Evaluation of Flexural properties of the U-shape Composite Spring

CFRP (carbon fiber reinforced plastics) which provides high specific strength/stiffness is adopted in assistive products such as orthosis for relieving the physical burden of patients. The orthosis needs the flexible configuration of articulations like walking of normal subjects. Since the CFRP autoclave method is suitable for molding complex shape parts, a structural component containing a partially curved region such as U-shape can be integrally molded by the method. Flexibility characteristics are added to a structural component without an increase in the number of parts. In this study, the flexibility of CFRP was evaluated for embedded light and durable springs into orthosis. First, three-point bending tests of the flat laminate were performed to assess the advantage of CFRP used as spring materials. Second, the flexural properties and fracture mechanism of a U-shape spring were investigated in comparison with the results of the flat laminate. The study confirmed the advantage of CFRP employed as a spring material. (C) 2018 The Authors. Published by Elsevier B.V. Peer-review under responsibility of the scientific committee of the 46th SME North American Manufacturing Research Conference.