Modelagem em elementos finitos de paredes de cisalhamento do sistema Light-Steel-Framing revestidas por placas de OSB

Abstract

This work describes a numerical study of Light Steel Framing (LSF) shear walls with OSB panels. The objective is to evaluate the structural contribution of these panels in the system. The main object of lateral resistance of LSF structures is the shear wall, thus being the focus of this work. The research evaluates the use of OSB panels in the stiffening of the walls, which makes the panels responsible for transferring lateral forces to the foundation, avoiding excessive lateral displacements in the building. The numerical study using the Finite Element Method (FEM) was based on the bolted connections between cold-formed steel profiles and OSB panels, including at these points, nonlinear behaviors experimentally determined by Datchoua (2018) and previously verified and numerically validated in this work. Subsequently, a numerical validation of a shear wall with an OSB panel, tested by Faria (2023) was carried out, and then a parametric study was developed based on the validated model, to evaluate the following variations in the wall: the thickness of the cold-formed steel profiles, the thickness of OSB panels, number of OSB panels and spacing of connecting screws between steel profiles and OSB panels. The numerical simulation procedure conducted achieved results similar to the experimental results, which indicates high-quality calibration of the numerical models. The parametric analysis entailed in interesting results regarding the lateral strength of the shear walls. The use of greater thickness of cold-formed profiles resulted in a force versus displacement behavior with higher force values, but lower ductility factor and elastic stiffness. The use of greater thickness of the OSB panels generated a greater deformation capacity of the shear wall, causing an increase in elastic stiffness and ductility. In addition, the double closure with OSB plates proved to be efficient with regard to the lateral stiffening of the walls. In the study of shear wall models without OSB panels, it was possible to observe the loss of elastic stiffness. About the connections between the OSB panels and the cold-formed steel profiles, it was possible to perceive that they are parameters of great influence on the lateral behavior of the shear walls. When using larger external and internal spacings, there was a decrease in forces, but a large increase in the ductility factor, without elastic stiffness loss. On the other hand, the use of smaller internal and external spacing resulted in a gain in elastic stiffness. Thus, the results of the parametric study showed the great structural contribution of OSB panels in the lateral stiffness of shear walls, whether due to their thickness, the number of panels used, or the behavior of connections present between OSB panels and the cold-formed steel profiles.