CompositesWorld
Issue link: https://cw.epubxp.com/i/576646
OCTOBER 2015 90 CompositesWorld PLANT TOUR that have vastly diferent constituent properties is one of the most challenging issues when engineering composite structures," explains Cassin. "Our strength is understanding multi-phase materials. For example: fber-to-matrix interfaces, commingled fbers and binding systems." MSC has developed a deep knowl- edge of organic polymers and metals, the latter not only as a matrix for composites but also as a bonding substrate. "Te Achilles heel of composites is attachment to non-composites," he points out. "We have specialty software that models the mechanics of joining and helps understand how to test and inspect these joints." MSC proved the durability of its joint design via full-scale tests, using a reconfgurable 445-kN modular test frame that simulates static and fatigue responses of full-scale ship bulkheads or girders. Transitioning R&D; into commercial products Trough this program, MSC developed a much better under- standing of how to tailor a composite's sound-transmission properties. It also recognized an opportunity to optimize materials not for sound transmission, but for sound disruption. After signif- cant development, MSC launched COUNTERVAIL, a composite material that can be integrated into a structure to signifcantly reduce vibration without adding parasitic weight. Appropriately named (countervail means to act against with equal force), its char- acteristics, including drapability, stifness and damping coefcient, can be tailored to the application. COUNTERVAIL comprises a lightweight viscoelastic combined with a patented fber preform, and can be made with any fber or combination of fbers, including carbon, glass or aramid. Te preform features a fber pattern that maximizes the vibrational energy dissipation provided by the visco- elastic component. One of MSC's frst applications for COUNTERVAIL was in high- performance skis, with the goal to enhance the skier's speed and control. "You only ski fast when the ski is in contact with the snow," explains Cassin, "because the edge is actually melting the snow. If the ski chatters, it loses speed." MSC built a model to predict and optimize the performance of COUNTERVAIL in a ski. Te material has been used in boutique skis, such as Wagner and Romp, and feld trials are in progress at a major ski manufacturer. Bianchi (Milan, Italy), a bicycle manufacturer often associated with Tour de France winners, saw MSC's demonstration of COUN- TERVAIL in skis and began collaborating with MSC to apply it in a bike frame. MSC's computer modeling showed a potentially signifcant performance diference vs. Bianchi's standard carbon fber composite frame. Bianchi then adopted COUNTERVAIL in its 2014 Infnito CV model, which was ridden by cyclist Lars Boom to win Stage 5 of the 2014 Tour de France, a stage known for its bike frame-chattering cobblestones. "COUNTERVAIL does not interrupt the shock of hitting a cobblestone," Cassin explains, "but that impulse excites the bike frame structure to resonate at a natural frequency." He gives an example of striking a bell: "Te ring is still there, but with COUN- TERVAIL, it will not be there for very long. Similarly, you will still feel the impulse from going over a bump, but you won't be subjected to the vibratory envelope." Cassin adds that in addition to the vibrational frequencies you can feel, there are hundreds that Weaving fabrics in three dimensions Standard and specially modifed weaving looms produce a range of customized fabrics, including 3D weaves for ballistics and blast-resistance applications. Source | Materials Sciences Corp. The secret is in the software MSC has developed and licensed both standalone and third-party commercial software modules for material modeling and for predicting structural response, damage progression, and impact behavior of composites. Examples include TexLink (left) and ABAQUS: UMATs for damage progression prediction (right). Source | Materials Sciences Corp.