Constraining delamination of CFRP by beam corrugation

• Published in: Engineering structures 2020-03, Vol.207, p.110237, Article 110237
• Main Authors: Kramár, Samuel, Brabec, Martin, Pařil, Petr, Rousek, Radim, Král, Pavel
• Format: Article
• Language: English
• Subjects: Bending; Carbon fiber reinforced plastics; Carbon fibres; Cyclic loads; Delamination; Dimensional changes; Enlargement; Fiber reinforced polymers; Mechanical properties; Mechanical testing; Polymers; Stiffness; Timber; Vacuum infusion
• ISSN: 0141-0296; 1873-7323
• DOI: 10.1016/j.engstruct.2020.110237

•CFRP was fabricated by the VARTM process directly on the corrugated timber beam.•Corrugated CFRP enhances local bending stiffness.•The corrugation of surface enlarges contact area and higher load for delamination is necessary.•Delamination of CFRP during bending load and fluctuating exposure conditions was constrained. The reinforcement of timber and concrete load bearing beams is increasingly utilized. The most promising effect can be achieved by CFRP (carbon fibre reinforced polymer). However, the difference in mechanical properties of the materials used may be so vast that the two components slip from each other at high stresses. This study deals with the delamination of CFRP from a beam. Design of corrugated reinforced surface is presented. It is based on area enlargement, which leads to a higher applied force needed for CFRP delamination during 4-point bending. Moreover, the corrugated shape comes to synergy with the timber beam which deforms during the flexural load and cyclic humidity. Corrugated CFRP is able to adapt to transverse dimensional changes and vice-versa increases the bending stiffness in the longitudinal direction. All in all, the corrugated shape of CFRP constrains the delamination and seems to be applicable for long-term reinforcement.