Lateral behavior of wood frame shear walls sheathed with densified plywood under monotonic loading

摘要

Modern construction projects such as high-rise buildings require increasingly lighter and stronger wood frame shear walls. The stress level of the edge zone in the sheathing panel is generally larger than that of the middle zone under lateral loading, and the mechanical properties of wood-based panels are positively related with density. A series of fast-growing poplar plywood with a marginal or overall densification were prepared in this study for use as wood shear wall sheathing panels. The plywood density was controlled to 550, 550 (edge, 650), 550 (edge, 840), and 650 kg.m(-3), then full-scaled walls sheathed with the samples were monotonically loaded and compared against a wall sheathed with 12 mm OSB to determine the effects of densification. The elastic lateral stiffness of the densified plywood sheathing wall with marginal density of 650 and 840 kg.m(-3), relative to 550 kg.m(-3), increased by 39.8% and 47.8% as the ultimate bearing capacity was increased by 15.5% and 37%, which is better than the commonly-used OSB sheathing wall accompanied by slightly lower ductility. The lateral behavior of the plywood sheathing wall appears to increase as density increases. The marginal-densified plywood can substitute for overall densified material as it presents nearly identical lateral behavior when used as a wood shear wall sheathing panel. The wall with marginal density of 840 kg.m(-3) showed the best overall lateral performance in this experiment. Relative error was controlled within 10% using the rheological model proposed by Casagrande to theoretically verify the lateral bearing capacity and lateral displacement of the test wall.