Failure behavior and deflection performance of wood I-joists with web holes

This thesis project studied the failure load and deflection behaviours of wood I-joists with web holes. It mainly focused on how web holes affect the strength and deflection of a wood I-joist. Two mechanics-based models (strength model and deflection model) were developed to predict the failure load and the deformation of an I-joist with a web hole for design use. Material property and full-size I-joist tests were conducted to verify the models.;In the strength model, according to the beam theory and Vierendeel analysis, the total stress around a web hole arises from two sources, the primary bending and shear stresses generated by the external load on the span, and the secondary bending stresses caused by the internal shear force applied across the web hole, which is known as the Vierendeel effect. The test data showed that this model provides good estimates of failure load for wood I-joist with a web hole. In the deflection model, the deflection across the imperforated section of an I-joist is divided into two parts: (i) the deflection due to bending, (ii) the deflection due to shear. The relevant test data obtained showed that this model can provide a reasonable prediction of deformation across a web hole in a wood I-joist.