Bending Stiffness of the Floor of the Assembled-Type Light Steel-Modular House

The assembled -type light steel (ATLS) modular house is an emerging type of eco-friendly modular building and has been widely used for buildings with repetitive units. This paper focused on the bending stiffness of the bottom frame of ATLS modular house. The bending stiffness of the full-scale ATLS modular house was tested. It was indicated that the stiffness of the cold-formed thin-walled beam of the bottom floor was weak and the vertical deformation of the beam was obvious. Furthermore, the finite-element (FE) model was developed based on the general purpose finite-element software ABAQUS. The results of the FE model were consistent approximately with the test results in terms of the load–displacement curves at the mid-span of the bottom frame beam, and center of the bottom floor. Based on the verified FE model, the influence of the calcium silicate board, opening of corner fitting, stiffness of bolt connection, and the constraint of corner fitting on the bending stiffness of the bottom frame beam was revealed. The opening of the corner fitting has little effect on the bending stiffness of the floor. The existence of the calcium silicate board can increase the bending stiffness of the floor by 23%. The increase of stiffness of the high-strength bolt connection has less influence on the bending stiffness of the floor. The bending stiffness of the floor decreases by 14.7% when constraining the inside edge of the corner fitting compared to other boundary conditions. The presented experimental and numerical studies will be useful to promote the design of ATLS modular house.