Investigation of load transfer between the fiber and the matrix in pull-out tests with fibers having different diameters

• Published in: Journal of adhesion science and technology Vol. 15; no. 2; pp. 205 - 222
• Main Authors: Zhandarov, S., Pisanova, E., Mäder, E., Nairn, J. A.
• Format: Journal Article
• Language: English
• Published: Leiden Taylor & Francis Group 01.01.2001; Brill
• Subjects: Applied sciences; Composites; CRITICAL ENERGY RELEASE RATE; Exact sciences and technology; Forms of application and semi-finished materials; LOAD TRANSFER; Polymer industry, paints, wood; PULL-OUT TEST; SHEAR-LAG PARAMETER; Technology of polymers; ULTIMATE INTERFACIAL SHEAR STRENGTH; Propylene polymer; Fiber reinforced material; Mechanical properties; Experimental study; Functional polymer; Composite material; Polymer filler interaction; Amide 6 polymer; Pull out test; Interface properties; Size effect; Amide 66 polymer; Glass fiber; Charge transfer
• ISSN: 0169-4243; 1568-5616
• DOI: 10.1163/156856101743418

Single-fiber pull-out tests were used for investigation of the interfacial bond strength or toughness and load transfer between polymeric matrices and glass fibers having different diameters. The interfacial bond strength was well characterized by an ultimate interfacial shear strength (τ ult ) whose values were nearly independent of the fiber diameter. The same experiments were also analyzed by fracture mechanics methods to determine the interfacial toughness (G ic ). The critical energy release rate (G ic ) was a good material property for constant fiber diameter, but G ic for initiation of debonding typically became smaller as the fiber diameter became larger. It was also possible to measure an effective shear-lag parameter, β, characterizing the load transfer efficiency between the fiber and the matrix. β decreased considerably with the fiber radius; this decrease scaled roughly as expected from elasticity theory. The measured results for β were used to calculate the radius of matrix material surrounding the fiber that was significantly affected by the presence of the fiber. The ratio of this radius to the fiber radius (R m /r f ) was a function of the fiber diameter.