UBC Theses and Dissertations
Performance of strand-based wood composite post-and-beam shear wall system Lim, Hyungsuk
This dissertation proposes a strand-based wood composite product to be utilized as the vertical members of post-and-beam (P&B) shear walls. Since the shear wall performance is largely governed by connection systems holding the wall components together, the research focuses on the structural behaviour of two key connection types: nail and hold-down connections. The experimental studies were designed to evaluate the effects of orthogonal properties, such as vertical density profile of the strand-based product, on the connection performance. Static load tests were conducted following ASTM standards and Japanese HOWTEC connection performance guidelines. The test results showed that the connections with fasteners mounted on the face-side of the composite product outperform the ones with fasteners mounted on the product’s edge-side. Subsequently, full-scale shear wall tests were conducted on three P&B wall types to study the effect of the fastener driving direction on the wall performance. The test results confirmed that the shear walls with face-driven nails outperforms the ones with edge-driven nails in terms of load carrying capacity. A detailed mechanics-based finite-element connection model RHYST was also developed to predict the load-displacement relationship of a nail connection. It was developed based on an existing connection model HYST which idealizes a dowel-type connector driven into a wood medium as an elasto-plastic beam embedded in a nonlinear foundation that only acts in compression. RHYST assumes that the lateral response of the wood medium does not decrease at any compressive displacement. The presented model takes into account the contribution of the fastener’s vertical displacements on the response of the foundation. The simulation results of RHYST agreed well with the reversed-cyclic nail connection test results in terms of load carrying capacity and energy dissipation. The model is also able to simulate strength and stiffness degradation between the repeated loading cycles. Moreover, the applicability of RHYST was confirmed by incorporating it as a subroutine in a finite-element shear wall model WALL2D. The simulation results of WALL2D with RHYST showed a good agreement with the wall test results.
Item Citations and Data
Attribution-NonCommercial-NoDerivs 2.5 Canada