1 Risø National Laboratory for Sustainable Energy, Technical University of Denmark2 Department of Wind Energy, Technical University of Denmark3 unknown
Medium-size specimens (<2 m in length), consisting of two glass-fibre beams bonded together by an adhesive layer were tested in four point bending to determine their load carrying capacity. Specimens having different thickness were tested. Except for onespecimen, the cracking occurred as cracking along the adhesive layer; initially cracking occurred along the adhesive/laminate interface, but after some crack extension the cracking took place inside the laminate (for one specimen the later part of thecracking occurred unstably along the adhesive/ laminate interface). Crack bridging by fibres was observed. The measured applied moment at steady-state crack growth was compared with predictions based on independent mixed mode fracture resistancemeasurements made on small laboratory specimens. The predicted and measured strength values of the medium-size specimens were found to be in good agreement with each other. Thus, the scaling from small specimens to medium-size specimens was successfullyachieved.