DIC Strain Field Measurement of FRP Plates with and without Holes

This paper examines the results of material testing of hybrid glass/carbon fiber reinforced polymer (FRP) plates for use in mechanically fastened applications. The small-scale material tests were conducted in three phases: 1) uniaxial tension without holes, 2) uniaxial tension with open holes, and 3) uniaxial tension with bolted connections. In all three phases of testing, Digital Image Correlation (DIC) was used to obtain continuous strain data, showing holistic strain field development through failure. The high-resolution strain data provides detailed information for the design of an efficient hole pattern in Mechanically Fastened-Fiber Reinforced Polymer (MFFRP) plates. The tests presented here are an initial phase of a larger project that aims to employ prestressed MFFRP plates as a repair for deteriorated prestressed hollow-core bridge slabs. Candidate slabs are those that have exposed tendons such that the bridges are typically load posted. It is proposed that the use of a prestressed MFFRP repair will restore lost performance until replacement can be scheduled in a way that is cost effective, rapid, and enables periodic inspection over the lifespan of the short-term repair – prior to scheduled superstructure replacement. The use of prestressed MF-FRP in this application will eliminate the need for an adhesive bond and QA/QC concerns that are often associated with externally bonded FRP