Strength Enhancement of Cold‐Formed Compression Members in Composite with High Strength Linings

Over the last few decades, the use of cold-formed steel studs (plain C or lipped C sections) have gained increasing popularity as primary load bearing wall components in the construction of residential, industrial, and commercial buildings. In more recent times, there has been a growing interest in the development of lightweight prefab modular structures for which cold-formed steel sections are used to frame the walls, floors and roof structural components. Traditionally, the load bearing walls are lined with gypsum plasterboard that will enhance the strength and stiffness capacity of the wall components. However, since plasterboard is not regarded as a structural component, its contribution to the axial load capacity of the wall components are not considered in the design.

Numerous theoretical and experimental studies have been conducted to investigate the influence of various parameters on the axial load capacity and the failure modes of such wall systems. These parameters include but are not limited to the screw spacing, stud section and spacing, type of sheathing, hole of stud web and height of wall stud. While these experimental studies are within our scope of work, they differ slightly from our project, mainly focussing on cold-formed steel wall systems lined with one layer of gypsum plasterboard or oriented standard board on both sides, which are typically used in low-rise cold-formed steel structures.

To date, there has been very limited research conducted to understand the strength contribution of gypsum plasterboard to walls framed with cold-formed steel studs. Finite Element Analysis (FEA) models created and tested in ABAQUS build the foundation of this study and the results obtained are used to understand how the strength capacity of the steel stud wall components are enhanced when lined with traditional gypsum plasterboard. Subsequently, the interaction between the cold-formed steel studs and plasterboard lining in a load bearing wall unit are established. Finally, simple analytical tools are proposed to predict the enhanced strength and stiffness capacity of the lined cold-formed steel studs in load bearing wall components.