No.8（2013）19.Fabrication and evaluation of CFRP loop-springs

Yasuhiro Nishikawa, Hiroyasu Sano, Satoshi Kobune

  In this study, unidirectional carbon/epoxy composite (CFRP) loop-springs were fabricated using a mass-production method. The loop-springs consists of circular arc sections, straight-line sections and flat attachment surfaces. Two types of CFRP loopsprings with different straight line section lengths were tested to evaluate the spring constant, ultimate load and fatigue lives. CFRP loop-springs were approximately 9 times lighter than metallic coil springs with the same spring constant. A comparison of the experimental spring constant with the calculated spring constant, based on the cantilever model, showed good agreement. CFRP loop springs had fatigue lives beyond two million cycles under a maximum cyclic load of approximately 60% of the ultimate load.

Keywords
CFRP, Loop, Spring, Spring constant, Cantilever model, Fatigue

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