Effect of cracks on the load-carrying capacity of glulam

Abstract

Engineered wood products (EWPs) may be prone to cracking though the impact of these cracks varies depending on the specific product. The impact of existing cracks on the structural behaviour of different EWPs is potentially detrimental in practical applications but has not been sufficiently studied. To meet the challenge, the primary objective of this study is to investigate the influence of crack length and location on the load-bearing capacity of glulam. Over 50 glulam beams with 10 different initial cracks were tested. The examined cracks were artificially induced delaminations of different lengths located in the middle of the beam's cross-section. Based on the findings, the length of the crack has an impact on the shear strength of the beam, but less than expected in the light of a simplified structural analysis that incorporates the crack into the effective width of the cross-section. Additionally, the crack length importance is connected to the stress state along the crack. The practical use of this study lies in improving the structural reliability of glulam by understanding how crack parameters affect the loadbearing capacity. As the main conclusions of the study, practical guidelines for the assessment of the load-bearing capacity of glulam with existing cracks were given.