This dissertation is based on the published papers during the author’s Ph.D. in the Johns Hopkins University from August 2012 to May 2017. This dissertation includes eight chapters on cold-formed steel modeling rersearch. With the development of structural analysis software, computer simulation becomes an important tool for structural engineers and researchers to understand structural behavior. Structural performance can be evaluated by computer simulation at a low cost in contrast to physical experiments. The research in this dissertation is based on structural analysis and simulation in finite element software. Torsion response for open cross-section members always interests researchers because of its complexity. In Chapter 2, torsion response of typical cold-formed steel members with channel sections is studied. Experimental and simulation results are compared at different boundary conditions. In the end of the chapter, a Direct Strength Method type design expression is provided based on simulation results. Structural members, e.g. beam and column, are elementary components in a building. A subsystem is a higher-level component in a structure, e.g., lateral force resistance system and gravity load resistance system. Shear wall and diaphragm are crucial lateral force resistance subsystems in a building. In Chapter 3, a fastener-based cold-formed steel framed, wood sheathed shear wall was developed and verified with existed shear wall experiments. Chapter 4,5 and 6 are applications of the fastener-based shear wall model. Chapter 7 and 8 are modeling work of bare steel deck panels.