Authors: J. Lopes; L. Reis; D. Stefaniak; M. Freitas; P.P. Camanho
Addresses: IDMEC, Instituto Superior Técnico, Universidade de Lisboa, Av. Rovisco Pais, 1, 1049-001 Lisboa, Portugal ' IDMEC, Instituto Superior Técnico, Universidade de Lisboa, Av. Rovisco Pais, 1, 1049-001 Lisboa, Portugal ' DLR, Institute of Composite Structures and Adaptive Systems, Ottenbecker Damm 12, 21684 Stade, Germany ' IDMEC, Instituto Superior Técnico, Universidade de Lisboa, Av. Rovisco Pais, 1, 1049-001 Lisboa, Portugal ' IDMEC, Pólo FEUP, Rua Dr. Roberto Frias, 4200-465 Porto, Portugal
Abstract: Hybrid CFRP-steel composites are a very promising solution to increase bolt bearing strength in composite aerospace structures. This paper reports the findings on the static and fatigue tests performed in composite specimens made of CFRP and steel foils and compares these results with conventional CFRP specimens. A servo-hydraulic machine was used to perform fatigue tests under load control regime with R = 0.1. Sinusoidal waveforms were adopted to control the load time evolution. Hybrid specimens have a considerable higher static strength than conventional CFRP and therefore their stress levels are higher in absolute values than conventional CFRP specimens. Manufacturing and quality control issues are also addressed. Conventional manufacturing techniques and current quality control techniques can be successfully applied to hybrid CFRP-steel composites.
Keywords: austenitic stainless steel; bearing strength; aerospace composites; fatigue; stress; CFRP; carbon fibre reinforced polymer; aerospace structures; bolted joints; bolts; quality control; composite manufacturing.
International Journal of Automotive Composites, 2016 Vol.2 No.2, pp.139 - 154
Received: 02 Feb 2016
Accepted: 28 Sep 2016
Published online: 06 Feb 2017 *