CompositesWorld
Issue link: https://cw.epubxp.com/i/841219
TRENDS JULY 2017 16 CompositesWorld not allow for expensively engineered structures. In addi- tion, the composite stinger is a drop-in replacement for its predecessor. Because the carbon fiber stinger works as a component retrofit compatible with existing cranes, RIBA's engineers exploited all the available design space, maximizing the moment of inertia and the geometric properties of the stinger. The result is a hybrid structure where steel and composite match to take advantage of the specific proper- ties of each material. The junction between steel and composite relies on bonding and bolts, which allow an efficient solution. Andrea Bedeschi, general manager at Riba, says the composite stinger is hand-laid, using carbon fiber prepreg and autoclave cure. The carbon fiber, standard-modulus 12K and 24K tow, is supplied by Mitsubishi and Toho Tenax. The resin is a toughened epoxy. Riba performed NDT eval- uation of the stinger; physical load, stability and structural performance testing was done by Manitowoc. The composite stinger is 35% lighter than its steel prede- cessor and, says Munuswamy, increases payload capacity 12-15% more than the steel version in some specific boom configurations. The composite stinger also is more expen- sive than its steel predecessor, but Munuswamy says this is more than compensated for by increased jobsite efficiency and transportability. Will Manitowoc expand carbon fiber use to other crane components? "This [the stinger] is leading us in that direc- tion," Munuswamy says. "The stinger was the first step." (continued from p. 15) +1 (775) 827-6568 • www.abaris.com USA LATIN AMERICA EUROPE • EXPLORE Our Training Programs • DISCOVER Best Industry Practices • GAIN Applicable Lifetime Skills High Performance Tooling for the Composites Industry • Steel • Invar • NVD Nickel • Aluminum • Precision Machining composites@webermfg.ca webermfg.ca