1 INTRODUCTION In the last few years the development of glass industry and technology has promoted an increas- ing use of glass, especially for load bearing purposes. At the same time, the major limitations at- tributed to glass (its relatively low tensile strength and brittle behaviour) are being overcome by several different approaches, such as (i) the introduction of new materials that improve the structural behaviour of glass (e.g., the use of stiffer and high performance interlayers in laminat- ed glass sheets), (ii) the use of new methods for connecting glass to other materials, thus provid- ing a better distribution of stresses (e.g., the development of adhesive connections), and (iii) new methods to improve the post-fracture behaviour, such as the development of composite glass beams where glass is carefully assembled to different materials (e.g., wood, stainless steel, concrete or GFRP). Within the latter approach, in the last few years the authors have been developing a compo- site system made of annealed glass panes and glass fibre reinforced polymer (GFRP) pultruded laminates (Correia et al. 2011, Valarinho et al. 2013). The underlying principle of this compo- site system, similar to that of reinforced concrete, relies on the stress transfer between the glass pane and the strengthening material when the tensile strength of glass is attained, thus ensuring post-fracture residual strength and deformation capacity. The research has also been supported by the development of numerical models that allow the simulation of the post-fracture behav- iour of this kind of solution. For now the numerical models were able to reproduce with high accuracy the post-fracture behaviour of beams bonded with adhesives that provide a high level of interaction at bonded interfaces, allowing the assumption of complete interaction between the two materials (Valarinho et al. 2012). This is related with the fact that there is lack of infor- mation on the literature about the mechanical characteristics of adhesively bonded connections between glass and GFRP, namely comprising different types of adhesives. Challenging Glass 4 & COST Action TU0905 Final Conference – Louter, Bos, Belis & Lebet (Eds) © 2014 Taylor & Francis Group, London, ISBN 978-1-138-00164-0 Experimental and numerical study on GFRP-glass adhesively bonded joints L. Valarinho, J.R. Correia, F.A. Branco Instituto Superior Técnico/ICIST, Universidade de Lisboa J. Sena-Cruz School of Engineering/ISISE, University of Minho ABSTRACT: This paper presents experimental and numerical investigations on adhesively bonded double lap joints composed of glass and GFRP pultruded profiles. The experimental programme comprised the study of the effects of using three different adhesives (with varying stiffness) on the bond behaviour of the joints in terms of stiffness, strength, ultimate displace- ment and axial strain development along the GFRP-adhesive interface. In the numerical study, 2D finite element models of the joints were developed in order to simulate the bond behaviour observed in the experiments. Interface elements with either linear or non-linear bond-slip consti- tutive relations were used to simulate the adhesive layers and their shear properties. The numer- ical models were validated by comparing experimental and numerical load vs. relative dis- placement curves and their accuracy was further verified through comparison of the load vs. axial strain distributions along the interfaces.