Effects Of The Stiffness Of Load Spreaders On The Performance Of Wood Shear Walls

"Light-frame wood structures"has been added in Code for Design of Timber Structures GB 50005-2003, however the major contents were obtained from the test results and codes of North America. Light-frame wood structures are still on the primary stage that the related works have not been studied systemically. Shear walls are commonly used as the primary component of the lateral load resisting system. The research on the performance of lateral load resistance is a key problem in Light-frame wood structures. The purposes of the wood-frame shear wall tests are promoting the application of light wood-frame structures in China and providing scientific background for the revision of Chinese wood design codes.Nails are the most common fastenings used in wood construction. So the performances of sheathing-to-lumber connections directly influenced the lateral resistance capacity of shear walls and the finite element analytical model of wood shear walls is based on the nail joints models moreover model parameters of nail joints are most fitted to the test dates, that will be of great importance to wholly analyze the shear walls and house.Test research of the nail joints on light wood structure is introduced in this paper,2 groups of perpendicular-to-grain and 2 groups of parallel-to-grain nail joints specimens were tested using two different standards of nails, among each group there are 10 specimens and a modified model suitable to domestic nails in two directions were established.The model provides essential dates on the performance of sheathing-to-lumber connections,that can be integrated into the finite element software to analyze wood frame construction.In shear wall tests, the stiffness of load spreader has a direct impact on the failure mode and lateral resistance of wood frame shear walls, and it is worse when hold-downs don't put at the ends of the walls and openings.A new loading setup is used to conduct monotonic and cyclic tests for three full size wood shear walls, load-displacement curves, hysteresis property,shear strength, ultimate displacement, lateral displacement stiffness, energy dissipation, stud lift and bolts stress were studied.The test results were compared with the same configures using articulated and whole load spreaders.At the last part of this paper, ANASYS software is used in the shear walls modeling to verified the behavior of wood shear walls used a new setup recommend is more true.