University of Warsaw
The key parameters needed for fracture analysis are energy release rates. They are usually measured in quasi-static conditions with a standardised low loading rate. However, in many analyses employing interlaminar fracture, such as impact behaviour, fracture propagation is much faster than in the quasi-static conditions. Therefore, in the present study energy release rates have been measured experimentally for GLARE material with three different crosshead speeds (1mm/min, 100mm/min, 5000mm/min) resulting in different fracture propagation speeds ranging from quasi-static to quasi-dynamic. The study focuses on one type of GLARE consisting of 3 plies of UD glass-epoxy composite: external in 0o and middle in 90o direction, embedded between aluminium alloy sheets. The energy release rates for fracture mode I, GcI, were measured using Double Cantilever Beam (DCB) specimens and the energy release rates for fracture mode II, GcII, were measured using End-Notched Flexure (ENF) specimens. The resulting energy release rates were used in the analyses of flat specimens made of the same material subjected to three-point bending tests with different load rates. The results of the analyses were compared with the experimental results: force-displacement curves and modes of failure of the specimens. The analyses allowed drawing conclusions on the influence of loading rate on the energy release rates and the modes of failure of specimens subjected to 3-point bending. These conclusions constitute guidelines for selecting loading rates for measuring energy release rates in the simulation of the impact behaviour of GLARE material.
Abstract
Erwerben Sie einen Zugang, um dieses Dokument anzusehen.
© 2026