PurposeThe sheathing panels of traditional light wood frame shear walls mainly use oriented strand board (OSB) panels, and the damage of the traditional walls is mainly caused by the tear failure at the bottom corner of the OSB panel. In order to improve the lateral performance of the traditional light wood frame shear wall, a new type of end narrow panels reinforced light wood frame shear wall is proposed.Design/methodology/approachThe monotonic loading tests and finite element analysis of nine groups of walls, with different types of end narrow panel, types of fasteners used on the end narrow panels and the end narrow panels edge fastener spacing, are carried out. The effects of different characters on lateral performance of light wood frame shear walls are reported and discussed.FindingsThe failure modes of the wall reinforced by parallel strand bamboo narrow panels with 150 mm edge nails spacing are similar to the traditional wall. Conversely, the failure modes of other groups of walls reinforced by end narrow panels are the tears of the bottom narrow panel or the bottom beam. The end narrow panel reinforced light wood frame shear wall can make full use of the material property of sheathing panels. Compared with the lateral performance of traditional walls, the new-type end narrow panels reinforced walls have better lateral performance.Originality/valueA new type of end narrow panels reinforced light wood frame shear wall is proposed, which can enhance the lateral performance of the traditional light wood frame shear wall. The new-type walls have advantages of convenient operation, manufacture cost saving and important value of engineering application.

Due to the creep characteristic of wooden materials, long-term loading exerts great influence on the strength and stiffness of wooden crafts. Based on the experiment of long-term loading, this paper conducted comparative experiment on beams that were not long-term loaded, beams that were long-term loaded, and long-term loaded beams whose deformation was adjusted to the original size at the beginning of long-term loading through pre-stressing device. Results show that: pre-stress control can saliently improve the failure modes of beams; long-term loading decreased the ultimate load by13%~39.34%, while pre-stress control increased the ultimate load by 12.23%~74.03%; long-term loading had little influence on beams stiffness, but decreased their deformation capacity by 39.47%~55.76%. Pre-stress control had little influence on beams deformation capacity, but remarkably improved their strength.

This paper describes experimental and numerical investigations on a new type of strengthened light-wood-framed (LWF) shear wall (SW) that has parallel strand bamboo (PSB) panels at each end. The experiments are divided into two parts: (1) monotonic loading tests of panel-to-frame joints representing different positions along the wall; (2) monotonic loading tests of a group of traditional full-scale SWs and two groups of strengthened walls with nailed or screwed PSB panels. The failure modes, load–displacement curves, ultimate bearing capacity, elastic stiffness, and dissipation are analyzed, and the mechanical properties of panel-to-frame joints and the lateral performance of SWs are discussed. Moreover, nonlinear finite-element analysis shows that the numerical results are in good agreement with the test results. Our findings suggest that using LWF SWs strengthened with nailed PSB panels effectively improves the failure mode and the ductility, stiffness, and dissipation of traditional walls. Using sheathing screws on the PSB panels increases the lateral bearing capacity and the dissipation of the walls, but decreases their ductility ratio. Setting end PSB panels improves the overturning resistance capacity by restricting the uplift of studs. The LWF SWs strengthened with end PSB panels are found to meet the design requirements and reduce construction costs.

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The seismic performance of a light wood frame structure is determined by sheathing-to-framing joints. In order to encourage the use of more sustainable materials in structures, the spruce-pine-fir (SPF) panel and the bamboo scrimber (BS) panel were considered as sheathing materials. Monotonic and cyclic tests were conducted on the joints with different parameters to obtain their mechanical properties. Moreover, the design value of the bearing capacity of sheathing-to-framing joints was calculated and compared in accordance with Chinese code (GB50005) and European code (Eurocode 5). Based on the test results and the design codes, the reliability index of the design value of the bearing capacity of joints was calculated using the first-order reliability method (FORM). Results demonstrate that the joints have high bearing capacity and stiffness at initial loading stage when the loading direction is perpendicular to the framing grain. BS panels make better use of the bending strength of fasteners than SPF panels. The screwed joints have lower strength and stiffness degradation than nailed joints, but the nailed joints show better ductile and dissipation than screwed joints. In addition, the reliability indexes of design bearing capacity calculated by the Chinese code of joints under monotonic load are conservative, but those of joints under cyclic load are unconservative. Therefore, in order to ensure the safety and economy of design, a modification factor for the GB50005 design method of joints is proposed to meet the target reliability index.