANCE you should expect from the nation's leading advanced composites distributor. That's the power of Partnership. The Power of One – Composites One. 800.621.8003 | www.compositesone.com | www.b2bcomposites.com Find out more at Compositesone.com/prepregfreezer. Get the Power of Partnership. Composites One Choose from the broadest, deepest line of high performance products from the industry's top suppliers. North Region South Region West Region Eastern Canada Distribution Centers (DCs) DCs with Prepreg Freezer Storage Additional Stock Points North America's most expansive advanced composites materials distribution network including prepreg freezer storage at several locations. Go to compositesone. com/prepregfreezer. Read more online about trace in the following: Dr. Tsai introduces trace in "Overnight design allowables? An invariant-based method for accelerating aerospace certification testing" | short.compositesworld.com/TsaiCerTst "CompoSIDE, Tsai seek collaborators to assess trace-based scaling theory" | short.compositesworld.com/UMINTgH5 "CompoSIDE and Trace: Game-changer for development of composite parts" | short.compositesworld.com/CompoTrace